Articles Archive – Canine

Chronic Conditions Dominate this Year’s List of Most Common Pet Health Problems

Nationwide analyzed more than 3.3 million pet insurance claims submitted in 2025 from over one million insured dogs and cats. This year’s analysis underscores a clear and ongoing trend: chronic diseases dominate the most common claims across both species, mirroring what many veterinary healthcare teams observe in practice. These conditions not only contribute to repeat visits, diagnostics, and multimodal management, but also can represent significant cumulative cost over time.

“Each year these findings remind us just how much our pets’ health is shaped by ongoing, chronic conditions,” said Dr. Emily Tincher, chief veterinary officer at Nationwide. “While not every illness can be prevented, early recognition and proactive management can improve outcomes. Our goal is to equip pet families, and the veterinary teams who partner with them, with insights that help support better long-term care.”

USDA approes drug for canine allergic and atopic dermatitis

A newly approved injectable therapy expands treatment options for allergic and atopic dermatitis in dogs, with a U.S. launch planned in the first half of 2026.

January 6, 2026

Elanco Animal Health has received U.S. Department of Agriculture approval for Befrena (tirnovetmab), an anti–IL-31 monoclonal antibody injection for the treatment of canine allergic and atopic dermatitis. According to the company, the product is intended for use in dogs of any age and is recommended at dosing intervals of six to eight weeks following treatment. Elanco expects to launch the product in the first half of 2026.

The approval marks Elanco’s second dermatology-related product clearance in less than 18 months, following Zenrelia (ilunocitinib tablets), an oral JAK inhibitor indicated for itching and inflammation associated with canine skin allergies. Elanco noted that recent updates to the Zenrelia label removed a specific vaccine-related risk statement, while existing boxed warnings on vaccination timing remain in place.

Elanco also cited findings from its “America’s Itchy Dogs Report,” which highlights the prevalence of itch-related skin conditions in dogs and delays in seeking veterinary care.

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The dental is in the details: CT scan in veterinary dentistry

January 7, 2026

By Robert Whitaker

The increase in accessibility and capabilities of computed tomography (CT) technology has understandably led to a growth in its use in the veterinary industry across a variety of applications. Dentistry is an area where CT imaging can be particularly useful, capturing small details to provide an intricate diagnostic resource.

CT in dentistry is likely to continue gaining popularity, and by reviewing the available technology, clinical applications and benefits to veterinarians, patients and owners, that trend makes perfect sense.

Technology with teeth

One of the driving factors in the increased presence of CT scanners in veterinary clinics is the recent addition of a new CT modality to the market. High-definition volumetric imaging (HDVI) builds a 2D and 3D image dataset of the animal patient’s whole density, rather than the traditional method of stacking individual image slices. This provides veterinarians with a much finer level of detail, capturing spatial resolution down to 100 microns within safe radiation levels.

Analyzing small and intricate anatomy is a well-known challenge in the veterinary industry, and dentistry is certainly no exception. An HDVI scan captures the detail necessary to diagnose conditions in tiny structures, like teeth roots in small animals, making it ideal for dental procedures, including:

• Tooth extraction planning. Identifying root fractures, ankylosis and abnormal root morphology, and locating retained roots after incomplete extraction.
• Periodontal disease assessment. Evaluating bone loss patterns around teeth and detecting early or hidden lesions not visible in an X-ray scan.
• Endodontics. Visualizing pulp chamber anatomy, root canals, and periapical lesions, and assessing healing after treatment.
• Oral tumor diagnosis and surgical planning.Determining tumor extent, invasion into the bone, and surgical margins, and mapping complex resections involving the mandible or maxilla.
• Jaw fracture repair. Precisely identifying fracture lines, fragment displacement, and dental involvement, and planning fixation without damaging the tooth roots.
• Orthodontics/malocclusion cases. Assessing unerupted or impacted teeth and measuring jaw symmetry and tooth alignment in 3D.
• Resorptive lesions.Detecting early lesions under the gumline and guiding decisions on extractions or crown amputations in this common feline condition.
• Pre- and post-surgical follow-up.Confirming full removal of diseased tissue and monitoring healing and bone regeneration.

As much of the damage from periodontal conditions happens below the surface of the gumline, it may be easy to forget just how big an impact it can have on veterinary patients. A study on dogs shows regular dental cleanings and treatments of periodontal disease are linked to patients living up to 20 percent longer compared to canine patients that did not receive dental care.¹ This translates to an additional two to four years to the expected lifespan in some breeds.¹ Cats with untreated dental disease are at a higher risk of kidney disease, heart problems and weight loss, conditions that can significantly shorten the animal’s life and increase pain and discomfort.²

This technology can also be applied to exotic patients.

“I’ve had some rabbits in the last year that had very vague signs, things like not eating very well. Looking at their teeth, their dental issues seemed mild, or their teeth looked fine on awake oral exams. I even did a sedated exam, and I didn’t see anything,” says Sari Kanfer, DVM, who practices at Exotic Animal Veterinary Center in Pasadena, Calif.

“Then on CT, I could see the last lower molar was a little infected and loose, so I was able to then put them under anesthesia, extract the tooth and the problems were fixed.”

Animals often hide dental pain, an instinct that can cause both owners and veterinarians to overlook potential issues that impact their quality of life. CT scans can help remove that barrier and provide a full assessment of the animal’s periodontal health, allowing earlier detection and intervention before the condition requires a major procedure.

More than just lip service

In addition to detailed imaging for these and other conditions in the mouth, an HDVI dental scan also captures the fine details of the ears, eyes, and nasal passage. Veterinarians can view the entire skull in 2D and 3D with clear resolution, including both hard and soft tissue details. This provides more context for the patient’s condition and can help further elevate care.

HDVI CT scans are also used for chest, abdominal, and orthopedic imaging in general practice clinics that provide dental services, creating more opportunities for the modality to be utilized and to establish its place in the imaging suite.

As CT technology has continued to evolve, it has also seen improvements in its usability in veterinary settings. Modern machines are significantly faster than previous iterations or other imaging systems used today for dental applications. Oral radiographs on a dental patient can take up to 30 minutes, while an HDVI scan can be completed in less than five minutes. This enables veterinarians to access more detailed diagnostic information more quickly, facilitating rapid assessment and treatment implementation.

The need for anesthesia, a hindrance that can occasionally impede veterinarians’ use of CT scanning, is also not an issue in dental care. Patients are already under anesthesia for the dental exam and cleaning, and a veterinarian can take advantage of this fact by capturing an HDVI scan to visualize everything below the gumline and other surrounding structures and tissues.

Lower cost has been another shift that increases accessibility to CT technology, giving veterinarians more information and power at the point of care. These savings are, in turn, passed on to the client, who can be assured their provider has the data they need to provide informed treatment without an impossible price tag attached to it.

Owners also benefit from the extra visibility provided by CT imaging, particularly HDVI CT. When a veterinarian can use an image to more clearly illustrate a pet’s condition to the owner, compliance with treatment recommendations can increase exponentially. Not only are HDVI scans high-resolution, capturing even the tiniest details, but they can also be rendered in 3D and colorized. The problem can be clearly visualized and explained, allowing the veterinarian to more easily obtain permission to complete the necessary treatment.

On the cuspid of greatness

The advancement of CT technology and its subsequent growth as a cornerstone in veterinary dentistry have already brought it into the spotlight as the gold standard for patient images, and this trend has every indication of continuing.

Ultrasound saw a similar trajectory over the past few decades. In the 1990s and early 2000s, only specialty clinics offered ultrasound machines; now, virtually all veterinary practices have an ultrasound system they use daily.

Dental CT is already a much more established clinic staple than it was just a few years ago. For example, one veterinary group with over 30 locations across the Western U.S. has made dental imaging with an HDVI unit a standard component of all new patient intakes, in addition to regularly using it for diagnosis on existing patients. This is a relatively new and niche feature to offer patients, but as technology continues to become more affordable with additional capabilities like pairing with surgical planning software, it will likely continue to be adopted into more clinics.

December of this year will mark 130 years since Wilhelm Röntgen took the first X-ray. In just a handful of decades, the capabilities of this technology have absolutely skyrocketed from blurry low-contrast pictures to interactive 3D models that accurately illustrate even the tiniest anatomical details. No one knows what the next innovation will be or how it will elevate the tools and information available to veterinarians. However, what we can say with some degree of certainty is that good things are coming in the realm of HDVI, and the next couple of decades will see an even greater improvement in accessibility, capability, client confidence, and patient outcomes.

With nearly three decades in the animal health industry, Robert Whitaker is an experienced animal imaging technician and veterinary business professional. Whitaker has made significant contributions to advancing imaging in food animal, large animal, and small animal applications since 1995. He is the business development director for Veterinary in North America at Imaginalis.

References

1. https://pubmed.ncbi.nlm.nih.gov/11263700/
2. https://us.swedencare.com/pet-life/longevity-in-cats-how-dental-health-impacts-lifespan-and-wellbeing/

Kinesiology taping–does it work? If so, how?

January 20, 2026

By Narda G. Robinson, DO, DVM, MS, FAAMA

As the field of sports medicine and rehabilitation evolves and expands, more of us are recognizing the value of trying non-invasive modalities first, rather than rushing to surgery, for a range of orthopedic problems and mobility disorders.

One of the approaches currently gaining traction is kinesiology taping (KT), a hard-to-miss technique for humans and animals, with its bold colors and intriguing patterns. When audiences see KT worn by human athletes at the Olympics, it surges in popularity. Nonetheless, many skeptics dismiss it as “placebo”¹ or “pseudoscience.”² Fortunately, proponents remain undeterred, citing more and better research that elucidates its mechanisms of action and clinical value.

KT consists of thin, flexible, and “breathable” tape that stretches to allow for movement and, as a result, sensory stimulation. This differs from rigid athletic tape (AT) that limits motion and inhibits neuronal excitation.

For humans, KT attaches directly to skin, much like a Band-Aid. In contrast, veterinary kinesiology tape (VKT) is applied to areas that usually have some amount of fur between the skin and tape, making it harder to stay in place. Some manufacturers of VKT have addressed this concern by opting for thicker material with a stronger, medical-grade adhesive, offering more support and stability. To discourage chewing and ingestion, VKT may have a bitter or unpleasant flavor.

Taping patterns in swirling, crisscrossed, and circular arrangements suggest a rational and clinical intent designed to deliver a specific outcome. In the accompanying images, we see “anchored” Hestaband (a type of VKT) above and below longitudinal tapes over a dog’s tarsus

 

Research considerations

A common criticism of taping techniques pertains to the lack of consistent guidelines and basic standards.³ Determining “best practices” and testing those against other forms of care could dramatically improve the quality and reliability of KT research.

That said, it is nearly impossible to design an inert and convincing sham intervention for physical treatment modalities in the awake patient. That is, placebo surgery would typically require a skin incision. Massage, by definition, makes physical contact with the patient. Similarly, any form of “fake” acupuncture the patient feels impacts the nervous system.

As Kaptchuk et al. wrote, “[S]ham acupuncture is not inert or innocuous. And indeed, most methods of sham acupuncture have somatosensory properties and stimulate mechanoreceptors. Touching the skin anywhere induces a certain amount of sensory stimulation and thereby a possible therapeutic effect.”⁴

Uncertainties and methodological challenges aside, positive findings have emerged that support the premise and purported mechanisms of KT for a multitude of conditions:

• “Current evidence suggested that kinesiology taping could be recommended to improve upper limb function in patients with stroke in pain intensity, shoulder subluxation, general disability, upper extremity function, and the PROM of flexion.”⁵
• “We conclude that ankle balance taping that uses kinesiology tape instantly increased the walking ability of amateur soccer players with lateral ankle sprain. Therefore, ankle balance taping is a useful alternative to prevent and treat ankle sprain of soccer players.”⁶
• “The meta-analysis showed a significant improvement in gait functions (step velocity, step and stride length and reduction in the base of support in dynamics), reduction in the joint range of motion in inversion and eversion, decrease in the muscle activation of the long peroneus and decrease in the postural sway in movement in the mid-lateral direction. It is possible to conclude that KT provides a moderate stabilising (sic) effect on the ankles of the athletes of most popular contact sports with chronic ankle instability.”⁷

Other human conditions showing the value of KT include plantar fasciitis,⁸ hemiplegic shoulder subluxation,⁹ post-operative dental pain,¹⁰ quadriceps muscle strength,¹¹ and low back pain.¹² Patients may experience a variety of benefits following anterior cruciate ligament (ACL) reconstruction such as pain reduction,¹³ faster improvement of range of motion, resolution of edema, and increased thigh circumference.¹⁴ For patients with complete ACL rupture and no surgery, those receiving KT showed greater static stability,¹⁵ proprioception, strength,¹⁶ and functional performance.¹⁷

VKT studies are growing in number, too. For horses, the application of KT to the abdominal musculature increased longitudinal activity at the trot¹⁸ and reduced signs of thoracolumbar epaxial pain.¹⁹ VKT was superior to rigid taping in improving gait and weight transfer in dogs.²⁰

As Christa Veinotte,²¹ the owner and CEO of Hestaband, noted, “Kinesiology taping has become an invaluable tool in veterinary rehabilitation— not just for performance, but for comfort and recovery. It was inevitable that taping would move from human athletics into animal therapy, but it’s rare to see it go the other way. That’s what makes Hestaband unique—we started in the equine and canine world, and now our work with Acadia University is taking those insights back into human research.”

Mechanisms of KT

Delving more into the mechanisms, we find that the benefits of KT fall into three main categories: facilitated blood²² and lymphatic fluid flow, mechanoreceptor-driven analgesia, and strengthened muscles and joints.

When sufficiently adherent to skin or fur, KT lifts the general “gmish” of what’s beneath the surface, giving more space for vessels, nerves, and lymphatic channels to function adequately. How does this help? Tissues traumatized by injury, surgery, and chronic inflammation may compress local vasculature due to concomitant edema, muscle tension, and fascial restriction. Circulation of blood and lymph slows, setting the stage for inadequate oxygenation, carbon dioxide buildup, tissue acidosis, and the detrimental accumulation of metabolic end-products.

Nerves affected by ongoing pressure and oxygen reduction turn to inefficient anaerobic glycolysis for day-to-day energy (ATP) needs. Longstanding energy deficits disrupt the function of sensory, motor, and autonomic nerves, leading to numbness, tingling, weakness, cramping, and thermoregulatory dysfunction. This is where KT comes in—its lifting aspects give nerves room to breathe, impelling fluids to flow and pain to subside. Moreover, when KT activates skin mechanoreceptors, it bolsters endogenous analgesic processes in the brain and spinal cord.

Unhappy nerves may also weaken muscles and destabilize joints. Muscles assist ligaments in preserving the mechanical integrity of arthrodial structures through balanced activation, which resists forces and excessive displacement.

By stimulating somatic afferent fibers in skin, muscles, and across joints, KT cultivates a more normal level of communication throughout the sensorimotor system.²³ KT’s value in rehabilitation medicine is not about structurally supporting joints by limiting motion as athletic tape would do, but rather by physiologically bolstering innate processes that make motor control over joint integrity effective and meaningfully protective. Left uncorrected, impaired reflexes have less ability to prevent repeated microtrauma and, ultimately, joint destruction. Thus, KT’s value in the rehabilitation setting is less about limiting movement and more about bolstering innate injury-preventing processes.

From the larger perspective, with all the ways in which integrative rehabilitation and physical medicine measures—such as VKT—reduce pain, improve function, and support resolution of edema and circulatory compromise, why does our profession all too often fast-track animals to surgery when safer measures exist? The side effects, pain, cost, and trauma from VKT and other rehabilitation modalities are negligible in comparison. Plus, VKT has not been implicated in possibly raising the risk of osteosarcoma … unlike certain surgical procedures, such as the TPLO.²⁴

Narda G. Robinson, DO, DVM, MS, FAAMA, practices osteopathic medicine and veterinary medicine. Dr. Robinson taught science-based integrative medicine at the Colorado State University College of Veterinary Medicine and Biomedical Sciences for 20 years. In 2016, Robinson established CuraCore VET in Fort Collins, Colo., where she teaches medical acupuncture, integrative rehabilitation, medical massage, and other integrative medical approaches. Dr. Robinson is planning to offer certification programs in Sidney, British Columbia, beginning in 2026. Columnists’ opinions do not necessarily reflect those of Veterinary Practice News.

References

1. Luz Junior MA, Sousa MV, Neves LAFS, et al. Kinesio Taping® is not better than placebo in reducing pain and disability in patients with chronic non-specific low back pain: a randomized controlled trial. Braz J Phys Ther. 2015;19(6):482-490.
2. Oakford GC. Elastic kinesiology tape is eye-catching, but is it effective? The Chronicle of the Horse. July 14 & 21, 2014. Accessed on 11-11-25 at https://thehorseinmotion.com/wp-content/uploads/2017/05/CHRONICLE-Equine-Kinesiology-Taping.pdf
3. Andrýsková A, Lee JH. The Guidelines for Application of Kinesiology Tape for Prevention and Treatment of Sports Injuries. Healthcare (Basel). 2020 May 26;8(2):144.
4. Kaptchuk TJ, Chen K-J, and Song J. Recent trials of acupuncture in the West: Responses from practitioners. Chin J Integr Med. 2010 Aug 8;16(3):197–203.
5. Wang Y, Li X, Sun C, Xu R. Effectiveness of kinesiology taping on the functions of upper limbs in patients with stroke: a meta-analysis of randomized trial. Neurol Sci. 2022 Jul;43(7):4145-4156.
6. Kim MK, Shin YJ. Immediate Effects of Ankle Balance Taping with Kinesiology Tape for Amateur Soccer Players with Lateral Ankle Sprain: A Randomized Cross-Over Design. Med Sci Monit. 2017 Nov 21;23:5534-5541.
7. Biz C, Nicoletti P, Tomasin M, Bragazzi NL, Di Rubbo G, Ruggieri P. Is Kinesio Taping Effective for Sport Performance and Ankle Function of Athletes with Chronic Ankle Instability (CAI)? A Systematic Review and Meta-Analysis. Medicina (Kaunas). 2022 Apr 29;58(5):620.
8. García-Gomariz C, García-Martínez MT, Alcahuz-Griñán M, Hernández-Guillén D, Blasco JM. Effects on pain of kinesiology tape in patients with plantar fasciitis: a randomized controlled study. Disabil Rehabil. 2024 Nov;46(23):5490-5496.
9. Yim J, Kim B. Effectiveness of Shoulder Taping in Treating Hemiplegic Shoulder Subluxation: A Randomized Controlled Study of 35 Patients. Med Sci Monit. 2024 May 31;30:e944222.
10. Zheng X, Luo S, Huang C, Wang Z, Lin X. Comparison of kinesiology tape and cryotherapy on postoperative reaction following third molar extraction: a randomized clinical trial. Quintessence Int. 2022 Sep 16;53(9):772-777.
11. Choi IR, Lee JH. Effect of kinesiology tape application direction on quadriceps strength. Medicine (Baltimore). 2018 Jun;97(24):e11038.
12. Abbasi S, Hadian Rasanani MR, Ghotbi N, Olyaei GR, Bozorgmehr A, Rasouli O. Short-term effect of kinesiology taping on pain, functional disability and lumbar proprioception in individuals with nonspecific chronic low back pain: a double-blinded, randomized trial. Chiropr Man Therap. 2020 Nov 20;28(1):63.
13. Chan MC, Wee JW, Lim MH. Does Kinesiology Taping Improve the Early Postoperative Outcomes in Anterior Cruciate Ligament Reconstruction? A Randomized Controlled Study. Clin J Sport Med. 2017 May;27(3):260-265.
14. Boguszewski D, Tomaszewska I, Adamczyk JG, Białoszewski D. Evaluation of effectiveness of kinesiology taping as an adjunct to rehabilitation following anterior cruciate ligament reconstruction. Preliminary report. Ortop Traumatol Rehabil. 2013 Oct 31;15(5):469-78.
15. Ogrodzka-Ciechanowicz K, Głąb G, Ślusarski J, Gądek A, Nawara J. Does kinesiotaping can improve static stability of the knee after anterior cruciate ligament rupture? A randomized single-blind, placebo-controlled trial. BMC Sports Sci Med Rehabil. 2021 Mar 16;13(1):24.
16. Kielė D, Solianik R. Four-Week Application of Kinesiotaping Improves Proprioception, Strength, and Balance in Individuals with Complete Anterior Cruciate Ligament Rupture. J Strength Cond Res. 2023 Jan 1;37(1):213-219.
17. Liu K, Qian J, Gao Q, Ruan B. Effects of Kinesio taping of the knee on proprioception, balance, and functional performance in patients with anterior cruciate ligament rupture: A retrospective case series. Medicine (Baltimore). 2019 Nov;98(48):e17956.
18. Biau S, Burgaud I. Application of kinesiology taping to equine abdominal musculature in a tension frame for muscle facilitation increases longitudinal activity at the trot. Equine Vet J. 2022 Sep;54(5):973-978.
19. King MR, Pavsek H, Ellis KL, et al. J Equine Rehabilitation. Volume 2, 2024, 100007. Accessed on 11-12-25 at https://www.sciencedirect.com/science/article/pii/S2949905424000021?via%3Dihub .
20. Altinkaya N, Pekyavas NO, and Gungor GC. Immediate effects of kinesiotape on gait and static weight-bearing in dog. J Hellenic Vet Med Soc. 2025;76 (1):8829-8836.
21. Christa Veinotte is the founder of Hestaband, a Canadian-based kinesiology tape brand developed specifically for use in veterinary medicine. Veinotte continues to educate and collaborate with professionals worldwide to expand the understanding and practical application of taping in veterinary care.
22. Craighead DH, Shank SW, Volz KM, Alexander LM. Kinesiology tape modestly increases skin blood flow regardless of tape application technique. J Perform Health Res. 2017.
23. Riemann BL and Lephart SM. The sensorimotor system, Part I: The physiologic basis of functional joint stability. J Athl Train. 2002;37(1):71-79.
24. S Selmic LE, Ryan SD, Ruple A, Pass WE, Withrow SJ. Association of tibial plateau leveling osteotomy with proximal tibial osteosarcoma in dogs. J Am Vet Med Assoc. 2018 Sep 15;253(6):752-756. doi: 10.2460/javma.253.6.752

Have You Heard of the Chevron Lucency?

February 3, 2026

By John R. Lewis, VMD, DAVDC, Fellow, AVDC OMFS

Interpreting dental radiographs in dogs and cats can be challenging, particularly when assessing teeth for possible endodontic disease. The classic radiographic signs of endodontic disease include: 1) a wider than normal root canal, 2) periapical resorption and/or internal resorption of the root and 3) lucency of the bone surrounding the root apex, a.k.a. “periapical lucency.”

Let’s discuss each of these radiographic signs individually:

1) A wide canal

A wider than normal root canal is a reliable and specific sign of an endodontically diseased tooth, but the sensitivity of this finding is low, because it takes a long time for an endodontically diseased tooth to show evidence of this radiographic sign.

Think of a tooth as a tree, except the rings of the tree are laid down internally. The diameter of the tooth does not change, but the width of the canal gets narrower over time as a vital, living tooth continues to age. The hard tissue, dentin, is produced throughout the life of the tooth by cells lining the pulp called odontoblasts. Odontoblasts produce primary dentin when the tooth is developing. Secondary dentin is produced after eruption and throughout the life of the tooth. Odontoblasts can even produce a reparative dentin (tertiary dentin) in response to wear of the tooth. If the cells within the pulp die due to endodontic disease, the lack of odontoblasts results in a cessation of maturation of the tooth and a wider canal than the contralateral tooth. It takes months for this discrepancy in canal width to be radiographically evident.

2) Tooth resorption

Resorption of the hard tissue of the root can occur in the area of the apical delta or anywhere within the canal as a result of infection and inflammation. When it occurs within the canal, internal resorption manifests radiographically as a focal widening of the canal, often in the mid-root area. When resorption occurs around the apex of the root, it results in an irregular surface of the normally smooth, dense hard tissue of the tooth root.

3) Periapical lucency

Periapical lucency can be evidence of periapical infection/inflammation. Normally, the apex of the root is surrounded by a narrow periodontal ligament space, which is radiolucent on radiographs. Adjacent to the periodontal ligament space, there is a thin layer of radiodense bone called lamina dura. When infection becomes established in the apical portion of the root, the bone of the lamina dura is lost, resulting in a periapical lucency that is often wider than the diameter of the tip of the root. Though this appearance is often referred to as a “tooth root abscess,” in reality, abscess is only one of the many possible reasons for a periapical lucency. Perhaps the most common cause of periapical lucency is a granuloma rather than a true abscess. Granulomas can sometimes be seen as a large ball of soft tissue attached to the root when extracting an endodontically diseased tooth. Periapical cysts can also cause a periapical lucency, but unlike abscesses or granulomas, a cyst often has a corticated border around the periapical lucency.

One of the most commonly mistaken normal variants that can mimic a pathologic periapical lucency is the chevron radiolucency. Frequently seen at the apices of canine teeth, molars and maxillary incisors of dogs, the chevron lucency represents trabecular bone and vascular channels rather than true periapical lysis.¹

Other normal jaw structures may appear on radiographs and mimic pathology. In the maxillary canine and premolar region in dogs, the junction of the vertical body of the maxilla with its palatine process and the maxillary conchal crest—can mimic a cystic structure and interfere with evaluating apical structures. In the mandible, the canal and various mental foramina are normal radiolucent structures that may superimpose over a root, depending on the angle and exposure.

Distinguishing normal variants from true endodontic disease

How can we determine if a lucency is pathologic or anatomic? Sometimes, even for board-certified dentists who interpret dental radiographs daily, it can be difficult to determine.

Chevron lucencies usually extend apically at the same width of the apex instead of expanding beyond the dimensions of the apex, and are surrounded by a distinct periodontal ligament and lamina dura.

Normal anatomical variations often present with regular, well-defined margins. Pathologic changes, by contrast, tend to be mottled, irregular, or “moth-eaten” in character. Normal variants are typically bilaterally symmetrical or follow predictable patterns related to jaw or tooth anatomy. Disease processes usually involve asymmetric destruction or expansion of bone or tooth structure.

Clinical clues matter. When trying to determine if radiographic findings are truly significant, evaluate for signs such as tooth abrasion, discoloration (intrinsic staining), fracture, pulp exposure, swelling over the roots, and draining tracts. Normal anatomical variants often occur in teeth that have no other signs of trauma. If there are no clinical signs of disease, consider monitoring the tooth with serial radiographs to look for changes over time, which will distinguish stable anatomical variants from progressive pathologies.

I hope this helps you with some of your future radiographic challenges. In next month’s column, we will continue to discuss diagnostic imaging modalities of the mouth, head, and neck.

John R. Lewis, VMD, DAVDC, FF-OMFS practices at Veterinary Dentistry Specialists and teaches at Silo Academy Education Center, both in Chadds Ford, Pa.

Reference

1. DuPont GA, DeBowes LJ. Atlas of Dental Radiography in Dogs and Cats. Saunders Elsevier; St. Louis (2009): p. 150.

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Veterinary Practice News I Geriatric pain: A look at common considerations for pain management in senior pets 

Let’s break down pharmaceutical and non-pharmaceutical options when dealing with pain in apparently healthy geriatric patients. 

By Michael C. Petty, DVM

January 8, 2026

In general terms, geriatric patients are defined as those that have completed 75-80 percent of their anticipated life span.1 In humans, geriatric comorbidities are the main cause of mortality during anesthesia.2 There is no reason to think it is any different in our dogs and cats. The second largest reason is that in most geriatric patients, there is a decline in the normal “reserve capacity” which can impede their response to situations of stress, such as hospitalization and surgery.3

Not all dogs and cats have issues with major organ systems, but those of high consideration are the cardiovascular system, major organs, such as the liver and kidneys, and the respiratory system. Additionally, for unknown reasons, older patients require less injectable and inhalant anesthetic drugs to produce general anesthesia.4

The following is a list of common considerations when dealing with apparently healthy geriatric patients. It is not intended to serve as a guide for geriatric patients with significant or profound comorbidities. Additionally, this writing concentrates on pain management, which also overlaps with anesthetic protocols. It is not meant to be a guide for induction or maintenance of anesthesia.

Pharmaceutical considerations: Acute pain Opioids are amazing pain drugs when used in acute pain settings, such as pre- and post-surgery, and in the case of trauma. Opioids are generally the safest and most effective agents available for the treatment of acute pain. Although many of us were taught to fear the serious side effects of opioids, these concerns were inappropriately extrapolated from experiences in human medicine.5 Opioids work on several levels, including the inhibition of pain at peripheral nociceptors, modulation of the pain signal in the spinal pathway, and reduced perception of pain in the brain. Modification of opioid doses for geriatric animals is not needed.

Opioids can be classified into three types:

• Full agonists. These opioids produce dose-dependent analgesia—that is, the more administered (within safety limits), the greater the effect. They bind and fully activate opioid receptors, particularly the μ receptor. Clinical application: Used for procedures that have the potential for causing severe pain, including perioperative and trauma pain.

• Partial agonists. Partial agonists bind to opioid receptors with high affinity but produce a submaximal effect, even at higher doses. This ceiling effect limits both their analgesic potential and their potential side effects. Clinical application: Appropriate for mild to moderate pain.

• Agonist-antagonists. These drugs act as agonists at some opioid receptors (typically κ) and antagonists at others (typically μ). This class of opioids rarely causes dysphoria. They may displace full agonists from the μ receptor, potentially reversing their effects. Clinical application: Used for mild to moderate pain. They are useful for opioid reversal when dysphoria occurs with full agonists but still allow partial maintenance of analgesia.

Morphine is the prototypical opioid against which other opioids are measured. It is extremely safe, with minimal cardiovascular and respiratory effects. As a full agonist, it is reversible. Morphine can cause a decrease in GI motility, which should not be of clinical importance when used short-term, such as for surgery. It also causes vomiting, especially in those patients that receive it prior to surgery.

Morphine can be given subcutaneously, intramuscularly, or very slowly intravenously to avoid histamine release. It has a rapid onset of action, occurring within three to five minutes, and provides analgesia for two to four hours.

Note: Morphine is potentially less effective in cats than it is in dogs, as cats only benefit from the parent drug but cannot make the intermediate metabolite.

Hydromorphone It is very similar to morphine in terms of onset and duration. All opioids can cause hyperthermia; however, it has been implicated, maybe wrongly, to be more severe in cats. One study showed all opioids tested caused a mild increase in body temperature.6 This is usually a self-limiting issue and may also be more closely associated with post-emergent dysphoria following sedation or general anesthesia.

Methadone Very similar to morphine but also has some N-methyl-D-aspartate (NMDA) antagonist activity. Methadone causes little nausea and is less likely to cause dysphoria compared to other full agonists.

Fentanyl A very potent opioid given intravenously as either a constant rate infusion or as a bolus. It has a rapid onset of action, typically occurring within two to five minutes. It is less likely to cause GI effects or dysphoria compared to the other full agonists.

Buprenorphine This has moderate potency compared to the full agonists, so consideration must be given for the surgical procedure to be performed. It has a long onset of action, as much as 30 minutes, but also has a long duration of action, typically in the six- to eight-hour range. Given to cats as the concentrated form of Simbadol, it can provide analgesia for 24 hours.

Butorphanol This agonist-antagonist is moderately potent, with an onset of action of one to five minutes when administered IV or IM. However, it has a short duration of action, ranging from 45 minutes. It has an excellent sedative effect, which can last several hours. This sedative effect is often confused with the much shorter analgesic effect.

Alpha-2 Agonists Alpha-2 agonists—primarily dexmedetomidine, medetomidine, and xylazine—are sedative-analgesic agents commonly used in veterinary practice. Their mechanism of action involves stimulation of central α₂-adrenoceptors, resulting in sedation, analgesia, and muscle relaxation, as well as dose-sparing effects on other anesthetic agents.

Dexmedetomidine is the most commonly used alpha-2 agonist due to its higher receptor selectivity and favorable pharmacodynamic profile.

Clinical use of alpha-2 agonists:

As premedication in balanced anesthesia protocols For sedation when combined with other agents (e.g. opioids, ketamine) Occasionally, as part of multimodal analgesia during painful procedures or in recovery. Note: Atipamezole is a specific antagonist and should always be available when using this class of drugs When combined with opioids, the recommended dose of dexmedetomidine is 0.5–2 µg/kg IM. Always dose based on lean body mass, not total weight. Special considerations when using alpha-2 in geriatric or compromised patients: Due to age-related reductions in cardiac output, vascular compliance, and organ perfusion, alpha-2 agonists must be used with extreme caution in geriatric animals. Avoid their use as a stand-alone sedative in older patients. Instead, consider combining with opioids for pre-anesthesia or combining with ketamine and opioids for procedural sedation. 

The disadvantages of using alpha-2 agonists include emesis, muscle twitching and tremors, reflexive bradycardia due to increased central blood pressure, and reduced cardiac output.

Ketamine Ketamine is a dissociative anesthetic widely used in veterinary medicine for induction, sedation, and analgesia. It functions primarily as an NMDA receptor antagonist, disrupting nociceptive signal transmission and preventing central sensitization. Ketamine is most effective when combined with other agents, such as opioids and alpha-2 agonists, particularly in multimodal analgesia protocols.

Ketamine provides excellent somatic analgesia. However, it has poor visceral analgesia, making it a poor choice for intra-abdominal procedures. It also has the advantage of a rapid onset and a long duration of action. Its ability to maintain cardiovascular and respiratory function makes it a potential option for geriatric patients that do not have significant cardiovascular or respiratory disease.

There are some disadvantages with ketamine, including hypersalivation, increased muscle tone resulting in a rigid appearance, lack of a blink response requiring ophthalmic lubrication, and rough recoveries when used as a sole agent. Patients may experience vocalization, tremors, or dysphoria. 

It is advisable not to administer NSAIDs preoperatively unless there are provisions for closely monitoring for a drop in blood pressure, and the attending veterinary staff have the necessary pharmaceuticals and skill set to respond appropriately to a blood pressure drop. Many veterinarians prefer to start NSAIDs during the immediate post-anesthetic recovery.

Local anesthetics Local anesthetics can and should be used whenever possible. As the only true analgesic, it can have a profound effect on patient comfort, as well as safety, as the use of local anesthetics will reduce the need and dosage of other analgesics. There are no contraindications specific to geriatric patients. The usual precautions of dose and route of administration are the same across all age groups.

Non-pharmaceutical considerations Geriatric pets may become disoriented in the unfamiliar surroundings of a veterinary hospital. This can interfere with both eating and sleeping, which have been shown to impact recovery in all age groups, but is decidedly a more important consideration in geriatrics that may have comorbidities. It is essential that we consider the factors that impact sleep7 and nutrition.8

Michael C. Petty, DVM, is a veterinary school graduate from Michigan State University. Dr. Petty has devoted his professional life to the care and well-being of animals, especially in pain management. Petty is the past president of the International Veterinary Academy of Pain Management and current World Small Animal Association Pain Council member. A frequent speaker and consultant, he has published articles in veterinary journals and serves in an advisory capacity to several pharmaceutical companies on pain management topics. Petty has been the investigator/veterinarian in 12 FDA pilot and pivotal studies for pain management products. He has lectured both nationally and internationally on pain management topics.

References 

1. Dodman NH, Seeler DC, Court MH. Aging changes in the geriatric dog and their impact on anesthesia. Compendium on Continuing Education for the Practicing Veterinarian. 1984;6:1106–1113.
2. Muravchick S. The aging process: anesthetic implications. Acta anaesthesiologica Belgica. 1998;49:85–90.
3. Conzen P, Peter K. Inhalation anaesthesia at the extremes of age: geriatric anaesthesia. Anaesthesia. 1995;50(Suppl):29–33. doi: 10.1111/j.1365-2044.1995.tb06187.x.
4. Hughes J. Anaesthesia for the geriatric dog and cat. Ir Vet J. 2008 Jun 1;61(6):380-7
5. Hansen B. Acute Pain Management. Veterinary Clinics of NA, Small Animal. K Mathews, ed. 2000;4:899‐916.
6. Posner LP, et al. Vet Anaesth Analg. 2010;37(1):35-43.
7. Emma A. Devereux, Alana V. Ejezie, Alex M. Lynch, Margaret E. Gruen, Stefanie J. LaJuett, James B. Robertson, Valery F. Scharf Factors Affecting Sleep Among Dogs and Cats in a Veterinary Intensive Care Unit, Journal of Veterinary Emergency and Critical Care: 2025;Volume 35, Issue 3:252-232
8. Collins, S. (2016). The importance of nutrition in the post-operative recovery of cats and dogs. Veterinary Nursing Journal, 31(8), 233–236. https://doi.org/10.1080/17415349.2016.1194637

https://www.veterinarypracticenews.com/geriatric-pain-common-pharmacuetical-non-pharmaceutical-considerations/

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DVM 360 News | Key takeaways from AAHA’s 2026 oncology guidelines

Author(s)Bob Alaburda, Associate Editorial Director

January 7, 2026

AAHA’s 2026 oncology guidelines aim to update diagnostics, staging, treatment priorities, and team workflows to help primary care clinics detect, stage, and manage cancer while preserving patient quality of life. 

Cancer is a leading cause of illness and death in older dogs and cats, affecting roughly 50% of dogs and about 30% of cats older than 10 years. The American Animal Hospital Association’s (AAHA) 2026 Oncology Guidelines synthesize current evidence and expert consensus into actionable recommendations for the primary care team from diagnosis and staging to treatment options, supportive care, referral triggers, and follow-up.1,2

Here are a few key takeaways. A link to the full guidelines can be found in the reference list below this article.

Make a definitive diagnosis before planning therapy

AAHA emphasizes that a cytologic or histopathologic diagnosis is necessary to determine prognosis and guide therapy.1-3 When fine-needle aspirate is inconclusive or additional information is required (for example, tumor grade), pursue biopsy and histopathology rather than assuming tumor behavior.3

Use staging to guide treatment intent and timing

Staging is more than local vs metastatic classification. It clarifies treatment intent (curative vs palliative) and identifies appropriate imaging and nodal assessment. AAHA provides tumor-specific staging checklists and recommends thoracic imaging, abdominal ultrasound, and regional lymph node cytology or biopsy as indicated.3 

Frame chemotherapy around quality of life

The primary goal of systemic therapy in veterinary oncology is maintaining the best possible quality of life while controlling disease. Most veterinary chemotherapy protocols are generally well tolerated. Adverse events are usually manageable when clinicians and owners anticipate them and monitor appropriately.1,4

Educate owners proactively about the likelihood of appetite changes during chemotherapy and provide concrete management strategies. Addressing appetite loss early helps pets remain on recommended treatment plans and improves overall well-being during therapy.1

Evaluate new drugs and biologics carefully

The guidelines stress understanding the risks, benefits, cost, and regulatory status of novel therapeutics (such as small-molecule inhibitors, monoclonal antibodies, and other biologics). Clinicians should not adopt new agents without reviewing available evidence, registration status, and monitoring requirements.4 

Integrate supportive and symptomatic care from diagnosis onward

Supportive care—nutrition, pain management, antiemetics, wound and infection management, and psychosocial support for owners—is fundamental and begins at diagnosis. AAHA provides screening and treatment checklists aimed at maintaining function and comfort throughout therapy and survivorship.7,8 When initiating symptomatic care, thoroughly evaluate for comorbidities that may alter drug choice, dosing, or prognosis. This ensures supportive measures truly improve quality of life rather than introducing harm.1 

Optimize the veterinary team’s role

Technicians and other team members play a central role in oncology workflows, including intake screening, weight and appetite tracking, pain scoring, client education, medication administration training, and documentation. Standardized technician checkpoints improve early detection of complications and support better quality-of-life decisions.8 

Know when to refer and how to collaborate

AAHA outlines clear referral triggers: complex staging that requires advanced imaging, specialized surgery, administration of advanced systemic protocols, or when weighing curative versus palliative intent. Good referral relationships and succinct transfer-of-care notes streamline transitions and may improve outcomes.5,6 

Adopt structured post-treatment monitoring

Tumor-specific follow-up schedules and standardized monitoring (physical exam, imaging, and laboratory testing) are recommended to detect recurrence or late treatment effects early. Integrating these schedules into practice management software reduces the risk of patients being lost to follow-up.9

References

1. American Animal Hospital Association. 2026 AAHA oncology guidelines for dogs and cats. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/

1. American Animal Hospital Association. Section 1: overview of common cancers. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-1-overview-of-common-cancers/

1. American Animal Hospital Association. Section 3: tumor diagnostics and staging. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-3-tumor-diagnostics-staging/

1. American Animal Hospital Association. Section 5: therapeutic interventions. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-5-therapeutic-interventions/

1. American Animal Hospital Association. Section 6: consultations and referrals. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-6-consultations-and-referrals/

1. American Animal Hospital Association. Section 2: what’s new in veterinary oncology. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-2-whats-new-in-veterinary-oncology/

1. American Animal Hospital Association. Section 7: supportive and symptomatic care. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-7-supportive-and-symptomatic-care/

1. American Animal Hospital Association. Section 8: technician and team optimization. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-8-technician-and-team-optimization/

1. American Animal Hospital Association. Section 9: post-treatment monitoring and follow-up care. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-9-post-treatment-monitoring-and-follow-up-care/

https://www.dvm360.com/view/key-takeaways-from-aaha-s-2026-oncology-guidelines

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DVM360 | USDA approves new Anti-IL31 monoclonal antibody injection

Author(s)Caitlin McCafferty, Editor

January 2, 2026

On December 31, 2025, Elanco Animal Health received approval from the USDA for tirnovetmab (Befrena; Elanco Animal Health), an anti-IL31 monoclonal antibody injection that targets canine allergic and atopic dermatitis. The new product Befrena is recommended in dosing intervals of 6-8 weeks post treatment compared to its competitor that is currently on the market that recommends 4-8 weeks post treatment.

“The animal health sector is increasingly focused on antibody-based therapies, and today’s approval is an important step forward in delivering high-impact innovation that enhances the quality of life for pets,” said Ellen de Brabander, PhD, executive vice president of research & development at Elanco, in an organizational release.1 “We are pleased to offer veterinarians and pet owners Befrena, which delivers long lasting relief to treat dogs with allergic itch.”

According to the release, Befrena is the second dermatology product from Elanco to receive approval in less than 18 months and now joins Zenrelia in its dermatology portfolio. Befrena will launch in the first half of 2026.1

In 2025, Elanco released its first report highlighting the impact itching has on canine patients, clients, and veterinary teams in its America’s Itchy Dogs Report. The report, made up of findings from multiple surveys of pet owners and veterinarians, revealed that 9 out of 10 dogs in the US are ‘itchy dogs’ and have experienced symptoms of itchiness at some point in the year according to their owners, which is nearly 79 million dogs.2 The study also found that clients spend around $400 on over-the-counter remedies and wait 6 weeks before bringing their pet to their veterinarian because they typically try to find solutions at home before seeking veterinary care. Because of this, pets whose owners waited too long to bring them in resulted in raw and infected skin as well as owners who are irritated because they want their pet to have some relief.3,4

Research coming out of Elanco, according to their release, stated that nearly 70% of veterinarians would be willing to stock another dermatology product in their clinic to help more patients find itch relief.

“Veterinarians need more options for itch relief so they can offer targeted therapy that focuses on mode of action to meet the unique needs of the individual patient to deliver fast, effective and valuable itch relief,” said Joya Griffin, DVM, DACVD, veterinary dermatologist. “USDA approval of Befrena brings veterinarians a step closer to having another beneficial and safe treatment option. I’m excited to collaborate with Elanco and plan to offer this product in my practice when it becomes available.”

References

1. Elanco Receives USDA Approval for Befrena (tirnovetmab), a New Anti-IL31 Monoclonal Antibody Injection Targeting Canine Allergic and Atopic Dermatitis. News release. Elanco Animal Health. December 31, 2025. Accessed January 2, 2026. https://www.elanco.com/us/newsroom/press-releases/befrena-usda-approval

1. Elanco Animal Health. America’s Itchy Dogs. Accessed January 2, 2026. https://assets.elanco.com/0cec44ed-3eaa-0009-2029-666567e7e4de/33474a48-bac3-4fc4-b7fc-3589b88560fb/ElancoItchyDogsReportFINAL.pdf

1. Elanco Animal Health. Data on File.

1. Elanco Animal Health. Data on File.

https://www.dvm360.com/view/usda-approves-new-anti-il31-monoclonal-antibody-injection

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AVMA News I Wisconsin dog breeder, facing allegations of animal abuse, will no longer supply dogs for research

Published on December 31, 2025

Ridglan Farms, the nation’s second-largest research dog breeder, will stop supplying animals to laboratories under a settlement to avoid criminal prosecution, according to media reports.

This comes as the Beagle breeder, based in Blue Mounds, Wisconsin, faces allegations of animal abuse.

The Dane County Board of Supervisors in October adopted Resolution 119 calling on the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP) to revoke Ridglan’s state-issued commercial dog breeder license.

A judge has also upheld the Wisconsin Veterinary Examining Board’s emergency suspension of Dr. Rick Van Domelen, the lead veterinarian and facility manager at Ridglan Farms.

Ridglan Farms was charged with 311 violations of Wisconsin Administrative Code, including failing to handle dogs “in a humane manner that does not cause physical harm or unnecessary injury.”

It will surrender its DATCP license by July 1, 2026, under the settlement with the state.

Ridglan Farms was under criminal investigation for potential violations of state statutes banning mistreatment of animals and mandating proper shelter, after the appointment of a special prosecutor by the Circuit Court to conduct an independent inquiry into animal cruelty allegations.

The surrender of Ridglan’s license will leave only two major research dog breeders in the U.S.: Marshall Farms in North Rose, New York, and Oak Hill Genetics in Ewing, Illinois.

https://www.avma.org/news/wisconsin-dog-breeder-facing-allegations-animal-abuse-will-no-longer-supply-dogs-research

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AVMA News I The Canine Cognitive Dysfunction Syndrome Working Group guidelines for diagnosis and monitoring of canine cognitive dysfunction syndrome

Natasha J. Olby,VetMB, PhD, DACVIM, Joseph A. Araujo, BSc, Margaret E. Gruen, DVM, PhD, DACVB, Phillipa Johnson, BVSc, MSc, DECVDI, Eniko Kubinyi,PhD

December 24, 2025

Abstract

Canine cognitive dysfunction syndrome (CCDS) is diagnosed with increasing frequency, yet standardized diagnostic guidelines are lacking. The CCDS Working Group, an international group combining experts in the field and primary care veterinarians, proposes a definition of the syndrome and practical diagnostic criteria designed to aid clinicians and researchers alike. Canine cognitive dysfunction syndrome is defined as a chronic, progressive, age-associated neurodegenerative syndrome, characterized by cognitive and behavioral changes that affect daily life to varying degrees. These changes affect the behavioral domains of disorientation, social interaction, sleep disruption, house soiling, learning and memory, activity changes, and anxiety (DISHAA). We propose 3 severity stages. In mild CCDS, signs are subtle and of low frequency or severity, with preserved function. With progression, behavioral changes become more apparent and impactful, requiring management adjustments. In severe CCDS, debilitating deficits are overt, significantly impairing basic functions and necessitating comprehensive support. Two diagnostic levels are proposed. Level 1 is based on consistent history of progressive DISHAA signs, identification of alternate causes through physical, orthopedic, and neurologic examination and laboratory work; either normal neurologic examination or evidence of symmetrical, diffuse forebrain dysfunction; and persistence of signs following management of relevant comorbidities. Level 2 includes a brain MRI showing cortical atrophy with CSF cell counts within normal limits. Definitive postmortem histopathological confirmation rests on cortical atrophy, amyloid deposition, myelin loss, neuroinflammation, and amyloid angiopathy. Future priorities include the development of blood biomarkers and cognitive testing batteries for routine clinical settings, both of which will refine diagnostic accuracy and therapeutic monitoring. 

Introduction

With increasing canine lifespan, age-related conditions like canine cognitive dysfunction syndrome (CCDS) have become more clinically important.1,2 However, diagnosis is challenging: signs are insidious and nonspecific, structural MRI changes emerge late, normal versus pathological decline is difficult to distinguish, and comorbidities further complicate interpretation. Recognizing CCDS early, when intervention may be most impactful, requires understanding of its spectrum and staging.1,2

Canine cognitive dysfunction syndrome has many parallels with Alzheimer disease (AD). Diagnostic guidelines for AD were first introduced in 1984 and have evolved with the understanding of the disease. Components of an antemortem diagnosis encompass history, core clinical criteria including cognitive or behavioral impairment in at least 2 defined domains, as well as blood, CSF, and imaging biomarkers. A final histopathological diagnosis requires certain criteria to be met (eg, scoring amyloid and neuritic plaques and staging neurofibrillary tangles).3–5 As AD diagnostic guidelines have evolved, the antemortem diagnostic accuracy has improved, facilitating timely care and supporting clinical trials. Similarly, unified diagnostic standards for CCDS are needed, with the intent to revise these standards as new data become available. 

Problem Statement

Currently, there are no consensus-based diagnostic guidelines for CCDS. This absence contributes to diagnostic inaccuracy, impedes appropriate therapeutic decision-making and monitoring, and hinders the advancement of research efforts.

We are relatively early in our understanding of the clinical evolution of CCDS, and while biomarkers and cognitive testing are used in research settings, their application in routine clinical settings remains limited.1 There is a substantial body of data on cognitive aging in laboratory-bred Beagles,6 but the clinical picture in companion dogs is less well defined. Even standardized parameters to make a clear imaging or histopathological diagnosis are lacking. Caregiver questionnaires provide a practical way to capture behavioral changes and are important for monitoring and grading severity, given the difficulty in establishing cognitive status during a routine veterinary appointment and the expense and risks of a comprehensive diagnostic workup. However, responder bias and the influence of comorbid conditions limit their specificity, and current questionnaires should not be considered stand-alone diagnostic tools.

Proposed Solutions

The goal of this working group was to bring experts with diverse experience in CCDS together to accomplish the following: 

Evaluate the published information on age-related canine cognitive decline and CCDS.

Provide a definition of CCDS and suggest practical criteria for establishing a diagnosis with 2 levels of certainty. These criteria are based on current knowledge and will be revised as understanding of the syndrome progresses. 

Develop a severity grading of CCDS. 

Definition of CCDS

Canine cognitive decline syndrome is a chronic, progressive age-associated neurodegenerative syndrome characterized by changes in cognitive function that are severe enough to affect daily life to varying degrees.

 This syndrome manifests as changes in the following behavioral domains captured by the acronym DISHAA: 

• Disorientation 

• Impaired social interactions 

• Sleep disturbances 

• House soiling, learning, and memory deficits 

• Activity changes (increased or decreased) 

• Anxiety and fear (increased)

We propose that the term canine cognitive dysfunction syndrome should be considered an umbrella term for canine dementia. While amyloid and tau-associated pathology are recognized, other forms of neurodegenerative processes have not yet been explored and it is likely that different etiological processes exist.

Grading Severity

The following definitions of severity are proposed:

Mild CCDS: behavioral changes are subtle and at low frequency or severity; the dog is generally able to perform normal functions; changes are frequently attributed to old age by caregivers and may be missed unless specifically screened.

Moderate CCDS: behavioral changes are more frequent and severe, interfering with normal daily activities and requiring management adjustments.

Severe CCDS: behavioral changes are overt and debilitating; the dog needs support even for basic functions, and comprehensive management is needed.

These definitions reflect owners’ perception of their dog’s degree of disability rather than quantifying the pathology but provide a practical, relevant means of establishing syndrome stage.

Clinical Presentation

The caregiver history should describe slowly progressive behavioral changes that reflect deteriorating cognitive function. These signs are often described with the acronym DISHAA as listed in the definition.7,8 Dogs with CCDS will present with changes in one (early disease) or more of these behavioral domains, with recent studies suggesting that nighttime restlessness, decreased daytime activity, and changes in social interaction occur early in the disease, while house soiling and spatial disorientation are seen as disease severity increases.9–11 The characteristics of these signs might also vary by individual. For example, disorientation might present as going to the wrong side of doors, seeming to stare into space, or not recognizing caregivers (among others), while changes in activity might present as being less playful or active or showing increased repetitive or aimless activity. Similarly, changes in social interaction might include both increased (displaying attention-seeking behaviors) or decreased social behaviors. While many of these clinical signs affect quality of life for both dogs and their caregivers, changes in the sleep-wake cycle are often associated with increased caregiver burden.12 Caregivers also report sensory impairments (hearing, vision, and smell) and postural instability.13

It is critical to remember that CCDS remains a diagnosis of exclusion. Advancing age is associated with changes in all body systems, and many disease states can contribute to the behavioral changes within the DISHAA domains14 (Supplementary Table S1). A detailed physical examination that includes orthopedic, ophthalmic, and neurologic examinations is indicated, and a minimum database of CBC, serum chemistry panel, urinalysis, and blood pressure measurement should be offered. Full evaluation of each differential for the signs shown may require diagnostics beyond this testing. If, on neurologic examination, focal or lateralized (asymmetrical) signs of brain dysfunction, such as head tilt or unilateral circling, or cranial nerve deficits are identified or there are new-onset epileptic seizures, an alternate or additional cause of the behaviors is likely. In these cases, an MRI and CSF analysis should be strongly considered and offered to clients prior to establishing a presumptive diagnosis of CCDS. Neurologic examination in dogs with mild CCDS is likely normal, but in moderate to severe CCDS, findings might include bidirectional pacing, difficulty negotiating obstacles in the room (eg, getting stuck in corners), and difficulty engaging with the examiner or others in the room. Cranial nerve examination and postural reaction testing should be normal, but exaggerated startle responses might occur.

 Importantly, identification of an alternate medical condition does not exclude CCDS as a diagnosis; however, medical conditions must be managed to evaluate their contribution to the clinical signs observed.

Caregiver Surveys

Caregiver-completed questionnaires have been developed with the goal of detecting and monitoring the progression of clinical signs of CCDS.15 While some questionnaires have designated scoring criteria to identify stages of CCDS, these are not stand-alone diagnostic tools, and the monitoring of an individual’s score over time is likely more revealing than the absolute score. Further, all questions must be evaluated for change from a dog’s normal behavior; for example, house soiling as a clinical sign of CCDS is only useful if the dog was previously fully housetrained. When used consistently and completed by the same caregiver over time, questionnaires allow identification of changes in one or more of the behavioral domains indicative of CCDS.

While several questionnaires have been developed, recent studies indicate that the DISHAA questionnaire is used most commonly in primary practice.16,17 Other scales used in clinical trials and research settings include the Canine Dementia Scale (CADES) and Canine Cognitive Dysfunction Rating scale (CCDR).10,18 These scales ask caregivers to rate the frequency or severity of their dog’s behavior across multiple domains commonly affected by CCDS; scoring of the questions generates total scores that can be tracked over time. Studies comparing CCDS questionnaires report that CADES is more sensitive to mild changes, while CCDR is less susceptible to placebo effect and remains more stable over time.11,19,20 While CADES and CCDR have been included in several research studies, the wide use of the DISHAA questionnaire by primary veterinarians makes it our recommended scale for clinical use (Supplementary Material S1). Furthermore, we believe that assessing and monitoring all 6 behavioral domains associated with CCDS as encompassed by the DISHAA tool is clinically valuable (anxiety, sleep, and/or activity levels are not fully addressed in CADES or CCDR). The DISHAA questionnaire may be completed by the caregiver prior to or during their appointment, with total scores tracked over time. When possible, a single caregiver should be designated to complete the questionnaire each time for consistency in response.

Advanced Imaging With MRI

Brain imaging is a pivotal component of establishing a diagnosis in brain disease. Disorders such as cerebral infarction, brain tumor, and encephalitis cause alterations in anatomy and tissue chemistry that are detectable by MRI. In contrast, neurodegenerative diseases are associated with progressive loss of brain parenchyma, which is more difficult to detect and differentiate from normal age-related changes. As such, the role of MRI in dogs displaying cognitive decline is as much to rule out other conditions as to attempt to establish a diagnosis of CCDS.

The MRI changes observed in CCDS overlap with those observed in the healthy aging brain, with both reflecting variable degrees of neuronal loss, dendritic degeneration, demyelination, small vessel disease, and white matter pathology. Studies to date suggest these changes are more severe in dogs with CCDS.21–23

Brain atrophy

Brain atrophy is the most significant alteration observed on MRI of dogs with CCDS.21 This condition manifests as reduction in cortical volume and enlargement of the CSF-filled space, which can be documented objectively through measurement of the interthalamic adhesion (ITA) and hippocampus.22–24 Although cerebral atrophy occurs with healthy aging as well as other neurodegenerative conditions,25 its detection on MRI combined with a presenting history and clinical signs consistent with CCDS increases the confidence of an antemortem diagnosis of CCDS.

 In the clinical setting, ITA and hippocampal height can be measured from high-quality sequences acquired in a standard brain MRI protocol.22,23,26,27 However, inclusion of high-resolution T1-weighted isovolumetric 3-D sequences (magnetization-prepared rapid gradient echo [MPRAGE] or brain volume [BRAVO]), which permit standardized multiplanar reconstructions, optimizing hippocampal visualization and measurement accuracy, is recommended for aging dogs.

Three-dimensional isovolumetric T1-weighted brain volume sequence of a clinically and neurologically normal 4-year-old Beagle, with sagittal (A), transverse (B), and dorsal views (C) displayed. A 3-plane multiplanar reconstruction allows for an optimized and standardized transection of the interthalamic adhesion in sagittal plane. The interthalamic adhesion height measurement is demonstrated in yellow, and the cranial height extending from the floor to the ceiling of the calvarium is demonstrated in red. 

Citation: Journal of the American Veterinary Medical Association 2026; 10.2460/javma.25.10.0668

Interthalamic adhesion height is affected by age, body size, breed, measurement plane, and imaging sequence; expressing it as a ratio to cranial height controls for body size and breed.26 Several studies have published findings for canine ITA height and report that ITA heights of < 5.0 mm are consistent with cerebral atrophy and are associated with clinical signs of cognitive decline.22,23 However, methodology was inconsistent and established normal ranges for dogs of different ages and breeds are lacking. The sensitivity, specificity, and accuracy of this measurement remain undetermined, particularly at different ages and disease stages, and normalizing to body size is likely necessary.

We suggest that measurements should be performed on the midsagittal plane slice where ITA margins are visible, surrounded by the third ventricle. This measurement can be performed with the use of a T2-weighted sequence, but an MPRAGE or BRAVO sequence should be used, when available, to optimize measurement at the maximum ITA diameter (Figure 1). Cranial height should be measured on the axial image at the same level to normalize to body size.

Hippocampal height decreases with age, and hippocampal volume is reduced in dogs with CCDS when compared with aged controls24,26,28; however, normal ranges need to be established. Although challenging on 2-D sequences, accurate and reproducible linear measurements of hippocampal height are described.26

Cerebral microbleeds

Vascular disease is well described in the aging canine brain and associated with cerebral amyloid angiopathy.29 On MRI, vascular disease can be observed as discrete microbleeds created by small collections of blood or blood products within the brain parenchyma and associated with small vessel pathology.30,31 These blood products create a focal disruption of the magnetic susceptibility within the tissue that is detectable on susceptibility-weighted and T2* gradient echo MRI sequences; one of these sequences should be included when imaging senior dogs. Lesions are observed as small, well-defined, rounded intraparenchymal signal voids. They are primarily located within the telencephalon, although they can be observed in the deeper gray and white matter structures of the brain.30 An increase in the number of cerebral microbleeds within the brain is described in geriatric dogs, both with and without signs of CCDS, and the intersection of cerebrovascular disease and CCDS is poorly understood.31

White matter pathology

Leukoaraiosis is described on MRIs of the geriatric canine population. It is observed as bilaterally symmetrical T2-weighted and FLAIR hyperintense white matter lesions. The etiology of these lesions is unclear although hypothesized to be due to cerebral small vessel disease. Their relationship to the diagnosis of CCDS has yet to be explored.32 The presence of more extensive age-associated white matter changes throughout the major white matter tracts of the canine cerebrum has been confirmed with the use of diffusion tensor weighted imaging, but currently these sequences are not routinely acquired in clinical canine brain MRI studies.33

Cerebrospinal fluid

Cerebrospinal fluid sampling is performed under anesthesia following an MRI with the goal of eliminating alternate diagnoses. A CSF sample is typically obtained from the cerebellomedullary cistern, and analysis includes measurement of protein concentration, a red and nucleated cell count, and cytological description. In dogs with CCDS, CSF analysis should be unremarkable. Measurement of biomarkers such as neurofilament and β-amyloid (Aβ) 42 can be performed on a research basis,34,35 but standard testing methods and normal ranges have not been established. Evidence of inflammation (elevated WBC count and protein concentration) or the presence of neoplastic cells or infectious organisms would support an alternate diagnosis.

Histopathology

The histopathological criteria to establish a diagnosis of CCDS have not been described and will require the establishment of the spectrum of normal age-related changes in cognitively successful agers, as well as an array of special staining and immunohistochemistry to highlight the full extent of the pathology.5 The neuropathological alterations in CCDS encompass a spectrum of structural, cellular, and molecular changes, reflecting a multifactorial disease process that disrupts neuronal function, network connectivity, and cognitive integrity. One of the most prominent neuropathological features in CCDS is cortical atrophy, particularly in the prefrontal and temporal lobes, which is accompanied by ventricular enlargement.21 In parallel, hippocampal neuron loss is frequently observed. However, these features are nonspecific with respect to the underlying pathological etiology.

Examination of postmortem brain tissue from aged dogs with and without CCDS has revealed Aβ plaques in the brain parenchyma, notably within the cortex and hippocampus, similar to those observed in human AD brains.36,37 Current literature suggests that Aβ accumulates progressively with age in dogs, both as extracellular plaques and soluble oligomers, mirroring AD-like pathology with changes in amyloid precursor protein processing that favors amyloidogenic cleavage.38 In dogs, these plaques are predominantly diffuse and less fibrillar compared to the dense-core neuritic plaques typical of advanced human AD. While Aβ deposition is a well-documented hallmark of canine brain aging, its association with cognitive impairment is debated.37

In AD, neurofibrillary tangles, consisting of hyperphosphorylated tau (pTau), are a defining pathological hallmark and strongly correlate with disease progression and neuronal dysfunction. The role of pTau and neurofibrillary tangles in CCDS remains unclear due to conflicting findings ranging from minimal to widespread pathology. This discrepancy may be explained by technical limitations, early-stage disease processes, or alternative mechanisms underlying neurodegeneration in dogs.21,39,40 Other important histopathological changes include myelin loss, particularly in the corpus callosum and frontal lobes, neuroinflammation with activated microglia and astrocytes, evidence of oxidative damage, and cerebral amyloid angiopathy.21,29,37

Future Direction

Cognitive testing

Although hands-on cognitive testing in dogs is challenging, it remains a critical diagnostic modality, highlighting the need for simple, robust protocols that can be implemented in routine clinical settings. Laboratory paradigms to assess learning, executive function, selective attention, and working memory are informative and sensitive to changes in early aging, but require weeks of training and specialized settings, making them impractical for companion dogs.6 Batteries of cognitive tests have been developed for use in companion dogs in both home41 and controlled clinical or laboratory settings.2,42–44 Despite these advances in test paradigms, cognitive testing is not yet feasible in everyday practice. Current methods are inconsistent, time intensive, confounded by practice or floor or ceiling effects, and lack benchmarks for healthy aging. Establishing large normative datasets across age groups, breeds, and health statuses and validating test performance both cross-sectionally and longitudinally against biomarkers and pathology will be essential for making CCDS assessment clinically practical and impactful.

Blood and CSF biomarkers

Development of blood, urine, or CSF tests that can be used to diagnose and monitor neurodegenerative diseases has long been a priority in human medicine. The ideal test should be sensitive and specific, noninvasive, readily available, and affordable, but a more realistic expectation is that biomarkers will provide additional evidence to support or refute a diagnosis and monitor disease progression. In recent years, blood and CSF tests have been developed to detect Aβ and pTau, increasing the certainty of AD diagnosis and staging.4

Measurement of canine CSF and plasma concentrations of neurofilament light chain (NfL) with the use of ultrasensitive techniques has shown increased levels with age and disease status.34,45,46 While NfL is a nonspecific marker of neuronal injury, not a diagnostic test, monitoring its plasma concentrations could be a practical means of longitudinal measurement. However, more data are needed on the influence of body weight and renal and nervous system disease burden before it is clinically useful. Measurement of CSF or plasma Aβ 40 and 42 concentrations and ratios potentially offer greater specificity, although concentrations are elevated in dogs with epilepsy and reference ranges have not been established.35,47,48 Reliable tests for canine pTau are still needed. Emerging studies of aging dogs report data on diverse biomarkers for CCDS, but further validation of their accuracy and reliability is needed.49,50 Currently, while measurement of NfL and Aβ 40 and 42 is feasible, there are not enough data to support their utility as clinical biomarkers for the development of clinical guidelines.

Recommendations

When a patient presents with age-associated behavioral changes, there is a progression of diagnostic steps and criteria that need to be met. These are presented in Figure 2 and summarized herein.

Flow chart depicting diagnostic approach to dogs exhibiting changes in 6 behavioral domains (disorientation; impaired social interactions; sleep disturbances; house soiling, learning, and memory deficits; activity changes; and increased anxiety and fear [DISHAA]), identified either through routine screening or as a presenting problem. Examples of canine cognitive dysfunction syndrome (CCDS) surveys include DISHAA, the Canine Cognitive Dysfunction Rating scale (CCDR), and the Canine Dementia Scale (CADES). Routine screening should be performed every 6 to 12 months from the age of 7 years onward to establish a behavioral baseline and ensure early recognition of changes across the 6 behavioral domains. BP = Blood pressure. Chem = Serum chemistry panel. NE = Neurologic examination. PE = Physical examination. UA = Urinalysis.

Citation: Journal of the American Veterinary Medical Association 2026; 10.2460/javma.25.10.0668

Core clinical monitoring criteria

Annual screening for behavioral signs of cognitive decline should start at 7 years of age. To increase compliance, this screening can be achieved by having caregivers complete a short senior health form (Supplementary Material S2). If behavioral abnormalities are reported by the caregiver, follow-up with a CCDS scale is recommended, with ongoing monitoring every 6 months. Beginning at 10 years of age, use of a CCDS scale every 6 months is recommended for all dogs, as changes in score for an individual inform on CCDS trajectory. The DISHAA scale is recommended for ease of clinical use, but the Canine Cognitive Assessment Scale, CADES, and CCDR are alternatives. 

Core clinical diagnostic criteria to establish a diagnosis with level 1 certainty

History—Canine cognitive dysfunction syndrome is associated with slowly progressive behavioral signs reflecting cognitive impairment in an older dog, confirmed by an abnormal CCDS scale score. The history should confirm that the signs reported represent a deterioration from the dog’s previous level of function and should capture relevant environmental factors and medications. Questioning to identify possible comorbidities is critical.

Physical examination—A physical examination should be performed that includes orthopedic, neurologic, and ophthalmic examinations as well as blood pressure measurement. The goal is to identify and manage comorbidities that are contributory.

Neurologic examination—A neurologic examination should be performed to identify and localize neurologic signs. Canine cognitive dysfunction syndrome is not associated with lateralizing, focal signs, but rather diffuse signs of forebrain dysfunction. The cranial nerve examination, postural reactions, and spinal reflexes are unaffected by CCDS. Signs of CCDS identified on neurologic examination might include pacing, spatial disorientation, difficulty attracting or maintaining the dog’s attention, and exaggerated responses to tactile or threatening stimuli (eg, menace response, palpation), but the examination is likely to be normal with mild CCDS.

Minimum database—A CBC, serum chemistry panel, and urinalysis are recommended with the goal of identifying comorbidities that might result in similar behavioral changes and that could be treatable. Additional blood work and other diagnostics should be pursued as appropriate.

Core clinical diagnostic criteria to establish a diagnosis with level 2 certainty

The goal of MRI in dogs with suspected CCDS is to rule out alternate diagnoses and identify cerebral atrophy (ITA height of < 5 mm). Due to heightened clinical suspicion for an alternate diagnosis, brain MRI should be pursued whenever neurologic signs are lateralized or localized to a focal region of the brain or when there is presentation of new epileptic seizures. Establishing normal ITA-to-brain height ratios across breeds and ages is needed to determine pathological thresholds.Cerebrospinal fluid analysis parameters should be within normal limits.

https://avmajournals.avma.org/view/journals/javma/aop/javma.25.10.0668/javma.25.10.0668.xml

AVMA News I Monthly chewable tablet for screwworm in dogs receives conditional approval

Published on December 24, 2025

The Food and Drug Administration (FDA) continues to build up veterinarians’ arsenal against New World screwworm (NWS), should it cross the U.S.-Mexico border.

On December 17, the FDA conditionally approved Credelio Quattro-CA1 (lotilaner, moxidectin, praziquantel, and pyrantel) monthly chewable tablets for the treatment of infestations of NWS (Cochliomyia hominivorax) larvae in dogs and puppies at least 8 weeks of age and weighing at least 3.3 pounds.

Credelio Quattro-CA1 received expedited review through the priority zoonotic animal drug designation, as provided under the Coronavirus Aid, Relief, and Economic Security (CARES) Act. (Courtesy of Elanco Animal Health)

This comes after recent emergency use authorizations for two animal drugs for NWS: Credelio and Credelio Cat for dogs and cats, respectively, and another conditional approval for Exzolt Cattle-CA1 (fluralaner) topical solution in cattle.

Screwworm’s northward migration from Central America has prompted a massive response from animal health officials, who have called for heightened vigilance from small and large animal veterinarians to ensure the parasite, declared as eradicated in 1966, does not regain a foothold in the U.S.

Credelio Quattro CA-1, available only by prescription from a licensed veterinarian, comes in five strengths of flavored chewable tablets with active ingredients by weight.

The minimum dosage is 9 mg per lb (20 mg/kg) lotilaner, 0.009 mg per lb (0.02 mg/kg) moxidectin, 2.28 mg per lb (5 mg/kg) praziquantel, and 2.28 mg per lb (5 mg/kg) pyrantel (as pamoate salt). Dogs over 100 lb should be given the appropriate combination of chewable tablets, according to the FDA.

Credelio Quattro-CA1 must be orally administered with food. The FDA says care should be taken to ensure that the dog consumes the complete dose and that if vomiting occurs within an hour after administration, readminister a new dose.

Credelio Quattro and Credelio Quattro-CA1 contain the same active ingredients at identical doses: lotilaner, moxidectin, praziquantel, and pyrantel.

Credelio Quattro, sponsored by Elanco Animal Health, is already approved for various flea-, tick-, and worm-related indications in dogs and puppies.

The conditional approval was based on a study evaluating the efficacy of lotilaner against New World screwworm, according to the company, which said a peer-reviewed study showed oral administration of the antiparasitic drug at the minimum recommended dosage demonstrated 100% efficacy against NWS larvae within 24 hours of treatment in naturally infested dogs.

A single dose of Credelio Quattro-CA1 is “reasonably expected” to treat NWS larvae present at the time of treatment, though reinfestation may occur sooner than one month, according to Elanco’s application for conditional approval. “Treatment should be used in conjunction with the mechanical removal of larvae (live and dead) remaining in the wound after treatment.”

While livestock are most commonly affected, NWS can infest all warm-blooded animals, including wildlife, pets, and even humans. Still, most dogs in the U.S. remain at low risk of contracting NWS due to their geographic location, though animals near the U.S.-Mexico border and those that travel to countries with active cases are at higher risk of exposure.

“As a veterinarian, I’d encourage pet owners to monitor for any wounds on their dogs as even a minor scratch could serve as an entry point for New World screwworm,” said Dr. Casey Locklear, parasitology lead at Elanco, in the company announcement. “I also recommend pet owners keep their dogs on year-round parasite protection like Credelio Quattro to help minimize self-inflicted scratching that could create vulnerable sites.”

https://www.avma.org/news/monthly-chewable-tablet-screwworm-dogs-receives-conditional-approval

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DVM 360 I USDA grants full approval for novel canine parvovirus therapy

Elanco’s monoclonal antibody therapy, Trutect, received a conditional license from the federal agency in 2023.

Kristen Coppock Crossley, MA

December 16, 2025

The USDA has granted full approval for a novel therapy to treat canine parvovirus (CPV), according to Elanco Animal Health. The Canine Parvovirus Monoclonal Antibody (CPMA)—now Trutect— from Elanco received a conditional license from the USDA in 2023, and the agency extended its use for passive immunity in puppies exposed to the virus, in June 2025 .

CPV is a common infectious disease in dogs around the world. Left untreated, it results in death in approximately 90% of cases. Survival rates are estimated to be 80% to 90% in cases with aggressive treatment.2

According to data compiled by Elanco, 93% of puppies with CPV that received CPMA treatment survived. Furthermore, patients infected with the virus spent an average of 1.87 fewer days in the hospital.1

“Receiving full USDA approval of our lifesaving [parvovirus] treatment reinforces our promise to go beyond for veterinarians, pet owners, and, most importantly, the puppies across the country who need it most,” Bobby Modi, executive vice president, US pet health and global digital transformation for Elanco, said in a news release.1 “Under the brand name Trutect, our mission remains the same, to save puppies from parvovirus.”

As a nonenveloped, single-stranded DNA virus, CPV can survive for more than a year in the environment, which serves as a means of transmission. Transmission occurs through a fecal-oral route such as exposure to CPV in feces or vomit as well as fomites.3

Puppies ages 6 weeks to 6 months are more likely to develop severe illness with CPV, especially those younger than 12 weeks. CPV disease can also develop in unvaccinated or improperly vaccinated adult dogs. In some regions, distribution of CPV disease has been seasonal, while socioeconomic disadvantage was found to play a role in at least one surveillance study.3

Tannetje Crocker, DVM, an emergency veterinarian at Veterinary Emergency Group in Dallas, Texas, and owner of Alta Vista Animal Hospital in Fort Worth, said she has seen firsthand the “devastating” effect of CPV throughout her career. “Since 2023, I have proudly used CPMA and have reunited countless puppies with their families. I’ve also used the product on exposed puppies, helping to keep them protected from this highly contagious virus. I believe every [veterinary] clinic should keep [CPMA] on hand because you never know when a parvo puppy will need this targeted treatment,” Crocker said in the release.1

According to Elanco data on file, there is a 90% satisfaction rate from clinics that incorporated CPMA into their treatment protocols. Additionally, 92% of veterinarians reported a reduction in overall clinic stress while using CPMA in the treatment process, and 83% expressed they would recommend it to their peers.

“The real-world data collected over the first year of CPMA availability shows that as a result of these efforts and more, survival rates for puppies battling the deadly virus improved. We also saw enhanced operational efficiency and high satisfaction within veterinary clinics–demonstrating that Trutect has already started rewriting the protocol for parvovirus treatment,” Jill Pattee, DVM, a veterinarian for Elanco Animal Health, said in the release.1

In a 2024 interview with dvm360, Crocker also recommended vaccination against CPV infection for reducing disease exposure and transmission, as well as client education. “I see a ton of dogs come in that are unvaccinated. Puppies are not fully vaccinated…So the recommendation is simple, and it’s something that I feel like people should know. But then the more I talk to pet owners, and I talk to them about what [CPV] is, they just don’t know. So we want to make sure we get the word out about how important vaccination is and knowing the early signs of [CPV],” she said in the interview.4

Common clinical signs of CPV include fever, lethargy, inappetence, vomiting, severe diarrhea, dehydration and depression. In rare cases, sudden death or tachypnea caused by myocarditis may also occur.2,3

Elanco launched a multi-year campaign in 2024 with a mission to help prevent and defeat CPV in puppies. As part of this campaign, the company introduced the first National Parvo Awareness Day to provide education about CPV. Additionally, Elanco has expanded its manufacturing facility in Elwood, Kansas, and is continuing to invest in the growth of the company’s monoclonal antibody platform.1

For pet owners with dogs exposed to or infected with CPV, Elanco is increasing availability of CPMA and offers a $200 rebate with purchase. The company has also donated more than $3 million of CPMA product across 2300 clinics and shelters throughout the US.1

References

1. Elanco announces full USDA approval of CPMA (now Trutect) the first-and-only treatment for deadly canine parvovirus. News release. Elanco. December 15, 2025. Accessed December 16, 2025. https://www.elanco.com/us/newsroom/press-releases/trutect-USDA-approval

1. What every pet owner should know about parvo-virus. Jefferson Animal Hospital Regional Emergency & Trauma Center. Accessed December 16, 2025. https://jeffersonanimalhospitals.com/what-every-pet-owner-should-know-about-parvo-virus

1. Sykes JE. Chapter 14: Canine parvovirus infections and other viral enteritides. In: Sykes JE, ed. Canine and Feline Infectious Diseases. 2013;141-151. doi:10.1016/B978-1-4377-0795-3.00014-4

1. Crossley KC. Generating awareness about parvovirus vaccination. dvm360. June 25, 2024. Accessed December 16, 2025. https://www.dvm360.com/view/generating-awareness-about-parvovirus-vaccination

https://www.dvm360.com/view/usda-grants-full-approval-for-novel-canine-parvovirus-therapy

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AVMA I Personality traits and workplace factors predict professional quality of life among companion-animal veterinary professionals 

Lindsay Nakonechny, MSc, Alissa Cisneros, MSc, Carly M. Moody, PhD, and Anastasia Chiara Stellato, PhD 

December 15, 2025

Objective

To assess the prevalence of burnout (BO), secondary traumatic stress (STS), and compassion satisfaction (CS) and identify associated individual, clinic, and dog-handling factors among veterinary professionals.

Methods

A cross-sectional online questionnaire was distributed to veterinary professionals in Canada and US (2023 to 2024). The questionnaire collected individual, clinic, and dog-handling information and measured ProQOL (BO, STS, CS). Logistic regression models examined associations between these factors and ProQOL.

Results

Participants (n = 691) had moderate BO (71.2%), STS (71.8%), and CS (74.3%); 2.4% reported high STS, and none had high BO. Veterinarians had lower odds of moderate/high BO (OR, 0.50; 95% CI, 0.32 to 0.78) and CS (OR, 0.12; 95% CI, 0.021 to 0.64) compared with nonveterinarians. Below-normal personality traits were associated with moderate/high BO and/or STS: extraversion (BO: OR, 2.25; 95% CI, 1.47 to 3.46), agreeableness (BO: OR, 2.02; 95% CI, 1.29 to 3.18; STS: OR, 1.60; 95% CI, 1.07 to 2.39), conscientiousness (BO: OR, 3.91; 95% CI, 2.41 to 6.34; STS: OR, 3.81; 95% CI, 2.47 to 5.88), emotional stability (BO: OR, 1.96; 95% CI, 1.24 to 3.11), and openness (BO: OR, 1.64; 95% CI, 1.05 to 2.56; STS: OR, 1.88; 95% CI, 1.26 to 2.81). Stress-reducing certification was associated with moderate/high BO (OR, 2.04; 95% CI, 1.14 to 3.64).

Conclusions

Personality traits and individual factors were associated with ProQOL, whereas handling techniques were not.

Clinical Relevance

Findings provide exploratory evidence for workplace strategies to reduce BO and STS and enhance CS while generating hypotheses for future intervention research.

Veterinary professionals work under emotionally and physically demanding conditions that can adversely affect their professional quality of life (ProQOL) or how individuals feel in relation to their work as a helper.1 There are both positive and negative aspects of helping others that affect an individual’s ProQOL, including compassion fatigue (CF) and compassion satisfaction (CS).1 Compassion fatigue refers to the adverse consequences of helping others and is further broken down into burnout (BO) and secondary traumatic stress (STS).1 Burnout arises from cumulative high workloads and stressors and includes feelings of overwhelm, inefficacy, and physical and mental exhaustion.1 Secondary traumatic stress results from direct or indirect exposure to work-related trauma (eg, animal suffering, distressed clients) and presents with symptoms such as fear, sleep disruptions, and avoiding traumatic triggers.1 In contrast, CS includes pleasurable and positive feelings derived from helping others; it is independent from CF but can help to mitigate its negative effects.1 In studies2–4 of veterinary populations, ProQOL is commonly assessed using the ProQOL-5 scale, which is a validated, 30-item self-report measure.1 High levels of BO and STS have been reported among veterinarians of all practice types in the US and Canada, with 41% to 50% and 59% to 69% of respondents classified as having high BO and STS, respectively.2–4 Globally, studies report that 40% to 74% of veterinary populations have moderate scores of CS, including samples of nonveterinarians and veterinarians5–6 and veterinarians only.3,4,7

Common occupational stressors in the veterinary industry include high job demands (eg, long work hours, work pressure, cognitive burden) and exposure to ethical conflicts, moral distress (eg, animal neglect), animal suffering, and client distress, such as performing euthanasia and/or making euthanasia-related decisions.8–10 Such stressors have been identified as contributors to BO and STS in individuals who work with animals, including veterinarians and technicians.5,11–13 In veterinarians, BO has been associated with poor physical health, depression, anxiety, suicidal ideation, and suicide.10,14 Compounded by the dual responsibility to both patients and their human caregivers and client expectations, these stressors are uniquely characteristic and of pressing concern in veterinary medicine.8,9,13

Several risk factors for BO, STS, and CS have been identified in veterinary populations, including staff role, practice type, and individual characteristics. Differences in role (ie, veterinarians vs nonveterinarians) have been linked to variations in ProQOL. For example, technicians have been found to have higher BO compared to veterinarians.13,15,16 However, other research has not identified differences in BO or STS between these roles.11 Practice type may also impact ProQOL as emergency veterinary medicine is associated with unique stressors, such as shift work, critical cases, and increased exposure to patient death and distressed clients,17,18 potentially increasing risks of BO and STS compared to general practice. Individual characteristics may further shape ProQOL as younger veterinary staff, females, and recent graduates have been reported to be at a higher risk of BO and STS.13,19–21 Further, personality may influence how individuals experience and respond to occupational stress and risk of BO.22 Personality refers to consistent patterns of feelings and behaviors among individuals and is commonly assessed using the 5-factor model of personality traits, or the “Big Five,” which is comprised of 5 personality traits: extraversion, agreeableness, conscientiousness, emotional stability, and openness.23 Research in human healthcare has linked certain Big Five personality traits, particularly higher neuroticism and lower emotional stability, to an increased risk of BO in physicians.24

Beyond these individual and clinic-level influences on ProQOL, interactions with patients may also shape veterinary professionals’ ProQOL. Handling animals that are fearful and/or show aggression can be especially stressful for handlers as staff must manage the immediate risk of injury, often in fast-paced or unpredictable situations. Dog bite and scratch injuries are consistently among the most frequently reported occupational hazards for veterinary staff globally and across practice types.25 Using passive or minimal restraint (ie, holding the dog’s shoulders, allowing some movement of the body and limbs) is recommended26 as it has been associated with fewer signs of fear in dogs during routine examinations in some experimental studies.27,28 Reduced dog fear may enhance the safety of veterinary staff as a North American survey study29 reported lower patient-related injury rates among small-animal clinics where all staff were certified in stress-reducing practices compared to clinics with some or no certified staff. The use of minimal restraint may be associated with lower BO and STS and/or higher CS in veterinary staff due to its potential to reduce dog fear and aggression during examinations,27,28 support positive dog-human interactions,26 and reduce patient-related injuries.26,29

To date, research in the US and Canada has primarily focused on risk factors for ProQOL among veterinarians of all practice types, with comparatively less attention given to the broader veterinary team, including technicians and other support staff. Furthermore, there has been limited exploration of the factors that contribute to CS. The aim of this study was to estimate the prevalence of BO, STS, and CS and to identify predictors of ProQOL among veterinary professionals in Canada and the US who routinely handle dog patients. We hypothesized that ProQOL scores would be associated with (1) individual factors (eg, demographics, personality traits), (2) clinic-level factors (eg, staff role, practice type), and (3) restraint techniques used (minimal vs full-body restraint).

Methods

This cross-sectional study was reviewed and approved by the Texas Tech University Research Ethics Board (No. IRB2023-462) for research involving human participants.

Data collection

An online cross-sectional questionnaire was distributed to veterinary professionals who handle dogs routinely across Canada and the US. The questionnaire was originally developed for a previous study30 using the same dataset; full methodological details are available in Nakonechny et al.30 Briefly, eligible participants were 18 years of age or older, resided in Canada or the US, and worked as a licensed veterinarian, veterinary technician, or assistant (either licensed or unlicensed) who handles dogs during routine health examinations. Participants were recruited using convenience snowball sampling via advertisements on social media platforms, including Facebook and Instagram. Email invitations were also sent to veterinary organizations in both eligible countries (eg, Canadian Veterinary Medical Associations and AVMA) to distribute to their members for further recruitment. Data collection occurred from October 2023 through February 2024. Participation was voluntary and anonymous, with informed consent obtained prior to survey access. The completion time averaged approximately 15 minutes. To minimize social desirability bias, no identifying information was collected or linked to participant responses, and participants were informed of such anonymity. We estimated the minimum sample size as 550 responses based on a conservative event-per-variable value of 30 with approximately 15 explanatory variables, and after inflating the sample size by approximately 30% to account for a low response rate,31 we estimated a sample of 700 responses. To verify external validity, we also considered the size of the target population. Using the target population of companion-animal veterinarians (US, approx 71,693; Canada, approx 11,885) and veterinary technicians and assistants in US and Canada (US, approx 122,000; Canada, approx 15,300), the required sample at 95% confidence and a 5% margin of error was estimated to be approximately 400.32–34

Questionnaire

The online questionnaire was created using Qualtrics survey software (Qualtrics LLC). The questionnaire was comprised of 26 questions, categorized into 5 sections: (1) participant and clinic information, (2) participant ProQOL (using the ProQOL-5 scale), (3) general examination practices, (4) perceived factors affecting dog handling during examinations, and (5) frequency of using 14 dog-handling techniques and tools. This analysis focused exclusively on data from sections 1 and 2. Variables from section 5 were included only as explanatory factors in the current models, whereas data from sections 3 through 5 are examined in detail in a separate analysis in Nakonechny et al,30 where the full questionnaire is also provided.

Statistical analysis

All analyses were performed with Stata statistical software, version 15.1 (StataCorp).

Data management

Professional quality of life was assessed using the ProQOL-5 scale, which provides 3 subscale scores: BO, STS, and CS. This validated self-report tool is widely used in research to assess the beneficial and detrimental impacts of helping professions, including veterinary professionals.2–7,11,12 Each subscale contains 10 items rated on a 5-point Likert scale (1 = never to 5 = very often), generating total scores from 10 to 50. Scores were categorized using established thresholds into low (< 23), moderate (23 to 41), and high (> 41) ranges.1 Personality traits were evaluated with the Ten Item Personality Inventory (TIPI), a brief 10-item measure of the Big Five domains: extraversion, agreeableness, conscientiousness, emotional stability, and openness.23 Each trait is represented by 2 items, with responses rated on a 7-point scale, ranging from 1 (strongly disagree) to 7 (strongly agree).23 Handling practices were examined by asking participants to report on a Likert scale how often they used 14 specific dog-handling techniques with small (< 35 lb) and large (≥ 35 lb) dogs under 3 behavioral states (calm, fearful, aggressive). The list of techniques, accompanied by written descriptions and photographs, was adapted from Carroll et al35 and is provided in the questionnaire documented in Nakonechny et al.30

To appropriately conduct logistic regression models, our outcome variables (BO, STS, and CS) were consolidated to create a binary outcome with 2 levels, “high” (moderate, high; ≥ 23) and “low” (low; < 23). Given the distribution of ProQOL scores, in which the majority of participants reported moderate scores and relatively few to no participants reported scores at the high or low cutoffs, all subscale outcome variables were dichotomized to “low” (range cut point, < 23) and “moderate/high” (range cut point, moderate: 23 to 50) categories based on established cut points (range cut point).1 This approach was chosen to address the non-normal distribution of the data and enable the use of logistic regression, which does not assume normality of the outcome variable. Further, it helped to consolidate categories with sparse count responses (eg, high BO and STS) to improve model stability and interpretability of results while maintaining alignment with established ProQOL cut points. Given the distribution of the data, binary categorization was deemed most appropriate given the data distribution.

A total of 19 explanatory variables were used for analysis, encompassing 13 variables related to participant demographics and clinic characteristics and 6 variables describing handling practices of calm, fearful, and aggressive dogs. To reduce the total variables tested for analysis, conceptually similar items were combined into composite variables. For example, the category “nonveterinarian” was generated by grouping licensed veterinary technicians, nonlicensed veterinary technicians, and veterinary assistants as these roles originated from the same survey item on staff position and were closely related in meaning. Reference categories for categorical predictors were selected either based on the most common response or biological plausibility. For example, in analyses of staff role, nonveterinarians were used as the referent group since they represented the larger proportion of respondents. Data cleaning included review of responses to “other” options, which were crosschecked against existing categories to reduce misclassification bias. Categories with limited conceptual relevance or < 5 responses were collapsed with similar categories or excluded to prevent overfitting. For instance, participants who selected “other” for practice type but whose responses did not align with established categories (small animal practice, mixed animal practice, or emergency clinic) were removed from analyses. Suspicious responses that suggested automated submissions, such as unusually rapid completion times (< 5 minutes) or nonsensical open-text answers, were also excluded.36,37

Risk factor analysis

Logistic regression models were developed to assess the impact of the explanatory variables on the following outcomes: (1) CS score, (2) BO score, and (3) STS score. Explanatory variables were related to individual and clinic factors: country, gender, age, graduation year, TIPI of the Big Five personality traits (extraversion, agreeableness, conscientiousness, emotional stability, openness), staff role (veterinarian, nonveterinarian), practice type (small animal, mixed animal, emergency clinic), dog bite history, and stress-reducing certification (eg, Fear Free Certified Veterinary Professional). Additionally, 3 separate logistic regression models were conducted to assess whether the frequency of using minimal or full-body restraint when handling calm, fearful, and aggressive dogs influenced the outcome variables (BO, STS, CS scores). Two restraint techniques were selected for analysis: minimal restraint, representing a low level of physical restraint, and full-body restraint, reflecting a high degree of physical control and recognized as aversive for dogs.26,27 These techniques were chosen because they reflect contrasting levels of physical restraint. To facilitate interpretation, responses regarding frequency of use were recoded into a binary variable with 2 categories: “used” (always, often, and sometimes) and “not used” (rarely and never). This variable was based on handling practices with large dogs across all behavioral demeanors, as in a previous study30 using the same questionnaire and participant data, there were no meaningful differences in restraint frequency observed between small and large dogs.

Relationships between continuous predictors (TIPI scores) and outcomes (CS, BO, STS) were examined using locally weighted regression curves and by testing quadratic terms.31 These associations were neither linear nor quadratic, and log transformations did not improve model fit. As a result, continuous variables were categorized. Following Gosling et al,23 TIPI scores were classified as below or above population norms (extraversion, 4.44; agreeableness, 3.23; conscientiousness, 5.40; emotional stability, 4.83; openness, 5.38). Correlation testing among explanatory variables showed that none exceeded a coefficient of 0.70, reducing multicollinearity concerns.

Univariate analyses were conducted to evaluate each independent variable’s association with the 3 ProQOL outcomes (CS, BO, STS). Variables with a liberal significance threshold of P ≤ .20 were retained for multivariable modeling to ensure that potentially meaningful factors were retained.31 Multivariable models were then constructed using a manual stepwise approach, with only predictors meeting P < .05 kept in the final models. Potential confounders were identified using biological and clinical plausibility based on prior research.31 A covariate was considered a confounder if its inclusion altered another variable’s coefficient by more than 30%,31 a conservative cutoff to identify influential covariates. To improve model parsimony, only interactions that were both biologically relevant and reduced the Bayesian information criterion were retained. Model fit was evaluated with the Bayesian information criterion, with a lower value preferred. Results were expressed as ORs with 95% CIs. Odds ratio values above 1 indicated greater odds (potentially risk enhancing), whereas values below 1 indicated lower odds (potentially protective). Given the cross-sectional design, risk factors generated from these models are reported as statistical associations with BO, STS, and CS without implying causality or temporal direction.

Results

Participants

In total, 920 responses were submitted. After excluding 229 suspected automated responses (identified using recommended screening methods)37 and individuals who did not meet eligibility requirements, 691 responses remained for analysis. As several questionnaire fields were optional, the number of respondents differs across variables. The majority of participants were located in the US (541 of 691 [78.3%]), identified as female (429 of 690 [62.2%]), and were between 25 and 44 years of age (531 of 686 [77.4%]). With respect to staff role, 454 of 671 (67.7%) were nonveterinarians (technicians and assistants), and 217 of 671 (32.3%) were veterinarians. Participants worked primarily in general small-animal practice (361 of 689 [52.4%]), followed by mixed-animal practice (209 of 689 [30.3%]), emergency clinics (105 of 689 [15.2%]), and other settings, such as shelter medicine (14 of 689 [2.0%]). A large proportion (544 of 626 [86.9%]) reported holding at least 1 stress-reducing certification, including Fear Free Certified Veterinary Professional, Sophia Yin Low Stress Handling Silver Certification, or Karen Pryor Better Veterinary Visits. Detailed characteristics of participants are provided in Supplementary Table S1 in Nakonechny et al.30

Risk factors for BO, STS, and CS

All 5 personality traits (extraversion, agreeableness, conscientiousness, emotional stability, and openness) were associated with BO scores; specifically, participants with below-normal scores had higher odds of moderate/high BO compared to those with above-normal scores (Table 2). Participants with a stress-reducing certification had higher odds of moderate/high BO compared to participants with no certification. Further, veterinarians had lower odds of moderate/high BO compared to nonveterinarians.

Several personality traits (agreeableness, conscientiousness, and openness) were associated with STS scores. Similar to BO, participants with below-normal scores had higher odds of moderate/high STS compared to those with above-normal scores (Table 2).

Regarding CS, veterinarians had lower odds of moderate/high CS compared to nonveterinarians (Table 2). Further, participants who were unsure of their dog bite history had higher odds of moderate/high CS compared to those with no bite history.

Several risk factors were not detected to influence ProQOL outcomes. Specifically, the frequency of using minimal or full-body restraint on calm, fearful, and aggressive dogs did not influence participants’ BO, STS, or CS scores. Participants’ country of residence was not associated with ProQOL nor were factors reported in previous literature, including gender, age, and graduation year.9,21–23

Discussion

The majority of participating veterinary professionals in this study scored within the moderate range for BO, STS, and CS. This finding is consistent with other studies5–7,11,13 assessing the prevalence of low, moderate, and high BO, STS, and CS among mixed samples of veterinarians and support staff internationally. No participants in our sample were classified as having high BO, and only a small proportion were categorized as having high STS (2.4%). In contrast, prior studies2–4 of veterinarians in Canada and the US, focusing exclusively on homogeneous samples of practicing veterinarians, have reported much higher proportions of individuals whose ProQOL scores fall within the high range for BO and STS. Thus, differences in the prevalence of low, moderate, and high ProQOL scores among various studies may be attributed to sample composition. Although most participants had moderate scores for all ProQOL subscales, the risk of moderate/high BO and CS varied between roles.

Results from regression models found that those who identified as nonveterinarians had an increased risk of moderate/high BO and CS compared to veterinarians. Previous research has reported high BO among veterinary technicians, with contributing factors including unmanageable workloads, interpersonal relationships, low reward for effort, and feeling unsupported.15,16,38,39 Though day-to-day responsibilities and job requirements differ by staff role, veterinarians have reported experiencing similar occupational stressors as veterinary technicians and assistants.8,9 Technicians may engage in frequent difficult interactions with clients and coworkers, including incivility, and are often under time constraints with limited autonomy and decision-making authority.39,40 The cumulative demands of these responsibilities, coupled with lower compensation and reward and limited support, may contribute to the higher rates of BO observed among technicians.15,16,39

Differences in job duties between veterinarians and support staff may also explain the observed variation in CS. For example, veterinarians often move from patient to patient throughout the day, focusing on diagnoses, treatment plans, and documentation,6 whereas support staff may spend more time directly engaging with patients by providing supportive care (eg, petting, feeding, monitoring patients after treatment).6 There are limited studies on CS among veterinary populations; one mixed-methods study41 of Canadian veterinarians and technicians found that interacting with, helping, and developing relationships with patients and clients were highly satisfying aspects of their work and were positively associated with CS. Although negative interactions with clients may contribute to BO, positive interactions may also enhance CS for support staff.41 Given the limited research and observed variation in ProQOL across staff roles, further investigation is needed to inform the development of role-specific interventions and workplace practices that reduce BO and support CS.

Participants with a stress-reducing certification were more likely to have moderate/high BO. Other survey studies42,43 have found that veterinary professionals often encounter barriers to using stress-reducing practices, such as high caseloads and time pressures, unsupportive workplace cultures, and limited colleague understanding of these approaches. These individuals possess the knowledge about how to reduce dog fear during routine care but may be prevented from doing so due to various constraints, potentially resulting in moral conflicts leading to distress, as they cannot pursue actions they perceive to be ethically correct.44 One such constraint may be the clinic culture and environment not being conducive for stress-reducing practices. For example, we hypothesize that individuals who work at clinics where all staff involved with animal handling are certified and/or have positive attitudes toward stress-reducing practices may experience fewer barriers and, subsequently, less BO and/or higher CS. Future research is warranted to clarify the relationship between stress-reducing certification and staff ProQOL.

Personality traits were found to influence both BO and STS. Lower emotional stability and extraversion scores were associated with higher BO. This is consistent with prior research, where individuals with greater difficulty managing negative emotions (lower emotional stability) or less tendencies to seek out social interactions (lower extraversion) may be more vulnerable to emotional exhaustion.45 Prior research in veterinary and human healthcare also links neuroticism, conceptually similar to low emotional stability, with increased stress and BO.13,45 Below-normal scores of agreeableness, conscientiousness, and openness were associated with higher STS. Individuals with low agreeableness and/or openness may be less inclined to seek help from others, such as mental health professionals, or lack supportive relationships.1,46 Low levels of conscientiousness have been associated with decreased coping abilities and increased susceptibility to stress.47 Several personality traits associated with STS were also predictive of BO (agreeableness, conscientiousness, and openness), suggesting possible comorbidity between these constructs. Below-normal Big Five personality scores may also reflect a mismatch between staff characteristics and the traits that clients and colleagues tend to value, specifically higher agreeableness, conscientiousness, and extraversion in veterinary professionals.48 This mismatch could increase the likelihood of stress due to interpersonal conflicts between veterinary staff and clients, thereby exacerbating the risk of BO. However, this relationship is speculative and likely not straightforward. For instance, Perret et al49 found that poor veterinarian mental health measures (eg, high perceived stress) were associated with higher client satisfaction. Assessing personality traits may provide insights into individuals’ susceptibility to occupational stress and their ability to cope effectively. Future studies should clarify these associations, which could inform tailored preventive or intervention approaches to lessen BO and STS.

Several tested predictors of ProQOL were not statistically associated but remain important to consider. Notably, there were no detected associations between the use of minimal or full-body restraint and BO, STS, or CS, suggesting that handling practices alone may not influence ProQOL. It is possible that the use of full-body restraint is common enough in clinical settings that it is not perceived as stressful or problematic by participants or that handling techniques are associated with more transient effects (eg, acute stress, changes in mood) that are not captured by constructs like BO, STS, or CS. Other stress-reducing strategies (eg, providing treats, use of counterconditioning and/or desensitization) may have a greater impact on staff ProQOL than the handling techniques assessed. Data from a related analysis using the same survey and participant population revealed that individuals with low to moderate STS were more likely to apply full-body restraint on fearful dogs, compared to those with high STS.30 This suggests that STS may influence handling practices, but the routine use of these handling techniques does not influence STS or other ProQOL subscales in this context. It is possible that the effects of handling-related stress on ProQOL are moderated by other unexplored factors, such as perceived control, resilience, and training or previous experiences. Additionally, the approach in dichotomizing handling frequency may have limited our ability to detect subtle effects.

Furthermore, individual factors, such as gender, age, and graduation year, reported in previous studies13,19–21 as risk factors for poor veterinary ProQOL (eg, high BO and STS), were not detected as risk factors. This is possibly due to the sample composition (eg, low variability in ProQOL scores). These findings highlight the complexity of factors influencing ProQOL and suggest that predictors are likely context and sample dependent. Future research should examine individual, clinic, and handling-related factors using larger, more diverse samples and observational designs to better capture their potential impact on staff ProQOL.

This study has several limitations, primarily related to potential biases. The use of convenience and snowball sampling through email and social media may have introduced voluntary response bias, likely favoring younger individuals, those comfortable with online platforms, and participants with a stronger interest in stress-reducing practices. Nonresponse bias or a healthy worker effect is also possible as most respondents reported moderate ProQOL scores, whereas national surveys estimate that approximately 18% of US veterinarians experience high or very high BO.13 This suggests that professionals with high BO and/or STS may have been underrepresented in our sample. Nonetheless, the demographic composition of our respondents, predominantly female, younger or recent graduates, and working in small-animal practice, reflects the general profile of veterinary professionals in North America.32–34 Further, given the broad inclusion criteria, it is possible that veterinary staff outside of clinical veterinary practice, such as animal laboratory staff, may have participated in the study; however, no participants self-identified as laboratory animal staff (ie, in the “other” category).

Several methodological and analytic limitations should be considered when interpreting these findings. Veterinary technicians and assistants were grouped together (into nonveterinarians) to allow ease of comparison to veterinarians. Despite some overlap in responsibilities between technicians and assistants (eg, performing dog handling/restraint during examinations), these roles have different education requirements, skill sets, and scopes of duties. Future studies should examine these roles separately to identify role-specific risk factors.

Certain individual predictors identified in other research (eg, gender, age, early career status) were not detected in our models, potentially due to limited variability within our sample. Further, dichotomizing ProQOL scores simplified interpretation and improved model stability given the sparse data in high BO and STS categories; however, this likely reduced sensitivity to subtle differences in subscale scores within the moderate to high range. Wide CIs for some associations also suggest imprecision, likely attributable to low event counts for some variables. Further, testing multiple predictors across 3 regression models may increase the chance of a type I error; thus, findings should be considered exploratory and hypothesis generating. There were also some findings that were difficult to interpret and warrant further investigation. For example, participants who reported an unknown bite history had higher odds of moderate/high CS (compared to reporting no bite history); the mechanism underlying this association is unclear. Further, the cross-sectional design of this study also limits the ability to infer causality between explanatory variables and ProQOL.

Despite these limitations, this study contributes novel insights into the ProQOL of veterinary professionals who routinely handle dogs. Most participants reported moderate levels of BO, STS, and CS. Individual factors, including staff role, stress-reducing certification, and certain personality traits, were associated with ProQOL, but handling techniques were not. Notably, Big Five traits were linked to BO and STS but not CS, suggesting that distinct factors may underlie protective versus risk outcomes. Understanding predictors of both positive and negative aspects of ProQOL is essential for guiding targeted, evidence-based interventions. Future research should incorporate broader measures, such as empathy and resilience; use mixed-methods approaches to capture complexity at individual and clinic levels; and validate these findings across more diverse veterinary populations.

https://avmajournals.avma.org/view/journals/ajvr/aop/ajvr.25.10.0355/ajvr.25.10.0355.xml

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FDA  Approves Renewal of Canalevia-CA1, Jaguar Health’s Drug for Chemotherapy-Induced Diarrhea (CID) in Dogs

December 10,  2025

Topic: Company Update

Conditional approval extended through December 2026 for the treatment of CID in dogs

CID confirmatory effectiveness trial expected to conclude in February 2026, ahead of FDA’s June deadline – 51 dogs enrolled to date; ~49 more expected

SAN FRANCISCO, CA / ACCESS Newswire / December 10, 2025 / Jaguar Health, Inc. (NASDAQ:JAGX) today announced that the U.S. Food and Drug Administration (FDA) has granted renewal of the conditional approval for Canalevia-CA1  (crofelemer delayed-release tablets). Canalevia-CA1, the company’s prescription drug for the treatment of chemotherapy-induced diarrhea (CID) in dogs, is available from multiple leading veterinary distributors in the U.S., including Chewy. The renewal of conditional approval is in effect until December 21, 2026.

“Canalevia-CA1 is an important prescription drug for the veterinary community and the thousands of dogs experiencing CID. We’re very pleased about this conditional approval renewal, which, per FDA regulations, is for the fifth and final allowable year of conditional approval for Canalevia-CA1 for the CID indication in dogs. When an animal drug receives conditional approval, the FDA requires that a confirmatory trial take place within 5 years to provide the substantial evidence of effectiveness required for full approval of the drug for the indication,” said Dr. Michael Guy, D.V.M., M.S., Ph.D., Jaguar’s Vice President of Preclinical and Nonclinical Studies. “As announced, our full effectiveness study of Canalevia-CA1 for the treatment of CID in dogs is underway, and this recent conditional approval renewal was granted because we were able to demonstrate active progress toward generating this required data.”

“Diarrhea is a highly neglected and unmet medical need in dogs and people undergoing cancer treatment,” said Lisa Conte, Jaguar’s president and CEO. “Jaguar is deeply committed to supporting the quality of life of people and animals undergoing cancer treatment.”

About Conditional Approval and Full Approval

Canalevia-CA1 initially received conditional approval in December 2021 from the FDA for the treatment of CID in dogs. FDA’s conditional approval allows a drug company to legally promote, advertise and sell the animal drug for the labeled uses before proving it meets the “substantial evidence” standard of effectiveness for full approval. The conditional approval is valid for one year, with up to four annual renewals, for a total of five years of conditional approval. To receive a renewal from the FDA, the company must show active progress toward proving “substantial evidence of effectiveness” for full approval. After collecting the remaining effectiveness data, the company then applies to the FDA for full approval. The FDA reviews the application and, if appropriate, fully approves the drug.

About Canalevia®-CA1

Canalevia-CA1 contains crofelemer, Jaguar’s novel, oral plant-based drug sustainably harvested from the Croton lechleri tree, that modulates chloride channels in the gastrointestinal tract to reduce diarrhea. Importantly, Canalevia is not an antibiotic drug. The overuse and misuse of antibiotics, both in humans and animals, contribute to the development of bacteria that are resistant to antibiotics. Canalevia-CA1, currently conditionally approved by the FDA under application number 141-552, is a tablet that can be given orally twice a day for up to three days and can be used for home treatment of CID in dogs.

About Chemotherapy-induced Diarrhea (CID) in Dogs

According to the American Veterinary Medical Association, approximately 1 in 4 dogs will at some stage in their life develop cancer. Nearly half of dogs over 10 will develop cancer.1 According to the National Cancer Institute at the National Institutes of Health, roughly 6 million new cancer diagnoses are made in dogs yearly in the US.

Due to the increasing number of chemotherapeutic agents, chemotherapy is fast becoming the most widely used cancer treatment in veterinary medicine. Studies have found the incidence of CID to be one of the three most prevalent side effects in dogs undergoing cancer treatment,2 and managing side-effects such as diarrhea can be important to maintain successful cancer treatment. More than half of the US veterinarians who responded to a Jaguar-sponsored survey reported that CID interferes with their patients’ chemotherapy treatment plans, indicating an unmet need for an effective product for the treatment of CID.

Important Safety Information About Canalevia®-CA1

For oral use in dogs only. Not for use in humans. Keep Canalevia-CA1 (crofelemer delayed-release tablets) in a secure location out of reach of children and other animals. Consult a physician in case of accidental ingestion by humans. Do not use in dogs that have a known hypersensitivity to crofelemer. Prior to using Canalevia-CA1, rule out infectious etiologies of diarrhea. Canalevia-CA1 is a conditionally approved drug indicated for the treatment of chemotherapy-induced diarrhea in dogs. The most common adverse reactions included decreased appetite, decreased activity, dehydration, abdominal pain, and vomiting.

Caution: Federal law restricts this drug to use by or on the order of a licensed veterinarian. Use only as directed. It is a violation of Federal law to use this product other than as directed in the labeling. Conditionally approved by FDA pending a full demonstration of effectiveness under application number 141-552.

About the Jaguar Health Family of Companies

Jaguar Health, Inc. (Jaguar) is a commercial stage pharmaceuticals company focused on developing novel proprietary prescription medicines sustainably derived from plants from rainforest areas for people and animals with gastrointestinal distress, specifically associated with overactive bowel, which includes symptoms such as chronic debilitating diarrhea, urgency, bowel incontinence, and cramping pain. Jaguar family company Napo Pharmaceuticals (Napo) focuses on developing and commercializing human prescription pharmaceuticals for essential supportive care and management of neglected gastrointestinal symptoms across multiple complicated disease states. Jaguar family company Napo Therapeutics is an Italian corporation Jaguar established in Milan, Italy in 2021 focused on expanding crofelemer access in Europe and specifically for orphan diseases. Jaguar Animal Health is a Jaguar tradename. Magdalena Biosciences, a joint venture formed by Jaguar and Filament Health Corp. that emerged from Jaguar’s Entheogen Therapeutics Initiative (ETI), is focused on developing novel prescription medicines derived from plants for mental health indications.

For more information about:

Jaguar Health, visit https://jaguar.health

Napo Pharmaceuticals, visit napopharma.com

Napo Therapeutics, visit napotherapeutics.com

Magdalena Biosciences, visit magdalenabiosciences.com

Canalevia-CA1, visit canalevia.com

Forward-Looking Statements

Certain statements in this press release constitute “forward-looking statements.” These include statements regarding Jaguar’s expectation that the company’s ongoing trial will provide the substantial evidence of effectiveness required for full approval of the drug for treatment of CID in dogs and will conclude in February 2026 with an approximate total of 100 dogs having participated. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “aim,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplate,” “believe,” “estimate,” “predict,” “potential” or “continue” or the negative of these terms or other similar expressions. The forward-looking statements in this release are only predictions. Jaguar has based these forward-looking statements largely on its current expectations and projections about future events. These forward-looking statements speak only as of the date of this release and are subject to a number of risks, uncertainties and assumptions, some of which cannot be predicted or quantified and some of which are beyond Jaguar’s control. Except as required by applicable law, Jaguar does not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise.

1 “Cancer in Pets.” American Veterinary Medical Association, 2021, https://www.avma.org/resources/pet-owners/petcare/cancer-pets

2 Mason SL, Grant IA, Elliott J, Cripps P, Blackwood L. Gastrointestinal toxicity after vincristine or cyclophosphamide administered with or without maropitant in dogs: a prospective randomised controlled study. J Small Anim Pract. 2014;55:391-398

https://www.accessnewswire.com/newsroom/en/healthcare-and-pharmaceutical/fda-approves-renewal-of-canalevia-ca1-jaguar-healths-drug-for-chemoth-1116220

AVMA News I Computed tomographic features of renal neoplasms in dogs: introduction of the collateral vessel sign in veterinary medicine

Michele Occhiuzzi, DVM , Swan Specchi DVM, PhD, DACVR , Roberto Rabozzi DVM , Simone Teodori DVM , Caterina Puccinelli DVM, PhD , Erica Visconti DVM , Samuele Berti DVM, Laura Brizzi DVM, and Simonetta Citi DVM, PhD

December 5, 2025

Abstract

Objective

To assess the role of CT in detecting canine renal neoplasms and describe their imaging features.

Methods

32 dogs with histologically and cytologically confirmed renal tumors were included. Computed tomography scans were reviewed for qualitative parameters: lesions number, size, margins, enhancement pattern, mineralization, laterality, intrarenal location, hemorrhage, lymphadenopathy, pulmonary metastases and collateral vessels. Quantitative parameters included lesion diameter and pre- and postcontrast attenuation. Data distribution was tested with the Shapiro-Wilk test, and intergroup differences were evaluated using the Fisher exact test.

Results

Diagnoses comprised primary renal tumors—renal cell carcinoma (RCC; 12 of 32), sarcoma (2 of 32), hemangiosarcoma (1 of 32), primary lymphoma (1 of 32), and cystic adenoma (1 of 32)—as well as multicentric lymphoma (ML; 5 of 32) and metastatic lesions (10 of 32). Primary tumors were mainly unilateral masses, whereas ML and metastases appeared as bilateral nodules. Collateral vessels were significantly more frequent in RCC than in ML or metastases and were also associated with mass lesions rather than nodular lesions. Multicentric lymphoma showed more homogeneous postcontrast enhancement than primary tumors.

Conclusions

CT provides key information to differentiate canine renal tumor types. Collateral vessels may indicate RCC and are more prevalent in mass lesions; therefore, they should be considered in surgical planning. Canine lymphoma showed CT features consistent with human reports, although overlap among tumor subtypes reduced specificity.

Clinical Relevance

This study describes novel tomographic features of canine renal neoplasia and comprehensively summarizes their CT characteristics, aiding diagnosis and treatment planning.

Keywords: neoplasia; computed tomography; dog; collateral vessels; kidney

Renal neoplasms in dogs are considered uncommon, accounting for less than 1% of all neoplastic diseases and approximatively 2% of all malignant tumors.1,2 Primary renal neoplasms are extremely rare, reported in only 0.3% of oncologic canine patients.1,2 Among these, epithelial neoplasms, such as renal cell carcinoma (RCC, all acronyms are listed in Supplementary Table S1), transitional cell carcinoma, adenoma, and papilloma, have been described.2 Various types of sarcomas can also affect the kidneys, including hemangiosarcoma (HSA), renal sarcoma, leiomyosarcoma, malignant fibrous histiocytoma, spindle cell sarcoma, fibroleiomyosarcoma, lipoma/liposarcoma, and teratoma.3,4 Other primary renal tumors include nephroblastoma,2 renal interstitial cell tumors,5 renal cystadenocarcinoma—described as a unique hereditary syndrome in German Shepherd Dogs6—and primary renal lymphoma.1,2

Metastatic involvement of the kidneys is more common than primary neoplasms, particularly in cases of disseminated metastatic disease.7 Secondary renal involvement has been reported in epithelial neoplasms arising from the lungs,3 thyroid gland,7 mammary gland,3,7 and ovaries3 as well as in lymphosarcomas,3 mast cell tumors,3 and osteosarcomas.3,7,8

Ultrasonography (US) is widely used for the evaluation of renal lesions in dogs; however, it presents several limitations in discrimination and identification of such lesions. Specifically, US lacks distinctive features that allow reliable differentiation among various massive renal lesions, and a recent retrospective study7 reported that US failed to detect nodules that were isoechoic to the renal cortex and did not protrude from the renal profile.9 Moreover, the quality of US images decreases in large dogs due to the lower-frequency probes required.7

Computed tomography is less influenced by patient size, allows multiplanar image reconstruction, and is less operator dependent.10 Its use has been described in diagnostic protocols for renal neoplasia, offering a comprehensive evaluation that combines staging with high diagnostic accuracy.11 Compared to abdominal US, CT has been shown to be superior in detecting renal nodules.7

Currently, in veterinary medicine, no CT features have been identified that can reliably differentiate between benign and malignant renal neoplasms or among different primary tumor types.12 Therefore, fine-needle aspiration and biopsy remain essential for a definitive diagnosis.9 Fine-needle aspiration is generally considered a safe procedure, whereas renal biopsy is associated with complications, such as arteriovenous fistula formation, hemorrhage, hydronephrosis, infarction, thrombosis, and, in rare cases, death, with complication rates reported between 1% and 18%.13,14 Thus, the ability to differentiate renal lesions through diagnostic imaging could represent a safer and valuable approach.12

In human medicine, CT is considered useful in most urological oncology diagnostic algorithms.15 Several CT features, including lesion size, distribution, enhancement patterns, and the presence of collateral vessels (CVs), assist in lesion characterization.15,16

The aim of this study was to (1) describe the CT findings in dogs affected by renal neoplasia and (2) assess the potential utility of CT in differentiating among the various types of renal neoplastic lesions in dogs.

Methods

Selection and description of subjects

Inclusion criteria were dogs with a cytological or histopathological diagnosis of primary or metastatic renal neoplasia that underwent pre- and postcontrast CT examinations between 2017 and 2024. To minimize potential bias, only patients that were not receiving chemotherapy at the time of the CT examination were included. Data were retrieved from the medical archives of 4 veterinary institutions: Anicura Roma Sud Veterinary Hospital, the “Mario Modenato” Veterinary Teaching Hospital of the University of Pisa, Cetego Veterinary Center in Rome, and Anicura “I Portoni Rossi” Veterinary Hospital in Zola Predosa. Data collection was performed by 3 investigators (OM, VE, and BL) using the keywords “renal neoplasia,” “renal lesion,” and “kidney tumor.” Investigators planned to categorize the patients identified in the initial search according to their final cytological or histopathological diagnosis. Data use was approved by each institution; approval from an IACUC or ethical review board was not required for this retrospective study.

Data recording and analysis

Patient data—For each dog, age, sex, breed, and body weight were recorded. Additionally, the method used to obtain the cytological or histopathological diagnosis of both primary and metastatic lesions was reviewed. For patients undergoing nephrectomy, surgical data were also collected.

CT acquisition protocol—Computed tomography image acquisition was performed using 4 CT scanners: a 16-slice BrightSpeed (GE HealthCare), a 16-slice Revolution Act (GE HealthCare), a 32-slice Somatom Go Up (Siemens Healthineers), and a 128-slice Somatom Perspective (Siemens Healthineers).

All examinations were performed under general anesthesia with patients positioned in sternal recumbency. Acquisition parameters varied slightly depending on the equipment but included helical acquisition mode, 100 to 120 kVp, 150 to 250 mAs, 0.625- to 2.5-mm slice thickness, 0.3- to 2.5-mm reconstruction interval, 512 X 512 matrix, field of view tailored to patient size, and pitch values between 0.5 and 1.3.

Following precontrast image acquisition, iodinated contrast medium (iohexol; Omnipaque; 350 mg/mL) was administered using power injectors at a flow rate of 2 mL/s, with a maximum pressure of 100 lb/square inch and dosage of 600 mg/kg, and then postcontrast imaging was performed.

Images evaluation—Computed tomography images were reviewed using dedicated open-source DICOM software (Horos, version 4.0.0; Horos Project) with both transverse and multiplanar reconstructions. Image datasets were evaluated with soft tissue kernels using window settings of 500:50 (window width to window length).

Two radiologists, each with 7 years of experience (MO and EV), independently reviewed all CT scans. A third radiologist with over 20 years of experience (SC) subsequently verified the collected data. Discrepancies were resolved by consensus. Reviewers were blinded to the final diagnosis, and image sets were analyzed in random order to reduce potential bias.

For each kidney, both qualitative and quantitative CT characteristics were assessed as follows.

Qualitative features included lesion margins (well defined or ill defined) and location (cortical, medullary, or both). Quantitative features included maximum lesion diameter and lesion density. Lesion diameter was measured in transverse, sagittal, and coronal planes, with the largest value recorded. Based on these measurements, lesions were classified by size as nodules (< 3 cm) or masses (≥ 3 cm in maximum diameter). Lesion density was calculated by manually drawing 3 regions of interest (ROIs) within the lesion on both pre- and postcontrast images, avoiding cystic or necrotic areas. The median attenuation value (HU) and SD were recorded. The same procedure was applied to adjacent normal renal parenchyma for comparison. The number of renal lesions was recorded for each patient, and dogs were subsequently classified as having either a single lesion or multifocal lesions (defined as ≥ 2 lesions). The presence of intralesional mineralization and postcontrast enhancement patterns was also recorded. Enhancement was classified as homogeneous or heterogeneous. Enhancement heterogeneity was evaluated as described in the statistical analysis section. Other types of enhancement were evaluated for each case by the operators, and a consensus was subsequently reached after discussion. The same process was applied when assessing adjacent organs, retroperitoneal space, and lungs.

Collateral vessels were defined as vascular structures directly connected to the tumor regardless of diameter.16

As previously stated, patients were divided into groups—primary neoplasia, metastatic neoplasia, multicentric lymphoma (ML), RCC, mass-size lesions, and nodular-size lesions—and statistical analyses were performed.

Statistical analysis

Continuous data were tested for normality using the Shapiro-Wilk test and visual inspection. If distribution of the data was normal, then the mean and SD were calculated. Conversely, if the distribution of data was not normal, median and range were computed.

Categorical variables were reported as frequencies and percentages, and differences between groups were analyzed using the Fisher exact test. Continuous variables were assessed for normal distribution through visual inspection of bar graphs and histograms as well as using the Shapiro-Wilk test. Normally distributed variables are reported as the mean ± SD, whereas non–normally distributed variables are expressed as the median (range).

Enhancement heterogeneity was evaluated as follows. Two investigators (MO and CP) manually delineated a single, maximally sized ROI on postcontrast CT images of renal lesions by use of dedicated open-source DICOM software (Horos, version 4.0.0; Horos Project). Cystic or necrotic areas were carefully excluded. The SD of attenuation values within each ROI were recorded.

Enhancement pattern was subjectively classified by the same investigators as heterogeneous or homogeneous based on direct inspection of the postcontrast CT images. In instances of disagreement, a consensus classification was achieved.

The normality of SD values was assessed with the Shapiro-Wilk test. The Mann-Whitney U test was then applied to compare SD values between lesions with heterogeneous and homogeneous enhancement, testing the hypothesis that heterogeneously enhancing lesions would exhibit higher SD values.

A significance level of 5% was established for all statistical methods. Statistical analyses were performed by RR, MO, and CP using a commercially available statistical program (MedCalc Statistical Software, version 23.2.8; MedCalc Software Ltd).

Results

General

A total of 68 dogs were initially identified through database screening. Thirty-six dogs were excluded due to the absence of either a cytological or histopathological diagnosis or lack of available CT images.

Ultimately, 32 dogs met the inclusion criteria. Of these, 9 were female, and 23 were male. Among the females, 4 were neutered, whereas 14 of 23 males were castrated. The median age of the study population was 9.8 years (SD, 2.8).

The most frequently represented breeds were German Shepherd Dog (4 of 32) and Golden Retriever (3 of 32). Other breeds included Dachshund, Flat-Coated Retriever, Rottweiler, Chihuahua, Dobermann, Rhodesian Ridgeback, Cocker Spaniel, Shih Tzu, Lagotto Romagnolo, Maltese, Maremmano-Abruzzese Sheepdog, Labrador Retriever, Bernese Mountain Dog, Italian Mastiff, Siberian Husky, and Miniature Poodle. Additionally, 9 dogs were mixed breed.

Seventeen of 32 dogs were diagnosed with primary renal neoplasia, 5 with ML, and 10 with metastatic renal lesions. Within the primary renal neoplasia group, 12 had RCC, 2 had sarcomas, 1 had a primary renal HSA, 1 had a primary renal lymphoma, and 1 had an adenoma

In the metastatic group, renal lesions were observed in 3 cases of carcinoma (including 2 mammary gland carcinomas and 1 anal sac gland adenocarcinoma [AGASAC]), 3 cases of metastatic HSA, 1 adrenal pheochromocytoma, 1 axillary liposarcoma, 1 osteosarcoma, and 1 histiocytic sarcoma.

Ultrasound-guided fine-needle aspiration for cytological diagnosis was performed in 18 dogs, whereas 14 dogs underwent nephrectomy followed by histopathological examination of the excised lesions.

Regarding CT examinations, although minor differences in acquisition protocols were present, all scans included both baseline images and postcontrast-phase images.

Qualitative CT features

Out of the 32 dogs included in the study, 23 presented unilateral renal lesions, whereas 9 showed involvement of both kidneys. The left kidney was more frequently affected, with 13 lesions located in the left kidney and 10 in the right. All primary renal neoplasms were unilateral, whereas 4 of 5 lymphomas and 5 of 10 metastatic lesions involved both kidneys.

Seventeen of 32 dogs showed large masses, and 15 presented nodular lesions. Within the primary neoplasia group, most patients (15 of 17) had mass lesions, whereas dogs with metastatic renal neoplasia (P = .003) and lymphoma (P = .003) more commonly presented with nodular lesions (9 of 10 and 4 of 5, respectively; This observation was statistically significant.

Lesions were well marginated in most cases (28 of 32). Renal masses were often located near 1 kidney pole, compressing and distorting the adjacent normal renal parenchyma, affecting both cortex and medulla. In larger lesions, the affected kidney was almost entirely replaced by neoplastic tissue, making normal renal structures difficult to identify.

Nine of 32 lesions were located within the renal cortex; all were nodular lesions. Four of these were located at the corticomedullary junction. The renal capsule was deformed in all mass lesions and in the majority of nodular lesions (9 of 15).

Enhancement heterogeneity was significantly associated with higher SD values (P < .001). The median SD for heterogeneously enhancing lesions was 17.73 HU (range, 7.3 to 31.37 HU), whereas the median SD for homogeneously enhancing lesions was 10.57 HU (range, 5.97 to 15.07 HU). The visual assessments performed by the 2 operators were in complete agreement.

In addition to homogenous and heterogenous enhancement, different types of postcontrast enhancement were identified: ring enhancement and spotty postcontrast linear or amorphous strong hyperdensity (SPLASH sign).17

Renal cell carcinoma showed significantly more frequent heterogeneous postcontrast enhancement compared to ML (P = .001) and metastatic lesions (P = .03). The same observation has been noted when comparing RCC and metastatic lesions in terms of intralesional mineralization. However, no significant difference in intralesional mineralization was found when comparing RCC with other primary renal neoplasms or ML.

Moreover, 90% of RCC cases showed the presence of CVs, often consisting of multiple venous and arterial vessels surrounding the renal mass, with variable origin and size. Collateral vessels were significantly more frequent in RCC compared to metastatic neoplasia (P = .001) and ML (P = .001). Collateral vessels were also observed in 1 case of primary renal HSA, 1 case of ML, and 1 case of metastatic pheochromocytoma. Unfortunately, the Fisher exact test showed no statistically significant difference between RCC and other mass lesions regarding the presence of CV. Moreover, the occurrence of CV was significantly higher in mass-size lesions compared to nodular-size lesions (P < .001). Cases diagnosed as renal sarcoma and primary renal HSA showed mass lesions similar to RCC, without evidence of hemorrhage, pulmonary metastases, or renal lymphadenopathy. Primary renal lymphoma presented as a single, unilateral, well-marginated mass with homogeneous postcontrast enhancement. In the case of cystic adenoma, a single cyst-like mass was observed in the left kidney, with a thin, enhancing wall. The inner portion of the lesion showed a hyperdense, heterogeneous, nonenhancing structure, consistent with a sentinel clot sign, later confirmed as intralesional hemorrhage. Moderate retroperitoneal effusion was also present. No CT features were useful in distinguishing among different primary renal neoplasms, as the Fisher exact test revealed no statistically significant differences between these groups.

The ML group showed a significantly higher frequency of nodular (P = .003), multifocal (P < .001), and bilateral (P < .001) lesions, with homogeneous enhancement patterns (P < .001), compared to the primary renal neoplasia group. No statistically significant CT features were identified for differentiating ML from metastatic renal neoplasia.

Metastatic renal lesions were more frequently nodular (P < .001) and bilateral (P = .003) compared to primary neoplasia. Specifically, a single renal nodule was observed in 1 case of AGASAC. In cases diagnosed with metastatic HSA, all dogs exhibited the SPLASH sign, associated with a sentinel clot sign and irregular lesion margins, consistent with hemorrhagic rupture. In the metastatic pheochromocytoma case, a strongly hyperenhancing renal nodule was observed, with extensive invasion of the caudal vena cava and left renal vein originating from an adrenal mass.

In the case of metastatic liposarcoma, a heterogeneous axillary mass with negative attenuation values was detected, along with multifocal renal nodules in both kidneys, lungs, muscles, and axillary lymph nodes. These renal lesions also exhibited negative attenuation values on precontrast images. In the metastatic osteosarcoma case, bilateral, heterogeneously enhancing renal masses were identified. Multifocal renal nodules were observed in a Bernese Mountain Dog diagnosed with histiocytic sarcoma.

Analyses of adjacent organs, retroperitoneal space, and lungs revealed renal lymphadenopathy (lymph nodes > 5 mm in diameter)18 in 11 of 32 cases, retroperitoneal effusion in 7 of 32 cases, sentinel clot sign (hyperattenuating hematoma adjacent to a bleeding organ)19 in 7 of 32 cases, and suspected pulmonary metastasis (multifocal nodular lung lesions) in 6 of 32 cases.

Quantitative CT features

Continuous variables were lesion maximum diameter, CT attenuation, and patient age. The mean diameter was 8.1 cm (SD, 2.7) in the primary neoplasia group, 1.7 cm (SD, 0.7) in the metastatic renal lesions group, and 2.2 cm (SD, 1.6) in the ML group. Regarding CT density (HU), the median values in basal scan were 37.8 (range, 16.0 to 60.4) in primary neoplasia, 57.4 (range, 28.8 to 91.0) in ML, and 36.1 (range, −1.3 to 51.4) in metastatic neoplasia. The values in the nephrographic phase were 74.7 (range, 35.7 to 85.0) in primary neoplasia, 103.6 (range, 60.1 to 108.7) in ML, and 75.73 (range, 22.8 to 182.9) in metastatic neoplasia.

Discussion

Renal cell carcinoma was the most frequent primary renal tumor in our study, consistent with the incidence rates reported in the veterinary literature.20 In dogs diagnosed with RCC, the lesions were typically large, encapsulated masses, frequently located near one of the renal poles, in agreement with these well-documented characteristics of RCC.3,4,20,21 Histologically, RCC can present with different subtypes, including clear cell (accounting for approx 9% of cases and associated with a poorer prognosis), chromophobe, papillary, and multilocular cystic variants.21 These subtypes may coexist within the same lesion.3 In human medicine, postcontrast CT enhancement patterns have been correlated with different RCC subtypes.22 Unfortunately, in our study, information regarding RCC subtypes was unavailable.

Our results align with those of previous studies, indicating that RCC exhibits variable metastatic potential, ranging from moderate (16% to 34%) to high (70% to 75%) depending on the timing of diagnosis. Reported metastatic sites include the contralateral kidney (with approx 5% of cases presenting bilateral lesions), abdominal organs, omentum/peritoneum, lungs, bones, and renal lymph nodes.2,21 Pulmonary metastases have been documented in 18% to 48% of affected dogs, with an overall metastatic rate at the time of death reaching 69%.4,12,21

Regarding CT images, none of the evaluated findings in this study proved useful in distinguishing RCC from other primary renal tumors. Previous studies have attempted to establish a correlation between CT features and histopathological diagnosis of primary renal neoplasms. However, no statistically significant associations have been identified between imaging findings and histological diagnoses for the 3 most common primary renal tumors (RCC, HSA, and lymphoma).12

Heterogeneous enhancement in RCC, due to intralesional hemorrhage and necrosis, has been consistently reported, and our observations confirm these findings.12

Intralesional mineralization has been described in canine soft tissue tumors, such as extraskeletal osteosarcoma,23 dedifferentiated chondrosarcoma,24 liposarcoma,25 and isolated case reports.26,27 To the best of our knowledge, mineralization within RCC has not been previously documented in canine CT studies and overall remains an uncommon finding.12,23 Consequently, this observation may represent a novel discriminating factor in the diagnosis of RCC.

In human medicine, the presence of CV is considered a useful CT sign to differentiate RCC from other renal masses, such as fat-poor angiomyolipomas. Collateral vessels are associated with increased tumor angiogenesis and are more frequently observed in aggressive RCC subtypes, such as clear cell carcinoma. Mechanisms underlying neoangiogenesis in clear cell RCC have been well documented. Neoplastic cells frequently harbor mutations in the von Hippel–Lindau tumor suppressor gene, leading to dysregulation of hypoxia-inducible factors 1α and 2α, which, in turn, promote neoangiogenesis.28 Collateral vessels have been reported to provide a sensitivity, specificity, positive predictive value, and negative predictive value of 48.5%, 45.5%, 100%, and 95%, respectively, for RCC diagnosis.16 Additionally, in humans, RCCs are often detected as small renal masses with a diameter of less than 4 cm.16 In contrast, RCCs in dogs tend to be larger at the time of diagnosis, likely due to their subclinical progression, allowing for significant tumor growth before detection.4 Consequently, the increased angiogenic stimulus associated with larger neoplastic lesions may reduce the diagnostic reliability of CV as a specific CT feature for RCC.29

Therefore, CV may be related to both tumor size and histopathological diagnosis in light of the neoangiogenic mechanisms in RCC that are well characterized in human medicine. Our observations of reduced pulmonary metastasis and renal lymphadenopathy in dogs with primary renal sarcoma compared to those with RCC suggest that sarcomas may exhibit lower malignancy. However, due to the small number of sarcoma cases, statistical comparison with the RCC group was not feasible.

Primary renal HSA is considered a rare neoplasm in dogs compared to visceral or retroperitoneal forms. According to the available literature, dogs with renal HSA may have a more favorable prognosis than those with other forms, although prognosis worsens in the presence of retroperitoneal hemorrhage at diagnosis.30 Hemorrhage is infrequently reported, likely due to the anatomical location and specific histological characteristics of renal HSA.30 Our findings are consistent with these observations. On CT, renal HSA may demonstrate contrast enhancement in the corticomedullary phase, with gradual contrast expansion around vessels. This pattern likely reflects the histologic architecture of HSA, characterized by multiple cavernous, anastomosing vascular spaces.12 Additionally, renal HSA lesions may appear hypoattenuating on CT, likely due to inadequate vascular supply and extensive cystic areas containing hemorrhage and necrosis.31 Enhancement patterns are variable, ranging from marked vascular enhancement in early phases to heterogeneous or poor enhancement in delayed phases.31,32 In our study, the absence of large cavitary areas and marked perivascular enhancement differed from previous reports, although statistical evaluation was not possible due to the limited number of cases.

Renal adenomas are rarely described in dogs and may be difficult to distinguish from carcinoma based on imaging alone. Macroscopically, they usually appear as single, expansively growing nodules.3,33 Cystic adenomas are even more infrequently reported, with only isolated case descriptions available.34 In our study, CT was useful for presumptive diagnosis and surgical planning. To the best of our knowledge, this represents the first CT description of a cystic renal adenoma with intralesional hemorrhage in dogs.

In human medicine, renal lymphoma may present as multiple lesions, solitary masses, contiguous perirenal extension, or diffuse perirenal involvement.35 Mass pattern could present as homogeneously enhancing renal masses, a characteristic attributed to the absence of intralesional necrosis.35 Most commonly, patients present with multiple lesions, similar to the renal nodules observed in dogs with ML in our study. To our knowledge, this is the first description of CT findings of renal involvement in canine ML. However, CT was not helpful in distinguishing renal lesions associated with ML from those due to metastatic disease. Primary renal lymphoma remains poorly described in the veterinary literature.12 Bilateral, multiple renal masses have been reported as typical CT findings in dogs.12 In our study, primary renal lymphoma lesions resembled those described in mass human pattern, differing from previous canine reports. However, the small sample size precluded statistical analysis.

In a human autopsy study,36 renal metastases have been detected in 7% to 12% of cases, whereas diagnostic imaging studies report a lower incidence of approximately 0.9%.37–40 Metastases most commonly originate from primary tumors of the lung, gastrointestinal tract, breast, soft tissue, and thyroid.39 Various imaging modalities, including CT, MRI, and contrast-enhanced ultrasound, have been used to detect these lesions, with comparable diagnostic performance.40

Computed tomography findings of renal metastases are often nonspecific.37 They typically appear as bilateral, multifocal nodules with reduced contrast enhancement relative to normal renal parenchyma and preservation of renal contours.41 While intralesional mineralization has been described in metastatic mucoid carcinoma, papillary carcinoma, osteosarcoma, and chondrosarcoma,42 such findings are rare,37 and definitive diagnosis often requires biopsy.43

In veterinary medicine, renal metastases are rarely reported; only isolated cases have been described, including metastases from nasal chondrosarcoma and from extramedullary plasmacytoma of the oral cavity.44,45 In small animals, renal metastases typically present as bilateral, nodular lesions.7 Our observations confirm these findings. No CT findings were able to differentiate between different metastatic lesions. Notably, unlike in human patients, renal metastatic lesions in our canine cases frequently distorted renal contours and did not exhibit intralesional mineralization, even in cases of osteosarcoma.

Carcinoma was the most common primary tumor associated with renal metastasis in our cohort. In 1 dog with AGASAC, a breed predisposition (Cocker Spaniel) was observed, consistent with the known biological behavior of this tumor type.46

Our findings regarding extrapulmonary metastasis of HSA align with previous reports describing heterogeneous enhancement with central or peripheral linear or amorphous areas of contrast uptake, known as the SPLASH sign. This CT feature corresponds to a distinct pattern of contrast enhancement that may assist in the diagnostic assessment of HSA.17 It was described in a recent retrospective observational study,17 in which the authors identified this feature in 75% of renal HSA metastases. Its presence has been associated with neoangiogenesis, leading to the formation of new vascular channels, or with fluid-filled hemorrhagic intralesional areas.17

In contrast to metastatic HSA, no evidence of hemorrhage was observed in primary renal HSA in our study despite histological difficulties in differentiating primary from metastatic lesions.30 Primary HSA typically appeared as large, space-occupying masses with significant necrosis and a high risk of rupture, suggesting potential histopathological differences between primary and metastatic renal HSA. However, the limited number of HSA cases precluded statistical confirmation, highlighting the need for further research.

Computed tomography characteristics of adrenal pheochromocytomas have been described, and our findings are consistent with those reports.47 Histologically, pheochromocytomas may exhibit telangiectatic areas with distended vascular spaces and hemorrhage, which likely explain the contrast enhancement pattern observed in our case.48 Statistical evaluation was not possible due to the single case.

The CT appearance of liposarcomas in dogs has been described, although reports of metastatic liposarcomas are rare, with only 1 documented case of hepatic metastasis from an axillary liposarcoma.49,50 To the best of our knowledge, this is the first report of renal metastasis from a liposarcoma in a dog.

Our findings related to metastatic osteosarcoma and histiocytic sarcoma were consistent with previously reported data in veterinary literature.8,51

The limitations of our study include the following:

(1)Due to the retrospective design, a standardized CT acquisition protocol could not be applied; therefore, the analysis was based on the available postcontrast images.

(2)There was an absence of histopathological confirmation for all cases as well as a lack of immunohistochemical characterization; this fact prevented us from linking CV to specific subtypes of RCC that rely on hypoxia-driven mechanisms to promote neoangiogenesis.

(3)Although the sample included 32 dogs, the number of cases in each subgroup was small, and no control group was available for comparison.

(4)Although the operators were blinded to the final diagnosis, they were aware that all renal lesions included in the study were neoplastic due to the predetermined inclusion criteria, which may have introduced a potential source of bias.

(5)As previously mentioned, a considerable number of cases from the initial database search did not meet the inclusion criteria; this limitation is likely related to the referral-based structure of the diagnostic imaging sections of the participating veterinary institutions.

Our study demonstrated that, in canine patients with renal neoplasia, certain CT features showed statistically significant differences between groups. Multicentric lymphoma and metastatic neoplasia more frequently presented as bilateral, nodular renal lesions, whereas primary tumors were more commonly characterized as unilateral masses. Among primary tumors, RCC was significantly more likely to exhibit CVs compared to lymphoma and metastatic neoplasia. Collateral vessels are a novel tomographic sign that has not previously been described in dogs. Although this finding reached statistical significance when comparing RCC with other neoplastic entities, a significant difference was likewise observed between mass-size and nodular-size lesions in terms of CV occurrence.

Further studies with larger sample sizes are warranted to determine whether the presence of CV is truly associated with the type of neoplasia or is simply a consequence of lesion size. Nonetheless, considering that nephrectomy remains an effective treatment option in metastatic-free patients,2,4,30 the detection of CV on CT could be a valuable tool for presurgical planning. Compared to metastatic neoplasia, RCC more frequently exhibited intralesional mineralization, a feature that should therefore be considered in the differential diagnosis of mineralized renal masses.

In patients with ML, postcontrast enhancement was more commonly homogenous compared to primary renal neoplasms. However, no CT features demonstrated statistical significance in differentiating ML from metastatic renal lesions. The description and characterization of secondary renal tumors provided by this study may serve as a foundation for future research aimed at improving diagnostic accuracy.

In conclusion, while CT can assist in guiding the differential diagnosis of certain renal neoplastic lesions in dogs, definitive diagnosis still requires fine-needle aspiration and histopathological evaluation. Our research introduces novel tomographic signs, such as CVs, and provides a detailed description of CT features in canine renal neoplasia.

Supplementary Materials

Supplementary materials are posted online at the journal website: avmajournals.avma.org.

Acknowledgments

The authors thank Fidelia Fasano, DVM, for her help with data acquisition at Anicura Roma Sud Veterinary Hospital.

Disclosures

The authors have nothing to disclose. No AI-assisted technologies were used in the composition of this manuscript.

https://avmajournals.avma.org/view/journals/ajvr/aop/ajvr.25.09.0342/ajvr.25.09.0342.xml

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DVM 360 | Understanding oncology diagnostics and therapeutics

Multiple approaches to cancer treatment can be initiated by primary care veterinarians.

December 3, 2025

Author(s)Craig A. Clifford DVM, MS, DACVIM (Oncology), Christine Mullin VMD, DACVIM (Oncology)

What can primary care veterinarians do to provide care to patients with cancer? These approaches can help guide treatment.

Staging is a critical step in cancer patient management, but it does not always require referral to a specialist to be performed effectively. Most staging procedures—such as complete blood count, serum chemistry panel, cytologic evaluation of regional lymph nodes, and 3-view thoracic radiographs—are standard diagnostic tests readily available in general practice.

These tools provide essential information about the extent of disease, metastatic potential, and overall patient health, guiding both treatment decisions and client expectations. For example, aspirating a regional lymph node in a dog with a mast cell tumor or obtaining thoracic radiographs in a soft tissue sarcoma or osteosarcoma case are impactful yet straightforward steps that can be performed in-house. When these results accompany a referral, they not only streamline case management but also reduce client costs and improve continuity of care. By recognizing that cancer staging is based upon the same diagnostic principles used in primary care, veterinarians can confidently contribute to accurate diagnosis, timely treatment planning, and collaborative oncology care.

Key tests for primary care 

• Lymphoma: Complete blood count (CBC), serum chemistry, consider 3-view thoracic radiographs with radiologist review

• Mast cell tumor: CBC, serum chemistry, consider regional lymph node cytology

• Soft tissue sarcoma: CBC, serum chemistry, 3-view thoracic radiographs with radiologist review

• Osteosarcoma: CBC, serum chemistry, radiographs of affected limb, 3-view thoracic radiographs with radiologist review

• Melanoma: Mass measurement and photo, CBC, serum chemistry, 3-view thoracic radiographs with radiologist review, regional lymph node cytology

Clinical takeaways

Performing baseline staging in-house supports faster case turnover, more informed prognostication, and smoother communication with oncology referral centers. Most initial cancer staging can be efficiently and accurately performed by primary care veterinarians, expediting or even in some cases replacing oncology referral and reducing client cost.

Diagnosing lymphoma with a blood test

The IDEXX Cancer Dx is a new blood-based screening/diagnostic panel aimed at detecting canine lymphoma from serum or whole blood. It reports the presence or absence of lymphoma-associated circulating biomarkers and, when positive, can provide a B- vs T-cell phenotype classification in some cases.1

Key performance numbers2:

• Sensitivity: ~79% for dogs with lymphoma in IDEXX’s internal validation.
• Specificity: ~99% versus healthy controls and dogs with inflammatory disease/other cancers in the same internal dataset.

Practical details:

• Sample: single blood draw (serum or whole blood). Interference from mild–moderate hemolysis, lipemia, or icterus is reportedly minimal.
• Intended use cases highlighted by IDEXX:
• Dogs suspected of having lymphoma
• Cancer screening for apparently healthy “at-risk” dogs (IDEXX suggests integration within wellness panels for older dogs).
• Cost/rollout: IDEXX promotes the test as low-cost (advertised as starting around US$15 as an add-on) and has been available in the US and Canada as of March 2025.1

How to use it in primary care:

• If lymphoma is suspected clinically (lymphadenopathy, constitutional signs, cytology suspicious): Cancer Dx can be run on the blood sample as a noninvasive adjunct, but positive results still require confirmation with cytology/biopsy/flow/PCR for antigen receptor rearrangement (PARR) as clinically indicated. A negative result does not rule out lymphoma because sensitivity is <100%.
• If used for screening (as an add-on in older / at-risk dogs): discuss with owners that the test increases the chance of detecting lymphoma earlier, but is not a guarantee—explain the possibility of false negatives and what you’d do if the test is positive (confirmatory diagnostics, staging conversation).

Clinical takeaways
The IDEXX Cancer Dx is a practical, low-cost blood test that helps detect canine lymphoma earlier and in some cases supplies phenotyping information useful for initial case planning. It’s a reasonable adjunct for dogs with clinical suspicion and an attractive screening add-on for older/at-risk dogs — but it is not diagnostic by itself. Use positive results to prompt confirmatory diagnostics such as cytology/biopsy/flow cytometry/PARR, and use clinical judgment for negative results because sensitivity is not 100%. Consider the current evidence base (IDEXX internal validation data only) and watch for independent peer-reviewed studies as they emerge.

Immunophenotyping Canine Lymphoma

Immunophenotyping (determining B-cell vs. T-cell origin) is now considered a standard part of lymphoma diagnosis because it directly influences prognosis and treatment expectations. Multiple studies confirm that dogs with T-cell lymphoma have shorter survival times and lower response rates to standard CHOP chemotherapy compared to dogs with B-cell lymphoma.

• In one study, T-cell lymphoma had only a ~50% response rate to single-agent doxorubicin, versus nearly 100% for B-cell lymphoma.3
• T-cell protocols incorporating alkylating agents such as lomustine (CCNU) have shown partial responses in ~60% of cases and complete responses in 17%.4
• Modified multiagent protocols (eg, L-MOPP, CCNU-based CHOP variants) may offer benefit, but toxicity and practicality limit their use in general practice.5
• A prospective study comparing CHOP +/- the investigational agent AT-005 in T-cell lymphoma demonstrated similar response rates (~65% CR) and median progression-free survival (64–103 days), confirming that outcomes remain inferior to B-cell lymphoma.6

Methods for immunophenotyping

Flow cytometry (preferred):

• Most informative test of all those available. Confirms B-cell vs. T-cell, but also provides additional prognostic markers that can indicate grade and expected behavior
• Can be performed on tissue aspirate (ie, lymph node, organ) or fluid (ie, blood, effusions, CSF)
• Requires live cells in media and overnight shipping
• Available at multiple academic and reference labs

PARR:

• Can be performed on both cytology and biopsy samples
• Only confirms B-cell vs. T-cell status, does not provide grade
• Available at most academic and reference labs

Immunocytochemistry (ICC):

• Can be performed on cytology slides
• Somewhat subjective
• Available at some academic and reference labs

Clinical takeaways
Primary care veterinarians can play a crucial role by determining lymphoma immunophenotype before referral and treatment initiation, allowing the care team and pet owners to have a more informed and directed conversation about treatment options and expected prognosis.

B-cell: CHOP-based therapy remains standard, potentially good long-term prognosis.

T-cell: Expect shorter remission; consider referral or alternate protocols.

Cytologic Grading of Mast Cell Tumors (MCTs)

Traditional histologic grading remains the gold standard, but cytologic grading is validated as a noninvasive, predictive tool when tissue biopsy isn’t feasible or clinically indicated. Studies have shown that specific cytologic features—including mitotic figures, multinucleation, nuclear atypia, and karyomegaly—strongly correlate with histologic grade and outcome.

Cytologic grading predicted histologic grade in 94% of cases.7

Cytologic grading carries an 88% sensitivity and 94% specificity relative to histopathology.8

Compared to low-grade tumors , cytologically high-grade MCTs are 25–39 times more likely to result in death within 2 years.7

Clinical takeaways

For general practitioners, cytologic grading provides a rapid, low-cost prognostic tool that can guide surgical planning and inform prognosis. Communicate with reference laboratory to ensure that cytologic grading can be provided for MCT submissions. 

Noninvasive diagnosis of Transitional Cell Carcinoma (TCC)

The BRAF mutation test (CADET BRAF Mutation Detection Assay) represents one of the most impactful molecular diagnostics in veterinary oncology. Independent studieshave identified a single-point mutation (V595E) in the canine BRAF gene that is present in ~85% of TCC/urothelial carcinoma (UC) cases, but absent in benign or inflammatory bladder conditions. 9,10

This assay detects the mutant DNA in urine sediment, allowing:

• Noninvasive diagnosis without aspirate, cystoscopy, or surgical biopsy

• Early detection—often months before clinical signs

• Monitoring for response to treatment and early detection of recurrence

A secondary test now detects an additional ~10% of previously negative cases. The test is offered through Antech Diagnostics (BRAF Plus; Sentinel Biomedical platform).

Clinical takeaways

• Consider this test for any dog with persistent hematuria, pollakiuria, or suspicion of a urinary tumor.

• Submit a free-catch or catheterized urine sample for CADET BRAF testing before pursuing more invasive diagnostics such as prostatic wash for cytology, cystoscopy, or biopsy.

• This test eliminates the need for needle aspiration of urinary tumors, a known risk for tumor seeding.

• This test is 100% specific, so can be performed in dogs with known or suspected urinary tract infection (UTI) without concern for a false positive result.

Oncologic therapies available in primary care practice

Use of verdinexor (Laverdia-CA1; Dechra)

Verdinexor is an oral anticancer medication conditionally approved by the FDA for the treatment of lymphoma in dogs. It belongs to a novel class of compounds known as Selective Inhibitors of Nuclear Export (SINE), which work by trapping tumor suppressor proteins inside the nucleus, thereby restoring normal control of cell growth and promoting cancer cell death.

For the primary care veterinarian, verdinexor offers an important at-home treatment option for canine lymphoma—particularly when referral for multiagent chemotherapy is not possible, or when a client prefers palliative care that still provides measurable clinical benefit. 

Efficacy and clinical use

In a multicenter phase II study of dogs with both B-cell and T-cell lymphoma, verdinexor achieved a clinical benefit rate of 55% (stable disease or better), with a median duration of benefit of 71 days (range 21–273 days). Notably, T-cell lymphoma cases, which are often less responsive to traditional chemotherapy, still showed a 71% clinical benefit rate.11 Commonly reported adverse effects are mild and include transient loss of appetite, lethargy, or gastrointestinal upset, which can often be managed symptomatically.

This makes verdinexor a reasonable monotherapy option for:

• Dogs that cannot undergo intravenous chemotherapy.

• Patients that have relapsed after CHOP-based treatment.

• Owners seeking palliative oral therapy that maintains quality of life.

How SINE drugs work with other chemotherapy agents

In addition to its single-agent activity, the SINE drug class has shown synergistic and sensitizing effects when combined with other chemotherapeutics such as doxorubicin and platinum-based agents. These effects may help:

• Sensitize lymphoma cells to respond better to chemotherapy.

• Reverse or delay drug resistance that develops after cytotoxic treatment.

Verdinexor vs prednisone: Impact on drug resistance

Historically, prednisone has been used for palliative treatment of lymphoma, but glucocorticoids can induce multi-drug resistance (MDR) by increasing P-glycoprotein expression in lymphoma cells—reducing the efficacy of subsequent chemotherapy and worsening prognosis.12

In contrast, verdinexor is not a substrate for P-glycoprotein, meaning it should not promote MDR or interfere with future chemotherapy response. In clinical studies, dogs receiving prednisone alone survived an average of 4–7 weeks, whereas verdinexor therapy offers a longer median benefit with potentially improved quality of life.11

Potential novel uses

Cutaneous (epitheliotropic) lymphoma is a challenging disease to treat, with lomustine & prednisone considered the current standard of care. New data suggests that verdinexor has efficacy vs. this form and may serve as a novel second line agent.13,14

Clinical takeaways

• Verdinexor oral tablet can be prescribed and monitored in a general practice setting.

• It provides a targeted, noncytotoxic option for dogs with newly diagnosed or relapsed lymphoma.

• It can be considered a bridge between comfort care and referral for chemotherapy.

• Technicians play a key role in client education—reviewing safe handling, side-effect monitoring, and adherence.

Tigilanol tiglate (Stelfonta; Virbac)—A localized therapy for canine mast cell tumors (MCT)

Tigilanol tiglate is a novel anticancer protein kinase C activator that is FDA-approved for the treatment of certain canine MCTs. Tigilanol tiglate was originally isolated from the seed of the Australian tree Fontainea picrosperma and is now formulated for intratumoral injection.15 Tigilanol tiglate is approved for dogs with all grades of non-metastatic MCTs, including:

• Any cutaneous MCT

• Subcutaneous MCTs located at or distal to the elbow or the hock

• Note: Tumors must be £10 cm3 in volume and accessible for intratumoral injection

How it Works

• Tigilanol tiglate (1 mg/ml) is injected via a single puncture site into the tumor, then the dose is distributed by fanning the needle throughout the tumor mass.

• Dose to be injected is calculated based upon tumor volume (Modified Ellipsoid Method, in cm3): https://stelfonta.com/how-to-calculate-correct-stelfonta-dose/

• Once injected, tigilanol tiglate induces a rapid and localized inflammatory response and destruction of local blood supply to the tumor primarily via ischemic necrosis.

• Healing of the affected area occurs with minimal scar formation.

• Most wounds heal within 4-6 weeks; full healing was observed within 3 months in 98.2% of cases16

Efficacy

In a prospective study, a single tigilanol tiglate treatment resulted in 75% complete response (CR) by 28 days, with that CR maintained in 94% of dogs by 84 days and 89% of dogs by 12 months.17 Dogs not achieving a complete response with the first treatment can receive a second treatment, which results in an improved overall CR rate of 88%. Another more recent study (showed similar results—75% CR rate after a single treatment, with that CR lasting at least 1 year in 64% of dogs.18

Adverse Effects

Adverse effects of tigilanol tiglate are typically low grade, transient, and directly associated with the mode of action. These include:

• Wound formation (possibly extensive) following tumor necrosis and slough

• Localized pain, swelling, erythema, and bruising at the tumor site

• Lameness in a treated limb

• Regional lymph node enlargement

Suggested visit schedule:

• Day 0 – injection

• Day 2 or 3 – check site to confirm necrosis occurring

• Day 7 – assess wound

• Day 28 – reassess wound

• Further visits will be dependent upon patient response and wound healing

Tricks of the trade

• Perform cytologic grading since histopathology will not be obtained

• If cytologically high grade, expect lower response rate

• Systemic therapy is warranted for high grade MCTs

• Perform regional lymph node cytology to confirm nonmetastatic prior to administering tigilanol tiglate.

• Bandaging and Elizabethan collars are not recommended, as the dog’s licking helps remove necrotic tumor tissue from the site.

• The treatment site is considered a “clean” wound, so antibiotics are likewise not commonly needed.

• Consider previsit anti-anxiety and analgesic drugs and/or injectable sedation for treatment of very active or agitated patients.

• Wear personal protective equipment including gloves, protective eye wear, and a lab coat or gown when handling and administering this product.

• Caution is required during treatment to avoid accidental self-injection, which may cause severe wound formation.

Clinical takeaways

Tigilanol tiglate is not for every case, but can be a viable nonsurgical option for the following cases:

• Dogs with multiple low grade MCT

• Dog whose owner whoelectsagainst surgery

• Dogs with a tumor in a challenging location to obtain a complete surgical removal

References

1. McCafferty C. Affordable early detection test for canine lymphoma to hit the market. dvm360. January 27, 2025. Accessed December 3, 2025. https://www.dvm360.com/view/affordable-early-detection-test-for-canine-lymphoma-to-hit-the-market
2. Connell D, Drake C, Michael H, Nascimento, Stuart S, Lyons H. Performance of IDEXX Cancer Dx testing for detection of lymphoma and corresponding phenotype in dogs. IDEXX. 2025. Accessed December 3, 2025. www.idexx.com/files/cancer-dx-white-paper-en-na.pdf
3. Beaver LM, Strottner G, Klein MK. Response rate after administration of a single dose of doxorubicin in dogs with B-cell or T-cell lymphoma: 41 cases (2006-2008). J Am Vet Med Assoc. 2010;237(9):1052–1055. doi:10.2460/javma.237.9.1052
4. Brodsky EM, Maudlin GN, Lachowicz JL, Post GS. Asparaginase and MOPP treatment of dogs with lymphoma. J Vet Intern Med. 2009;23(3):578–584. doi:10.1111/j.1939-1676.2009.0289.x
5. Rebhun RB, Kent MS, Borrofka SAEB, Frazier S, Skorupski K, Rodriguez CO. CHOP chemotherapy for the treatment of canine multicentric T-cell lymphoma. Vet Comp Oncol. 2011;9(1):38–44. doi: 10.1111/j.1476-5829.2010.00230.x
6. Musser ML, Clifford CA, Bergman PJ, et al. Randomised trial evaluating chemotherapy alone or chemotherapy and a novel monoclonal antibody for canine T-cell lymphoma: a multicentre US study. Vet Rec Open. 2022;9(1):e49. doi:10.1002/vro2.49
7. Camus MS, Priest HL, Koehler JW, et al. Cytologic criteria for mast cell tumor grading in dogs with evaluation of clinical outcome. Vet Pathol. 2016;53(6):1117–1123. doi:10.1177/0300985816638721
8. Scarpa F, Sabattini S, Bettini G. Cytological grading of canine cutaneous mast cell tumours. Vet Comp Oncol. 2016;14(3):245–251. doi:10.1111/vco.12090.
9. Hanazono K, Fukumoto K, Endo Y, et al. Ultrasonographic findings related to prognosis in canine transitional cell carcinoma. Veterinary Radiology and Ultrasound. 2013;55(1):79–84. doi:10.1111/vru.12085
10. Mochizuki H, Kennedy K, Shapiro SG, Breen M. BRAF mutations in canine cancers. PLoS One. 2015;10(6):e0129534.doi: 10.1371/journal.pone.0129534.
11. Sadowski AR, Gardner HL, Borgatti, A, et al. Phase II study of the oral selective inhibitor of nuclear export (SINE) KPT-335 (verdinexor) in dogs with lymphoma. BMC Vet Res. 2018;14(1):250. doi:10.1186/s12917-018-1587-9
12. Bergman PJ, Ogilvie GK, Powers BE. Monoclonal Antibody C219 Immunohistochemistry Against P-Glycoprotein: Sequential Analysis and Predictive Ability in Dogs With Lymphoma. J Vet Intern Med. 1996;10(6):354-359. doi:10.1111/j.1939-1676.1996.tb02080.x
13. Vlodaver EM, Keating MK, Bidot WA, Bruyette DS, Rosenkrantz WS, et al. Open-label pilot study: Efficacy of verdinexor for naïve canine epitheliotropic cutaneous T-cell lymphoma. Vet Dermatol. 2024;35(1):536-546. doi:10.1111/vde.13280
14. Grady JL, Gencher J, Adrianowycz S, Martinez-Romero G. Clinical remission of cutaneous lymphoma in a dog treated with verdinexor. J Am Anim Hosp Assoc. 2024;60(5):223-226. doi:10.5326/JAAHA-MS-7443
15. Miller J, et al. Dose characterization of the investigational anticancer drug tigilanol tiglate (EBC-46) in the local treatment of canine mast cell tumors. Front Vet Sci. 2019;6:106. doi:10.3389/fvets.2019.00106
16. Reddell P, De Ridder TR, Morton JM, et al. Wound formation, wound size, and progression of wound healing after intratumoral treatment of mast cell tumors in dogs with tigilanol tiglate. J Vet Intern Med. 2021;35(1):430-441. doi:10.1111/jvim.16009
17. Jones PD, Campbell JE, Brown G, Johannes CM, Reddell P. Recurrence-free interval 12 months after local treatment of mast cell tumors in dogs using intratumoral injection of tigilanol tiglate. J Vet Intern Med. 2021;35(1):451–455. doi:10.1111/jvim.16018
18. Musser ML,Jones PD,Goodson TL,Roof E,Johannes CM.Response to tigilanol tiglate in dogs with mast cell tumors. J Vet Intern Med. 2024; 38(6):3162-3169. doi:10.1111/jvim.17211

https://www.dvm360.com/view/understanding-oncology-diagnostics-and-therapeutics

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American Humane Society I Cold-Weather Pet Tips

People who live in areas experiencing cold weather and winter storms need to take extra precautions to keep their animals safe. Pets left to fend for themselves in cold weather are susceptible to injury and death. Here are some simple tips from American Humane:

Be Prepared

• Plan ahead and pay attention to cold-weather warnings.
• Unless significant power outages are experienced, most cold-weather episodes and winter storms are “shelter in place” events, so pet care needs should be planned for in the home. Keep your pet preparedness kit well-stocked and ready — in a winter storm, you may not be able to leave your home for several days.
• Leave your pets’ coats a little longer in the winter to provide more warmth. That summer “short cut” from your groomer should be avoided during cold weather. If you have short-haired breeds, consider getting them a coat or sweater that covers them from neck to tail and around the abdomen.

Winter Pet Care 

• When you bathe your dogs in cold weather, make sure they are completely dry before taking them outside for a romp or walk.
• When walking your dogs during bad weather, keep them on leash. It’s easier for a dog to become lost in winter storm conditions — more dogs are lost during the winter than during any other season. (And don’t forget to microchip and put ID tags on your dogs and cats!)
• Leash your pets if you have frozen ponds, lakes or rivers nearby, as loose pets can break through ice and quickly succumb to hypothermia before trained ice-rescue personnel can arrive. Never try an ice rescue of a pet yourself — leave that to trained professionals.
• When you are working on housebreaking your new puppy, remember that puppies are more susceptible to cold than are adult dogs. In cold conditions or bad weather, you may need to opt for paper training your new pet rather than taking the pup outside.
• Keep your pets inside, both during the day and night. Just because they have fur doesn’t mean they can withstand cold temperatures.
• If dogs are left outside, they should have a draft-free shelter large enough to stand and turn around in, yet small enough to retain body heat. Use a layer of straw or other bedding material to help insulate them against the cold. Make sure the entrance to the shelter faces away from the direction of incoming wind and snow.
• Keep your cats indoors. Cats can freeze in cold weather without shelter. Sometimes cats left outdoors in cold weather seek shelter and heat under the hoods of automobiles and are injured or killed when the ignition is turned on. Banging loudly on the hood of your car a few times before starting the engine will help avoid a tragic situation. (This is true for wild animals in cold weather as well).
• When taking your pets out for a bathroom break, stay with them. If it’s too cold for you to stand outside, it is probably also too cold for your pets.
• Level Up Your Pet Parenting Skills With Our Free Guide!
• Unleash the ultimate pet parenting guide! Sign up now to receive our exclusive guide filled with expert advice from American Humane Society’s animal care and veterinary specialists. Discover essential training techniques, vital pet care tips, and much more.

Precautions for Outdoor Pets

• If your pet is outside during cold weather:
• Remember that staying warm requires extra calories. Outdoor animals typically need more calories in the winter, so feed them accordingly when the temperature drops. Talk to your veterinarian for advice on proper diet.
• Watch your pet’s outside fresh-water bowl. If it is not heated, you may need to refresh it more often as it freezes in cold weather.
• Salt and de-icers: Many pets like to go outside to romp and stomp in the snow, but many people use powerful salt and chemicals on their sidewalks to combat ice buildup. Thoroughly clean your pets’ paws, legs and abdomen after they have been outside, to prevent ingestion of toxic substances and to prevent their pads from becoming dry and irritated. Signs of toxic ingestion include excessive drooling, vomiting and depression.
• Ice and snow: When you let your pets in from a walk or a romp outside, make sure to wipe their paws and undersides — get those ice balls off as soon as possible, as they can cause frostbite. After being outside, check your pets’ paws, ears and tail for frostbite. Frostbitten skin usually appears pale or gray and can be treated by wrapping the area in a dry towel to gradually warm the area. Check with your veterinarian if you suspect frostbite.
• Use nontoxic antifreeze. Antifreeze is great-tasting to pets, but even a very small amount ingested can be deadly. Look for “safe” nontoxic antifreeze, consider using products that contain propylene glycol rather than ethylene glycol, and make sure all spills are cleaned up immediately and thoroughly. Contact your veterinarian immediately if you suspect your pets have ingested any antifreeze!

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AVMA Publications I Effectiveness of Multiwavelength Locked System laser therapy for calcinosis cutis in 3 dogs: a case series

Federica Gesuete, DVM, Filippo Ferri DVM, DECVIM, Sara Muñoz Declara DVM, DECVD, Luca Luciani DVM, Federica Tirrito DVM, DECVN, and Giordana Zanna DVM, PhD, DECVD

Abstract

Objective

To describe the clinical effects of photobiomodulation (PBM) therapy using a dual-wavelength near-infrared laser (Multiwave Locked System; Asa Srl) as adjunctive treatment in dogs with calcinosis cutis (CC).

Animals

3 client-owned dogs presented to 2 referral veterinary hospitals from 2022 through 2023 were included. Cases were identified retrospectively via medical record review. Inclusion criteria were clinical and cytological features consistent with CC and histopathological examination when available, diagnosis of hyperadrenocorticism (HAC) based on clinical signs and diagnostic workup, availability of sufficient clinical records and photographic documentation, and owner consent for PBM therapy. Photobiomodulation was applied following a standardized protocol in scanning mode with a 2-cm collimated handpiece (approx 3-cm2 spot): 3 sessions during week 1, every 72 hours in week 2, and then weekly with 4 J/cm2 at the first session and 2.03 J/cm2 thereafter.

Clinical Presentation

Included dogs were a 5-year-old male Labrador Retriever and an 8-year-old male English Bulldog with naturally occurring HAC and a 3-year-old female German Shepherd with iatrogenic HAC. All presented with dermatologic lesions compatible with CC (erythematous-crusted plaques, erosive-ulcerative lesions, and/or papules).

Results

2 dogs achieved complete lesion resolution with hair regrowth within 7 to 12 weeks; the third showed partial improvement. No adverse events occurred.

Clinical Relevance

Findings, although based on a limited number of cases, suggest a potential supportive role for PBM in the management of CC. Controlled studies are warranted to establish standardized treatment parameters and clarify its role in CC.

Calcinosis cutis (CC) is an uncommon condition characterized by the deposition of inorganic, insoluble minerals in the dermis, subcutis, or, rarely, epidermis. It generally involves the accumulation of cations (ie, calcium) and anions (ie, phosphate or carbonate), which are typically in equilibrium in the extracellular fluid within the collagen fibers and elastin of the dermis.1,2

Based on their etiology, 4 subtypes of CC have been described: dystrophic, metastatic, idiopathic, and iatrogenic. Dystrophic is the most common form of CC, often associated with hyperadrenocorticism (HAC), either naturally occurring or iatrogenic.1–3 Inflammation and hypoxia are believed to contribute to tissue damage, acting as a focal point for dystrophic calcification.4 Despite this, there is limited evidence of effective treatments for CC in veterinary medicine.5 Recently, fluorescent light energy biomodulation, a form of photobiomodulation (PBM) consisting of a topical component containing specific chromophores that require activation by a light-emitting diode lamp, has been demonstrated to be useful in managing pyoderma associated with CC in a dog.6

In general, experimental and clinical studies suggest that PBM may beneficially influence biological tissues by reducing inflammation and improving tissue microcirculation.7–8 Furthermore, some in vitro and in vivo studies9–10 have reported potential effects on bacterial growth, although evidence in veterinary clinical settings remains limited.

This case series describes the effectiveness of PBM using a high-power, dual-wavelength near-infrared (NIR) laser source (Multiwavelength Locked System [MLS] laser; ASA Srl) as adjunctive therapy in producing a regression of skin lesions associated with CC in 3 dogs.

Methods

Case selection

This descriptive case series included 3 client-owned dogs evaluated for dermatological lesions consistent with CC from 2022 through 2023. Cases were identified retrospectively by reviewing the medical records of 2 veterinary facilities in Italy: AniCura Istituto Veterinario di Novara (Granozzo con Monticello, Novara; cases 1 and 2) and AniCura Portoni Rossi (Zola Predosa, Bologna; case 3).

Inclusion criteria were (1) clinical presentation compatible with CC supported by cytological or histopathological findings when available, (2) diagnosis of HAC, (3) availability of sufficient clinical records and photographic documentation, and (4) owner consent for adjunctive PBM therapy. Exclusion criteria included insufficient medical documentation or use of a nonstandardized PBM protocol.

All procedures were performed with owner informed consent and in compliance with patient welfare. No sedation was required for diagnostic or therapeutic procedures.

Photobiomodulation therapy was standardized across cases using a high-power, dual-wavelength NIR laser with 2 different wavelengths within the NIR spectrum: 808 nm in continuous or frequency-modulated mode and 905 nm in pulsed mode. Treatments were applied in scanning mode with a 2-cm collimated handpiece (approx 3-cm2 spot size). Each affected area was divided into multiple sections to ensure uniform dosing. The first session delivered 4 J/cm2 (“infected wound” mode), whereas subsequent sessions delivered 2.03 J/cm2 (“wound” mode). Sessions were performed 3 times during week 1, every 72 hours during week 2, and then weekly thereafter. Cases 1 and 3 received PBM for approximately 12 weeks and case 2 for 7 weeks.

Concomitant therapies

Dogs received standard management for HAC. Other therapies included topical antiseptics and systemic or topical antimicrobials when cytology confirmed secondary superficial pyoderma. Routes, dosages, and administration frequencies are reported in the case descriptions.

Safety considerations

Protective goggles were worn by the operator and handlers throughout all PBM sessions. Treatments were performed without sedation, respecting patient behavior and welfare. No adverse events were observed during therapy.

Follow-up

Monitoring consisted of serial clinical examinations and photographic documentation. Follow-up duration was determined by lesion resolution or until PBM treatment was discontinued.

Statistical analysis

No formal statistical analyses were performed due to the descriptive nature and limited number of cases. Data were compiled and summarized using Excel 365 (Excel 365; Microsoft Corp, Version 16.89) to organize clinical records, images, and follow-up information.

Results

A total of 3 dogs were identified during the study period, and none were excluded after eligibility screening. The diagnostic approach varied among cases, reflecting real-world clinical practice.

Case 1

A 5-year-old intact male Labrador Retriever was referred with a 1-month history of obtunded mental status and decreased appetite. The owners reported polyuria and polydipsia as well as episodes of epistaxis over the previous few months. On physical examination, the patient showed marked lethargy, diffuse cutaneous lesions, and an increased body condition score of 7/9. Dermatological examination revealed the presence of 2 symmetrical erythematous, crusted-plaque lesions on the temporal region; a large, crusted plaque on the neck; and alopecia associated with 2 erythematous, crusted plaques across the dorsal thorax and dorso-lumbar region. Microscopic examination of plucked hairs showed hair shafts in the telogen phase. Multiple skin scrapings were negative for ectoparasites. Cytology of the plaques revealed a variable number of macrophages and neutrophils as well as the presence of extracellular and intracellular cocci and the presence of amorphous crystalline deposits.

Complete bloodwork and serum biochemistry showed mild lymphopenia (0.99 K/μL; reference range, 1.06 to 4.95 K/μL), marked increases in ALP (1,800 U/L; reference range, 14 to 147 U/L), and moderately elevated ALT (327 U/L; reference range, 25 to 122 U/L,), GGT (31 U/L; reference range, 2 to 13 U/L), and glutamate dehydrogenase (56 U/L; reference range, 1 to 18 U/L). Urine specific gravity was 1,022, with a urinary protein-to-creatinine ratio of 2.42 (reference range, < 0.5). Abdominal ultrasound revealed bilateral adrenomegaly and hepatomegaly, with the liver being diffusely hyperechoic.

Based on these results, naturally occurring HAC with secondary CC was suspected. To confirm the diagnosis, the following tests were recommended: the low-dose dexamethasone suppression test and skin biopsy under local anesthesia for dermatopathological examination. Additionally, to rule out infectious diseases, bacteriological and mycological examinations from deep skin tissue were also performed. The low-dose dexamethasone suppression test showed a lack of suppression at any time points (before: 3.7 µg/dL, range 1.0 to 6.0 µg/dL; 4 hours after: 3.5 µg/dL, range 0 to 1.4 µg/dL; 8 hours after: 2.7, range 0 to 1.4 µg/dL).

Skin biopsy specimens were collected from the plaque lesions on the neck and on the dorso-lumbar region. Histological examination showed severe and diffuse orthokeratotic hyperkeratosis of the epidermis, with mild-to-moderate irregular hyperplasia. Multifocal deposits of amorphous, crystalline, and deeply basophilic material were observed in the mid- and deep dermis, consistent with dermal mineralization. These mineralized structures were surrounded by a marked accumulation of activated fibroblasts and macrophages and occasionally accompanied by multinucleated giant cells. Both bacteriological and mycological examinations from deep skin tissue were negative.

To investigate the abnormal mental status, and considering the results of the previous examinations, an MRI scan (1.5 Tesla; SIGNA Creator; General Electric) of the head was performed. The scan revealed a large space-occupying lesion (measuring 26 X 26 X 24 mm) in the sellar region, which extended dorsally and exerted clinically important compression on the surrounding brain structures, including the optic chiasm, hypothalamus, and thalamus. The pituitary-to-brain ratio was > 0.31. The MRI scan findings were primarily compatible with a pituitary tumor, and a pituitary macroadenoma was suspected. A final diagnosis of pituitary-dependent hypercortisolism, due to pituitary macroadenoma, with cutaneous CC and secondary superficial bacterial infection, was proposed.

Treatment with trilostane (Vetoryl) was administered orally at a dose of 0.7 mg/kg every 12 hours, resulting in a rapid improvement of clinical signs. Additional treatments, such as radiation therapy and cabergoline, were declined by the owners. Due to the extensive skin lesions, topical therapy with chlorhexidine and systemic antibiotic therapy with amoxicillin-clavulanic acid (Synulox) administered orally at a dose of 20 mg/kg twice daily were started.

Photobiomodulation therapy was proposed as an additional treatment to address the dermatological lesions caused by mineral deposition, following the protocol in the flowchart (Figure 1). Owner informed consent was obtained, and all procedures were based on respecting patient behavior and welfare. The operator wore protective goggles throughout the procedure to ensure safety. After 14 days of initiating PBM therapy, antibiotic treatment was discontinued as serial cytology evaluations confirmed the improvement of superficial pyoderma. From that point onward, the only treatments were PBM therapy and topical chlorhexidine.

Figure 1

A class IV laser (Multiwave Locked System; Asa Srl) was used in all 3 cases. Three sessions were performed during the first week, followed by treatments every 72 hours in the second week and weekly sessions thereafter. The treatment was conducted in scanning mode using a collimated-lens handpiece (2-cm diameter, 3-cm2 spot area). In cases 1 and 3, sessions continued for a total of 12 weeks, whereas treatments were conducted for a total of 6 weeks in case 2. The operator wore protective goggles during all sessions to ensure safety. The affected areas were divided into multiple sections, with each section receiving the same dosage of 4 J/cm2 (“infected wound” mode) during the first session, followed by a dosage of 2.03 J/cm2 (“wound” mode) in subsequent sessions. The flowchart illustrates the different settings using a reference area of 100 cm2.

Citation: American Journal of Veterinary Research 2025; 10.2460/ajvr.25.09.0314

Figure 2

Wound healing progression of crusted plaque-like lesions on the neck of case 1, a 5-year-old male Labrador Retriever, treated with adjunctive PBM therapy using a dual-wavelength near-infrared laser (808 and 905 nm; Multiwave Locked System; Asa Srl). Images were taken at time (T)-0 (baseline), T45, T60, and T90 days. At T0, lesions exhibit crusting and marked erythema. By T45 and T60, crusting and inflammation are visibly reduced. At T90, lesions are resolved and hair regrowth is evident. These images illustrate the progressive effect of PBM on lesion resolution and tissue repair. Study period: 2022 through 2023.

Citation: American Journal of Veterinary Research 2025; 10.2460/ajvr.25.09.0314

Figure 3

Wound healing progression in the right temporal region of case 1, a 5-year-old male Labrador Retriever, treated with adjunctive PBM therapy using a dual-wavelength near-infrared laser (808 and 905 nm; Multiwave Locked System; Asa Srl). Images were taken at different time points during treatment: T0, T45, T60, and T90 days. At T0, the temporal area shows crusts, marked erythema, and inflammation. By T45, crusts are reduced while erythema and inflammation persist. At T60, inflammation is markedly reduced, with initial hair regrowth visible. At T90, healing is complete, with full hair regrowth and a normal appearance of the treated area. The images illustrate the gradual and effective impact of PBM on tissue repair and regeneration in this case. Study period: 2022 through 2023.

Citation: American Journal of Veterinary Research 2025; 10.2460/ajvr.25.09.0314

Six months after diagnosis, the dog was reevaluated for anorexia and worsening of neurological signs, presenting disorientation, head pressing, circling, and pain upon palpation of the cervical column. A pain treatment with tramadol (3 mg/kg) and paracetamol (15 mg/kg) was started, but 2 weeks later the owner opted for euthanasia due to the poor evolution of the dog’s clinical conditions.

Case 2

A 3-year-old intact female German Shepherd was referred for a 2-week history of an erosive-ulcerative lesion on the neck. Topical treatment with streptomycin (q 12 h) was initially prescribed by the referring veterinarian for 10 days, but no improvement was observed. The dog had a previous history of primary immune-mediated nonerosive polyarthritis and meningomyelitis of unknown origin diagnosed through a comprehensive workup, including a total body CT scan, fine-needle aspiration cytology of multiple joints, and an MRI study of the vertebral column with cerebrospinal fluid analysis. Blood screening for vector-borne diseases (including Ehrlichia spp, Leishmania spp, Borrelia burgdorferi, Babesia canis, Anaplasma spp, Dirofilaria immitis, and Hepatozoon spp) ruled out infectious diseases.

After the initial diagnosis of immune-mediated disease, the dog had been receiving prednisolone therapy (1.5 mg/kg once daily) for 2 months.

At the time of presentation to the dermatology service, the immune-mediated condition appeared to be in remission. The owners reported that, following glucocorticoid therapy, the dog had developed severe polyuria, polydipsia, and polyphagia.

During physical examination, the dog exhibited mild lethargy, a distended abdomen, and generalized muscle atrophy. Dermatological evaluation revealed an 8 X 8-cm erosive-ulcerative lesion on the dorsal neck, along with 2 firm, white-coated lesions on the lateral tongue and perilabial region.

The collateral diagnostics performed included microscopic examination of plucked hairs, which showed follicles predominantly in the telogen phase, and multiple superficial and deep skin scrapings, which were negative for parasites. Cytology of the erosive-ulcerative lesions demonstrated abundant amorphous, basophilic material with a few crystal-like structures, neutrophils, macrophages, multinucleated giant cells, and extracellular cocci.

Blood analyses were performed and revealed marked increases in ALT (1,125 U/L), ALP (1,081 U/L), and glutamate dehydrogenase (110 U/L), with mild elevations in AST (117 U/L) and GGT (46 U/L). Further diagnostic tests, including dermatopathology, bacteriology, and mycology examination, were proposed but declined by the owner.

Based on the clinical history, cytological findings, and bloodwork, a diagnosis of CC secondary to iatrogenic HAC, complicated by a superficial bacterial infection, was made.

Glucocorticoid therapy was gradually tapered and discontinued over a 4-week period to minimize the relapse risk of the immune-mediated disease. Topical gentamicin (q 12 h) was initiated, and PBM therapy was applied exclusively to the dorsal neck lesion according to the protocol outlined in Figure 1.

Owner informed consent was obtained, and all procedures respected patient welfare. The operator wore protective goggles throughout treatment. Topical therapy was discontinued after 10 days, following serial cytological evaluations showing progressive improvement of superficial pyoderma. After 25 days of treatment, an > 80% reduction in lesion size was observed, and complete clinical resolution of the dorsal neck lesion was achieved 7 weeks after initiation of laser therapy.

Case 3

An 8-year-old intact male English Bulldog was referred for a 2-month history of progressive polyuria and polydipsia and dermatological lesions. On physical examination, the dog was panting, and a distended abdomen was noted. Dermatological examination revealed erythematous plaques with crusts on the dorsal neck region along with several erythematous papules on the left shoulder area, some of which were confluent and crusted.

Microscopic examination of plucked hairs revealed a predominantly telogen phase. Multiple superficial-to-deep skin scrapings were negative for ectoparasites. Cytological examination of the lesions revealed a mixture of neutrophils, macrophages, and a few multinucleated giant cells around some crystal-like structures. Additionally, cocci were observed, with both intracellular and extracellular distribution. The CBC revealed an increased platelet count (761 X 103/μL; reference range, 150 to 500 X 103/μL) and mild lymphopenia (800 K/μL; reference range, 900 to 4,000 K/μL). Serum biochemistry showed elevated ALP (551 U/L; reference range, 14 to 147 U/L), mildly increased ALT (113 U/L; reference range, 15 to 65 U/L) and GGT (16.7 U/L; reference range, 2 to 13 U/L). Urine specific gravity was 1,004, with a urinary protein-to-creatinine ratio of 12.22 (range, < 0.5).

The ACTH stimulation test (pre-ACTH cortisol: 8.4 µg/dL, range 1 to 4.8 µg/dL; post-ACTH cortisol: 30.80 µg/dL, range 6 to 18 µg/dL) was positive for hypercortisolism. A total body CT scan revealed a 7.3 X 13 X 8-mm pituitary mass in the sellar region, extending dorsally to the basisphenoid, with a pituitary-to-brain ratio > 0.31, hepatomegaly, and bilateral adrenomegaly. A pituitary macroadenoma was considered the most likely diagnosis. The owner declined other diagnostic investigations, such as dermatopathological, bacteriological, and/or mycological examinations of deep skin tissue.

Based on the patient’s history, the type and distribution of the lesions, and the results of the investigations, a diagnosis of macroadenoma with secondary CC and secondary bacterial infection was made.

Treatment with trilostane (Vetoryl; 0.6 mg/kg, q 12 h) was started; to treat the CC and the concurrent secondary bacterial infection, topical therapy with chlorhexidine and systemic therapy with amoxicillin-clavulanic acid (Synulox; 20 mg/kg twice daily) were started. Photobiomodulation therapy was also introduced following the protocol in the flowchart (Figure 1). After 10 days of combined therapy, the antibiotic treatment was discontinued as the pyoderma improved. Owner informed consent was obtained, and all procedures were based on respecting patient behavior and welfare. The operator wore protective goggles throughout the procedure to ensure safety. Clinical improvement of the dermatological clinical signs was observed from the eighth PBM session, with significant progress noted by the sixth week. However, some lesions remained partially improved and persisted at week 12, and complete resolution was not achieved.

Three months after the initial presentation, the dog developed severe dyspnea and 2 episodes of collapse; an acute pulmonary thromboembolism was suspected. The owners declined further diagnostic tests, and compassionate euthanasia was performed.

Discussion

To the best of the authors’ knowledge, this is the first report to describe the use of MLS for the treatment of CC in 2 cases with naturally occurring HAC and in 1 with iatrogenic HAC.

There are no broadly effective treatments for CC owing to the lack of a complete understanding of the mechanisms involved. In human medicine, a variety of treatment modalities are used based on the type, severity, and number of lesions. These include pharmacological therapies, such as antibiotics, immunosuppressants, bisphosphonates, colchicine, IV immunoglobulins, and other biologic therapies. Additionally, nonpharmacological treatments, such as surgical excision, shockwave therapy, and carbon dioxide laser therapy, are also employed.11 Similarly, in veterinary medicine there is no standardization of therapies for CC, and many treatments are supported by limited case reports or rely on the clinical expertise of practitioners. For example, there is one case report12 that describes a dog with CC locally treated with DMSO with a resolution of wounds in 3 months. Dimethyl sulfoxide is known for its high skin-penetrating and anti-inflammatory properties, but its efficacy remains anecdotal as do the mode and frequency of application. The effectiveness and safety of minocycline, a bacteriostatic antibiotic in the tetracycline family used for CC in human medicine, has also been assessed in 5 dogs, with a clinical resolution observed in 4 of 5 cases in 6 to 12 weeks. It is thought that minocycline reduces inflammation, chelates calcium and iron, and influences angiogenesis beyond its antibacterial properties.5 Finally, an accelerated improvement in lesions treated with fluorescent light energy compared to those not exposed and treated with DMSO and chlorhexidine was recently documented in a dog with CC.6

In general, PBM is a nonthermal process that utilizes endogenous chromophores to promote photophysical and photochemical reactions at various biological levels.13 This process involves light in the red or NIR spectrum, with specific wavelengths ranging from 600 to 1,100 nm. Lasers, light-emitting diodes, and various other light-emitting devices with class 3B and class 4 lasers are commonly employed as they emit monochromatic, coherent, and collimated light, enabling precise and targeted treatment of specific tissues.14 Although the exact mechanism of PBM is not fully understood, it could depend on the target and type of cell being modulated. It is highly likely that photons are absorbed by cytochrome c oxidase, which is in the inner membrane of mitochondria. Cytochrome c oxidase absorbs light in the range of 500 to 1,100 nm, becomes activated, and dissociates from nitric oxide, binding to oxygen. This results in improved electron transport and ATP production and the triggering of several pathways that lead to cell proliferation and tissue repair.15,16 On this basis, the use of PBM has been reported for the management of musculoskeletal disorders and neurological diseases, to relieve pain, and, especially, for treatment of wounds given its noninvasive nature and its minimal side effects in both human and veterinary medicine.17–25

However, the efficacy of PBM on target tissues also depends on treatment parameters, light source, wavelength, density, type of energy emission (continued or pulsed), type of lasers, and duration and frequency of laser application.26 Although there have been several in vivo studies,25 results in veterinary medicine are inconclusive due to the lack of standardization of parameters under different clinical conditions. In this case series, we introduced a more standardized approach by following a specific protocol.

The laser used was the MLS laser, a class 4 therapy system emitting NIR beams at 2 wavelengths within the NIR spectrum: 808 nm in continuous or frequency-modulated mode and 905 nm in pulsed mode. The beams are spatially overlapped and synchronized during treatment. The laser has an average maximum power of 3.5 W and a peak power of 270 W.

With the treatments detailed here, complete remission of CC was achieved in 2 of the 3 cases in 7 to 12 weeks. In the case associated with iatrogenic HAC, lesions resolved after approximately 7 weeks—shorter than the 12 weeks reported by Huang et al27 following corticosteroid withdrawal alone. In the dog affected by naturally occurring HAC, lesion resolution occurred after 12 weeks, consistent with previously reported cases treated with minocycline or DMSO. It is likely that additional treatment sessions in the third case would have resulted in complete clinical resolution.

It was hypothesized that these therapeutic effects could be due to multifactorial mechanisms. Based on previously reported effects of PBM, it is possible that laser therapy contributed to modulating inflammation7–29 and supporting tissue repair, enhancing microcirculation,30 reducing local edema,31 and promoting a more favorable environment for healing and resorption of calcium deposits.

Second, the superficial bacterial infections commonly associated with CC lesions also play a critical role in the disease progression, often complicating the healing process. The potential antibacterial effect of PBM,32 along with its role in impacting the skin microbiome as recently documented,33 may have contributed to reducing the bacterial load and shortening the duration of antibiotic use, thereby promoting tissue regeneration and helping to alleviate inflammation.

These observations suggest that PBM may have contributed to accelerated lesion healing. However, due to the small number of cases and the absence of controls, its specific contribution to the clinical outcome cannot be determined. While these findings are descriptive and cannot establish efficacy, PBM may represent a promising adjunctive approach for managing CC in dogs, warranting further investigation in larger, controlled studies.

https://avmajournals.avma.org/view/journals/ajvr/aop/ajvr.25.09.0314/ajvr.25.09.0314.xml

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AVMA NEWS I American Bar Association highlight link between domestic violence, animal cruelty

Experts say the biggest red flag of potential animal abuse is inconsistent medical history

Published on November 19, 2025

The AVMA and the American Bar Association (ABA) have partnered to draw attention to the link between violence against people and animals. 

Dr. Amanda Bisol, who represents District 1 on the AVMA Board of Directors and has a law degree, and Dr. Kendall Houlihan, associate director in the AVMA Animal Welfare Division, participated in a webinar, “Protecting People and Pets from Domestic Violence,” on October 22.

Spotting the signs

Dr. Bisol highlighted the importance of recognizing signs of animal maltreatment in clinical settings, such as unexplained injuries and a general lack of care or history that “just doesn’t add up.” 

“The biggest red flag is an inconsistent [medical] history,” Dr. Bisol said. Another sign that is not as common are multiple injuries on the same animal that are different ages—for example, if an X-ray of a new fracture shows a healing fracture.

 It’s important to be aware of how domestic violence and animal maltreatment can be interconnected, Dr. Bisol said, because sometimes, veterinarians may be the only ones to see the potential signs of an issue in a home. She also urged documenting a suspicious case with additional detail, including pictures, as such veterinary records may be valuable evidence if the case is investigated.

 The sessions include an overview of how to identify signs of domestic violence and animal abuse or neglect and show how the two may be connected. Presenters also discuss how to access resources that support survivor decision-making and how to foster collaboration with local organizations and agencies that can help protect both survivors and their pets.

Collaborative effort

This collaboration between the AVMA and ABA comes after the law association adopted Resolution 504 earlier this year, urging all levels of government “to enact legislation and/or support judicial processes that protect individuals by protecting their pets in family law and civil restraining order proceedings.”

“The aim of this collaboration is to highlight the roles and responsibilities of different professionals and how we may more effectively interact with and support each other and our communities,” said Dr. Houlihan. 

AVMA policy on “Animal Abuse and Animal Neglect” states that prompt disclosure of abuse is necessary to protect the health and welfare of animals and people.

While disclosure is important, “it is not the veterinarian’s task to determine if the maltreatment meets the enumerated elements of a crime; this is the duty of the investigating authority and the criminal justice system,” according to the AVMA’s “The Veterinarian’s Framework for Identification and Response to Suspected or Known Animal Maltreatment,” a free resource for veterinary professionals.

Veterinary social workers are uniquely dedicated to tending to the human needs that arise from relationships between humans and animals. Accordingly, Dr. Bethanie Poe, associate director of education and training for the University of Tennessee’s Center for Veterinary Social Work, also provided her expertise to the sessions.

Guiding future efforts

Animal cruelty has historically been considered an isolated issue that is not indicative of other violence. However, “recent research shows a well-documented link that it is a predictive or co-occurring crime with violence against humans (including intimate partners, children, and elders) and is associated with other types of violent offenses,” according to a 2021 Federal Bureau of Investigation Law Enforcement Bulletin. “Increased awareness of this linkage and a collaborative approach to these investigations strengthens the identification and reduction of such crimes.”

One result of the growing awareness of the link between animal and personal violence is greater consideration of what to do with a pet when the owner enters a domestic violence shelter.

For example, a paper published in the May 2024 issue of JAVMA described the creation of a safekeeping program for pets owned by domestic violence victims.

Dr. Hillary L. Pearce and others found that involving at least one veterinary practice was integral, “as most pets entering the program needed vaccination, testing for infectious disease, and/or parasiticide prevention before being placed into foster homes. The veterinary practice also served as a crucial temporary holding facility until pets could be matched into suitable foster homes.”

Recognizing that a variety of professionals engage with people and pets affected by domestic violence, future collaborations may add the perspectives of law enforcement and judges, who also work to support the human-animal bond in challenging circumstances.

https://www.avma.org/news/avma-american-bar-association-highlight-link-between-domestic-violence-animal-cruelty?utm_source=delivra&utm_medium=email&utm_campaign=todays-headlines-news

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AVMA I News Normalize pet nutrition conversations at every veterinary visit

Purina handbook explores pet nutrition across the lifespan with proactive and practical recommendations

Published on November 17, 2025

As pet obesity rates continue to climb nationwide, nutrition is top of mind for pet owners and veterinarians alike.

The Purina Institute Handbook of Canine and Feline Well-Pet Nutrition, launched in August, provides evidence-based recommendations for veterinary care teams to help them prioritize pet nutrition in practice. The handbook is available for free with a sign-up for scientific communications from the institute.

The handbook cites a May 2023 Purina Institute survey, which showed 96% of pet owners said they trust their veterinarian for pet nutrition advice, but only 22% of veterinary professionals have proactive conversations about nutrition at most visits.

“Nutrition also brings the pet pleasure, positively reinforces the human-animal bond, and helps owners express love to their pets,” according to the introduction. “As we continue to recognize the integral role that pets play in our lives, it is essential to acknowledge the importance of proper nutrition in ensuring their health and longevity.”

Pet nutrition

Developed with contributions from 54 experts across 20 countries, the 322-page handbook covers nutrient fundamentals in small animals, specialized nutrition guidance by life stage, proactive nutrition recommendations for various health benefits, and other practical tools. 

For example, Dr. Yuki Okada, a board-certified veterinary nutritionist in San Francisco, in the guide calls protein “undoubtedly the most critical macronutrient in the nutrition of both dogs and cats, serving as the primary source of amino acids and nitrogen for various physiological functions.”

 The recommended protein intake is approximately 4 g/kg of body weight for senior dogs and about 5.2 g/kg for senior cats, according to the handbook, unless kidney disease necessitates certain restrictions.

 Cats, as obligate carnivores, have significantly higher protein needs than dogs to maintain a constant state of gluconeogenesis that meets energy demands.

 And senior pets may need up to 50% more protein than younger adults to counteract age-related muscle loss.

Overall, geriatric pets experience physical, functional, and metabolic changes that are still amenable to nutritional intervention to improve health and quality of life. A cohesive framework of nutritional prioritization and planning can aid in managing comorbidities in geriatric pets, according to the guide.

 The section on proactive strategies covers the impact nutrition has on everything from oral and gastrointestinal health to joint, behavioral, and urinary health.

 In addition, a table of ingredients commonly found in dental diets, treats, and chews, such as folic acid or polyunsaturated fats, shows the respective modes of action.

Client conversations

The handbook calls for veterinary care teams to have “a well-stocked communication skill toolkit” on hand to equip conversations with clients about pet nutrition.

Talk model 

“Clients want to be partners in their pet’s veterinary care,” the handbook states. “Clients that understand the beneficial outcome for their pet (the ‘why’ behind recommendations) are more likely to adhere to plans of care.”

Or, talking about pets’ skin and coat health, an overall health indicator, is also a great conversation starter.

The section also addresses some common communication challenges and how to navigate them, including client resistance, skepticism, and the perception that a discussion on pet foods is driven by financial motivations and wanting to “make a sale.”

 Veterinary professionals need to be prepared to confront and correct misinformation, as well as disinformation, differentiated as “false or incorrect information that is shared with an underlying intent to mislead.”

Care teams can counter misinformation by proactively discussing and providing resources on common nutritional myths. This is known as inoculation or “prebunking” with “cognitive antibodies,” with the aim of making pet owners more resilient to nutritional misinformation in the future.

Practical tools

Beyond nutritional science, the handbook offers 25 “Practical Tools,” including a fecal scoring chart with pictures and descriptions of different stools.

It also includes guidance on feeding “finicky” felines, managing cat allergens through nutrition, and selecting products marketed as supplements, as well as scoring charts for assessing body and muscle condition.

 “It has been reported that pet owners tend to underestimate the body condition of their pet, emphasizing the importance of equipping every team member to perform and teach body condition scoring (BCS) and muscle condition scoring (MCS) at each visit,” writes Ashley Self, assistant director of veterinary nutrition at Texas A&M University College of Veterinary Medicine and Biomedical Sciences. “By involving the owners in the process of obtaining a body weight and estimating BCS and MCS, veterinary teams can identify trends that support proactive management while also enhancing the pet owner’s understanding of what constitutes a healthy body weight, BCS, and MCS.”

 Veterinarians should also educate pet owners on available tools like wearable devices, litter box monitoring systems, and mobile applications that support at-home monitoring for more proactive and preventive care.

“Nutritional science has evolved significantly, and there are many facets to consider in a well-pet diet—not just from the pet’s perspective, such as life stage, activity level, and body condition, but also the owner’s perspective—their lifestyle, budget, and preferences,” said Natalia Wagemans, MD, the institute’s global head, in an August 28 press release. “This resource simplifies the process of making informed recommendations and can be a vital tool for veterinary professionals to both facilitate nutrition conversations with their clients and provide informed responses to questions.”

https://www.avma.org/news/normalize-pet-nutrition-conversations-every-veterinary-visit?utm_source=delivra&utm_medium=email&utm_campaign=todays-headlines-news

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AVMA News I FDA reminds pet food makers that raw ingredients pose risk of exposure to H5N1

Published on November 14, 2025

Federal agencies are tightening regulations on raw pet food ingredients due to the risk of highly pathogenic avian influenza (type A H5N1) transmission. 

Recent investigations have pointed to raw meat, specifically poultry, and unpasteurized milk as a source of infection for cats, both domestic and wild, which can experience severe illness or death from infection with the virus. 

Dogs can also contract H5N1, although they usually exhibit mild clinical signs and low mortality. 

“During the fall migratory season, H5N1 detections typically increase throughout the United States in wild birds, with potential spread to commercial and backyard poultry flocks,” according to the Food and Drug Administration (FDA) Center for Veterinary Medicine. 

Suspected or verified sources of  highly pathogenic avian influenza type A H5N1 infecting cats include unpasteurized cow’s milk and raw poultry products.

With that in mind, on September 30, the agency issued a reminder to pet food manufacturers that H5N1 is a “known or reasonably foreseeable hazard” when using uncooked or unpasteurized ingredients. 

Under the agency’s Food Safety Modernization Act Preventive Controls for Animal Food requirements, animal food businesses must conduct a reanalysis of their food safety plan when the FDA determines it is necessary to respond to new hazards and developments in scientific understanding. 

Earlier this year, the FDA determined that food safety plans of manufacturers that specifically use uncooked or unpasteurized materials from poultry or cattle should include H5N1 as a potential hazard and implement preventive controls as needed. This could include seeking ingredients from healthy flocks or herds, taking processing steps such as heat treatment, or implementing a supply chain–applied control to provide assurance that ingredients used in animal food do not come from H5N1-infected animals. 

“Manufacturers that implement a preventive control for the H5N1 hazard as a result of their reanalysis will be taking an important step toward protecting cat and dog health and helping to prevent spread of H5N1,” according to the FDA.

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Taylor & Francis Online I Serum Onconeural Antibodies in Dogs and Cats for Early Diagnosis of Cancer

Marianna Agassandian & Khristofor Agassandian

Published online: November 12, 2025

Abstract

Cancer is one of the leading causes of death in dogs and cats worldwide, and effective early detection techniques and reliable therapies are still lacking. Given the high demand for early cancer detection and differentiation in veterinary diagnostics, we developed and validated a new diagnostic approach to assess onconeural antibodies, also known as high-risk antibodies, in dog and cat blood serum samples. We determined the presence of systemic onconeural/high-risk (ONHR) antibodies, their suitability for early cancer diagnostics, and the feasibility of differentiating various malignancies. Our results identified several ONHR antibodies in 0.1 mL of specimens by the immunoblot-based technique, which was confirmed by indirect immunofluorescence assay. The diagnostic performance for detecting identified antibodies has demonstrated >95% sensitivity in dogs, >93% sensitivity in cats, as well as >97% specificity in dogs, and >95% specificity in cats. Thus, our data provide the first proof-of-principle that onconeural antibodies can be detected in dogs and cats, and their identification in serum might serve as a new tool for early cancer diagnosis.

Introduction

Malignant tumors in companion animals are a significant problem affecting the lives and well-being of pets and their owners. According to the Veterinary Cancer Society, cancer is the leading cause of death in 47% of dogs, especially elderly dogs, and 32% of cats.Citation1 Dogs develop cancer at almost the same rate as humans.Citation2 Cancer detection at the earliest stage may significantly improve the efficacy of the treatment and survival. Sensitive and specific methods for cancer screening can reduce mortality and improve the quality of life of affected animals.

Recently, two advanced techniques adapted from human cancer diagnostics have been implemented into veterinary medicine. The OncoK9 “liquid biopsy”, based on next-generation sequencing, could only differentiate hematological malignancies, required large blood volumes, was costly, and was discontinued from commercial use.Citation3

The second, Nu.Q test, measures plasma nucleosome concentration to predict certain cancers but provides only positive/negative results and can be provoked by inflammation, trauma, or other diseases.Citation4

To address these diagnostic limitations, we focused on antibody biomarkers, widely used in human medicineCitation5 but still limited in veterinary diagnostics due to a lack of development and standardization.Citation6–11 Canine and human cancers share biological similarities,Citation12 making this approach promising. We investigated onconeural antibodies, produced against neuronal proteins aberrantly expressed in tumor cells. These antibodies are linked to paraneoplastic neurological syndromes (PNS), which may precede cancer diagnosis.Citation13 Although not always directly pathogenic, they are valuable diagnostic markers.Citation14

Onconeural antibodies target intracellular or extracellular (membrane-bound) neuronal or glial proteins. Antibodies against intracellular proteins are more specific for malignancy rather than neurological syndromes and considered “high-risk”,Citation14,Citation15 while extracellular-directed antibodies are more closely tied to neurological diseases.Citation16 Sometimes, multiple antibodies coexist and are associated with the same cancer or PNS.Citation17 Paraneoplastic disorders are diagnosed in human patients with cancer, but there is a lack of knowledge about these diseases in animals. Even though these syndromes have been reported in dogs and cats, these diseases are usually diagnosed too late after the identification of cancer.

Since ONHR antibody formation usually precedes cancer, its early detection can predict malignancy before clinical symptoms, aiding timely treatmentCitation18–21 and better outcomes for pets.Citation22–24 Thus, serological detection of ONHR antibodies represents a convenient diagnostic method for early cancer detection and differentiation.

Depending on the type of malignancy, tumor cells may express intracellular proteins/antigens such as amphiphysin, CV2/CRMP5, Ri/NOVA1, Yo/CDR2, Hu/ELAV, recoverin, SOX1, titin, ZIC4, GAD65, and Tr/DNER that are normally restricted to the nervous system.Citation25–35 These antigens can induce specific antibody formation before tumors are symptomatic. Altered expression, mutations, or posttranslational modifications can create neoantigens, provoking immune responses.Citation36

As illustrated in many studies, between 50 and 90% of tumor-associated proteins/antigens in the human body acquire a variety of modifications that alter immunologic processing and presentation.Citation37 Thus, the modified self-antigens and neoantigens can be recognized as non-self-antigens by the immune system and promote onconeural antibody formation in the blood of patients with different types of tumors and have the potential to be an early sign of cancer. According to the literature, ONHR antibodies were detected in more than 90% of cases with underlying cancer within a few years of the study.Citation38

Unfortunately, in veterinary medicine, only a few antibodies to neuronal proteins have been identified.Citation39–45 In our study, we validated ONHR antibodies in sera of cancer-bearing dogs and cats, confirming their stability and strong association with malignancies. These findings support their use as novel, noninvasive biomarkers for early cancer detection and malignancy-associated neurological diseases in pets.

Materials and Methods

Ethics Statement

Ethical approval was not required for this study, as it used de-identified residual serum samples submitted to Pet Preferred Diagnostics for research purposes and after routine diagnostics, with no additional collection or animal interventions.

Inclusion Criteria

The validation study was conducted on a total of 202 dogs and 50 cats, including 76 presumably healthy dogs and 20 presumably healthy cats with medical records from participating veterinary clinics and the National Institute of Health blood bank. The records included patient information such as age, sex, breed, neuter status, clinical history, and examination details.

Serum samples were collected from dogs and cats with confirmed or suspected malignancies at the time of validation, as well as animals with specific neurological symptoms. Sera obtained from presumably healthy dogs and cats, based on physical examination and clinical history, were also included in the validation study. Animals with conditions such as chronic infections were excluded from this study.

Animal Samples

Serum samples (0.05–0.5 mL) from animals (dogs and cats) with confirmed, suspected cancer, and presumably healthy were prepared from blood using VACUETTE tubes with serum separator. After 30–45 minutes at room temperature (which allows blood to clot), the tubes containing the collected blood were centrifuged at 2000–2500 RPM for 20 minutes to separate the serum. Sera were then transferred to Eppendorf tubes labeled with the patient’s name and date of sample collection and shipped to Pet Preferred Diagnostics laboratory to be tested for the presence of onconeural antibodies.

Routine screening for the presence of ONHR antibodies such as anti-Hu, -Yo, -CV2, -Ri, -Tr, -ZIC4, -SOX1, -GAD65, -recoverin, -amphiphysin, and anti-titin (11 ONHR antibodies) was performed by immunoblot and confirmed by indirect immunofluorescence technique (IIFT) using monkey tissue slides.

Protein Sequence Comparison

UniProt Knowledgebase (UniProtKB) has been used for the analysis of ELAV/HuD (ELAV-like protein 4), CDR2/PCD17 (cerebellar degeneration-related protein 2), CRMP5/DPYSL5 (dihydropyrimidinase-related protein 5), NOVA1 (RNA binding protein), DNER/BET (Delta/Notch-like epidermal growth factor-related receptor), ZIC4 (Zinc finger protein), SOX1 (transcription factor protein), GAD65 (glutamate decarboxylase 2), RCVRN/RCV1 (recoverin/cancer-associated retinopathy protein), AMPH/BIN1 (amphiphysin/bridging integrator1/Myc box-dependent-interacting protein 1), and TTN (Titin/Connectin) human, canine, and feline protein sequences. Human, canine, and feline protein sequences were aligned using Clustal Multiple Sequence Alignment. A sequence similarity search query was submitted in the FASTA format.

Immunoblot-Based Assay

Serum samples from dogs and cats were tested using the commercial immunoblot kit (EUROLINE Neuronal Antigens Profile 72 (IgG), DL 1111–1601-72 G; Euroimmun, Lübeck, Germany). Immunoblots were performed on the EUROBlotOne system (Euroimmun). The nitrocellulose test strips with immobilized amphiphysin, CV2, Ri, Yo, Hu, recoverin, SOX1, titin, ZIC4, GAD65 and Tr antigens were incubated with patients’ serum according to the manufacturer’s instructions, modified and validated by our laboratory to adapt the test kit for veterinary diagnostics.

The strips were washed with a buffer provided in the kit and then incubated with the secondary alkaline-phosphatase conjugated goat anti-Canine IgG (SouthernBiotech, Birmingham, AL, USA) and goat anti-Cat (Bethyl Laboratories, Montgomery, TX, USA) antibodies. The onconeural antibodies in the serum bound to the related antigens were then visualized by NBT/BCIP substrate solution (nitroblue tetrazolium chloride/5-bromo-4chloro-3 indolylphosphate, Euroimmun). The intensity of binding of 11 ONHR antibodies was evaluated using EUROLineScan software (Euroimmun). An ONHR antibody band intensity value between 0 and 7 was considered negative or Class 0, between 8 and 14 was considered borderline or Class (+), between 15–35 and 36–70 as positive or Classes +, ++, and above 70 as strongly positive or Class +++. Strips with no added serum samples were used as negative controls.

 Indirect Immunofluorescence Assay

The Neurology Mosaic 8 testing kit (Euroimmun, FA 1111–1005-8) is an indirect immunofluorescence assay used to confirm the presence of autoantibodies against eight targets associated with cancers and neurological diseases. This test detects antibodies against Hu, Yo, CV2, Ri, Tr, ZIC4, GAD65, and amphiphysin. 

Serum samples were applied to the slides that were filled with BIOCHIPs – cerebellum and pancreatic sections collected from a monkey, according to the manufacturer’s instructions, and were modified and validated by our laboratory to adapt the test kit for veterinary diagnostics. Sera from a dog and a cat previously diagnosed with cancer were used as positive controls. A serum sample from a healthy dog or cat was included in each evaluation as the negative control. After incubation with diluted serum samples (1:10 to 1:100) for 30 min at room temperature, BIOCHIP slides were washed with phosphate-buffered saline/Tween (PBST) for 5 min and developed with secondary fluorescent-labeled antibodies (for dog samples: fluorescein isothiocyanate (FITC)-conjugated goat anti-Dog IgG, Euroimmun; for cat samples: FITC-conjugated goat anti-Cat IgG from Jackson ImmunoResearch Laboratories, West Grove, PA, USA). The BIOCHIP slides were then incubated for 30 min at room temperature and washed with PBST for at least 5 min. Immunofluorescent images were acquired with the EUROStar III Plus fluorescent microscope at ×20 and ×40. Each power field was captured in four quadrants using the same imaging technique. Serum samples from dogs and cats with positive results were retested with positive and negative controls to ensure the repeatability of the results.

Statistical Analysis

Sensitivity and specificity were determined as the fractions of true-positive results in the cancer-diagnosed/detected group and true-negative results in the control group, respectively, and calculated for results where borderline results were interpreted as negative. Confidence intervals (CIs) were determined to be 95% for all sensitivity and specificity calculations. Microsoft Excel (Microsoft Corporation, Redmond, WA, USA) and GraphPad Prism 10 (GraphPad, San Diego, CA, USA) online tools were used for statistical analyses.

https://www.tandfonline.com/doi/full/10.2147/VMRR.S537744#d1e278

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AVMA |News – FDA issues first-ever emergency use authorization for drug to combat screwworm in dogs

Meanwhile, new USDA playbook lists tools and resources for screwworm response

Published on November 12, 2025

Underscoring the gravity of the New World screwworm (NWS) threat looming just across the U.S.-Mexico border, on October 24 the Food and Drug Administration (FDA) published the first emergency use authorization (EUA) for the antiparasitic drug Credelio (lotilaner).

The is the first time the agency has invoked this emergency authority for an animal drug. In this case, it is for treatment of infestations of NWS in dogs and puppies. While most dogs in the U.S. are at low risk of contracting NWS due to their geographic location, dogs near the U.S.-Mexico border and dogs that travel to countries with active NWS cases are more likely to be exposed.

 “When it comes to emerging animal health threats, we need to be proactive, not reactive,” FDA Commissioner Marty Makary, MD, said in a press release.

The Food and Drug Administration (FDA) has taken the unprecedented step of issuing an emergency use authorization for a canine flea and tick medication for treatment of New World screwworm (NWS) infestations in dogs and puppies. 

Infestation

Screwworm flies target warm blooded animals, including livestock, dogs and other pets, wildlife, and humans, laying eggs in an open wound or orifice. Once the eggs hatch, NWS larvae spend the next several days consuming the host’s tissue, before reaching maturation and beginning the cycle again. NWS can cause serious damage to a host, which may die from secondary infection if not treated.

Detections of NWS have been on the rise in Central America and Mexico in recent months. In September, a screwworm case was identified in Sabinas Hidalgo, a Mexican city less than 70 miles from the Texas border, making it the northernmost detection during the current outbreak. A second detection, believed to be an isolated case and not related to the first, was detected in October in Montemorelos, about 100 miles further south in the same state.

U.S. and Mexican officials have heightened surveillance in the border region and the U.S. has closed its southern ports to imports of live cattle, bison, and horses from Mexico since July to prevent the parasite’s spread into the U.S., where it has essentially been eradicated since the 1960s.

https://www.avma.org/news/fda-issues-first-ever-emergency-use-authorization-drug-combat-screwworm-dogs?utm_source=delivra&utm_medium=email&utm_campaign=todays-headlines-news

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AVMA NEWS I Winter holiday pet safety

November and December abounds with holiday celebrations, and nothing can spoil good cheer like an emergency trip to the veterinary clinic. These tips can help keep your winter holiday season from becoming not-so-happy—for your pet and for you.

Plan in advance

Make sure you know how to get to your 24/7 emergency veterinary clinic before there’s an emergency. Talk with your veterinarian in advance to find out where you would need to take your pet, and plan your travel route so you’re not trying to find your way when stressed. Always keep these numbers posted in an easy-to-find location in case of emergencies:

• Your veterinarian’s clinic phone number

• 24/7 emergency veterinary clinic (if different)

• ASPCA Poison Control Center: 888-426-4435

• Pet Poison Helpline: 855-764-7661

Food 

Keep people food away from pets, and instruct everyone else to do the same. If you want to share holiday treats with your pets, make or buy treats formulated just for them. The following people foods are especially dangerous for pets:

• Chocolate is an essential part of holidays for many people, but it is toxic to dogs and cats. It’s safest to consider all chocolate off limits for pets, even though the harm it can cause varies based on the type of chocolate, the size of your pet, and the amount eaten.

• Other sweets and baked goods also should be kept out of reach. Not only are they often too rich for pets; they may contain the artificial sweetener xylitol, which has been linked to liver failure and death in dogs.

• Table scraps – including gravy, sauces, dressing, and meat or poultry fat or skin – should be kept away from pets. During the holidays, when our own diets tend toward extra-rich foods, table scraps can be especially hard for pets to digest and can cause pancreatitis. Bones can cause choking or intestinal blockage. Plus, many foods that are healthy for people are poisonous to pets, including onions, raisins, and grapes.

• Unbaked yeast dough can cause problems for pets, including painful gas and potentially dangerous bloating.

Quick action can save lives. Signs that your pet may have eaten something they shouldn’t include sudden behavior changes, depression, pain, loss of appetite, vomiting, or diarrhea. If your pet has any of these signs, call your veterinarian or nearest veterinary emergency clinic immediately. You may also want to call the ASPCA Poison Control Center (888-426-4435) or the Pet Poison Helpline (855-764-7661); note that a fee may apply.

Decorating

Holiday plants, lights, candles, and other decorations can make the holidays festive, but they also pose risky temptations for our pets.

• Ornaments can cause hazards for pets. Breakable ornaments can cause injuries, and swallowed ornaments can cause intestinal blockage or illness. Keep any ornaments, including those made from salt-based dough or other food-based materials, out of reach of pets.

• Tinsel, ribbons, wreaths, and other decorative materials also can be tempting for pets to play with and eat. These items whether swallowed in whole or in part can cause choking or intestinal blockage.

• Christmas trees can tip over if pets climb on them or try to play with the lights and ornaments. Consider tying your tree to the ceiling or a doorframe using fishing line to secure it.

• Water additives for Christmas trees can be hazardous to your pets if swallowed. Avoid adding anything to the water for your tree if you have pets in the house.

• Electric lights can cause burns when a curious pet chews the electrical cords.

• Candles and oil lamps are attractive to pets as well as people. Never leave a pet alone in an area with a lit candle or lamp; it could result in a fire.

• Flowers and festive plants can result in an emergency veterinary visit if your pet gets hold of them. Poinsettias, amaryllis, mistletoe, balsam, pine, cedar, and holly are among the common holiday plants that can be dangerous and even poisonous to pets who eat them. The ASPCA offers lists of plants that are toxic to dogs and cats.

• Potpourris should be kept out of reach of inquisitive pets. Liquid potpourris pose risks because they contain essential oils and other ingredients that can severely damage your pet’s mouth, eyes and skin. Non-liquid potpourris containing flowers, leaves, bark, herbs, and/or spices could cause problems if eaten.

Hosting parties and visitors

Visitors can upset pets, as can the noise and excitement of holiday parties and any celebratory fireworks. Even pets that aren’t normally shy may become nervous in the hubbub that can accompany a holiday gathering. The following tips will reduce emotional stress on your pet and protect your guests from possible injury.

• All pets should have access to a comfortable, quiet place indoors if they want to retreat. Make sure your pet has a room or crate somewhere away from the commotion, where your guests won’t follow, that your pet can go to anytime they want to get away.

• Inform your guests ahead of time that you have pets or if other guests may be bringing pets to your house. Guests with allergies or weakened immune systems (due to pregnancy, disease, or medications/ treatments that suppress the immune system) need to be aware of the pets (especially exotic pets) in your home so they can take any needed precautions to protect themselves.

• Guests with pets? If guests ask to bring their own pets and you don’t know how the pets will get along, you can either politely decline their request or plan to spend some time helping the pets to get to know each other, supervising their interactions, monitoring for signs of a problem, and taking action to avoid injuries to pets or people.

• Pets that are nervous around visitors should be put it in another room or a crate with a favorite toy. If your pet is particularly upset by houseguests, talk to your veterinarian about possible solutions to this common problem.

• Exotic pets make some people uncomfortable and may themselves be more easily stressed by gatherings. Keep exotic pets safely away from the holiday hubbub.

• Watch the exits. Even if your pets are comfortable around guests, make sure you watch them closely, especially when people are entering or leaving your home. While you’re welcoming hungry guests and collecting coats, a four-legged family member may make a break for it out the door and become lost.

• Identification tags and microchips reunite families. Make sure your pet has proper identification with your current contact information – particularly a microchip with registered up-to-date, information. That way, if your pet does sneak out, they’re more likely to be returned to you. If your pet isn’t already microchipped, talk to your veterinarian about the benefits of this simple procedure.

• Clear the food from your table, counters and serving areas when you are done using them and make sure the trash gets put where your pet can’t reach it. A carcass or large quantity of meat sitting out on the carving table, or left in a trash container that is easily opened, could endanger your pet if eaten. Dispose of carcasses and bones – and anything used to wrap or tie the meat, such as strings, bags and packaging – in a covered, tightly secured trash bag placed in a closed trash container outdoors (or behind a closed, locked door).

• Trash also should be cleared away where pets can’t reach it – especially sparkly ribbon and other packaging or decorative items that could be tempting for your pet to play with or eat.

When you leave the house

• Unplug decorations while you’re not around. Cats, dogs and other pets are often tempted to chew electrical cords.

• Take out the trash to make sure your pets can’t get to it, especially if it contains any food or food scraps.

Holiday travel

Whether you take your pets with you or leave them behind, take these precautions to safeguard them whenever you’re traveling. Learn more about traveling with pets.

• Interstate and international travel regulations require any pet you bring with you to have a health certificate from your veterinarian—even if you are traveling by car. Learn the requirements for any states or countries you will visit or pass through, and schedule an appointment with your veterinarian to get the needed certificate within the timeframes required by those destinations. (Even Santa’s reindeer need to get health certificates for their annual flight around the world!)

• Pets in vehicles should always be safely restrained and should never be left alone in the car in any weather. Proper restraint means using a secure harness or a carrier, placed in a location clear of airbags. Never transport your pet in the bed of a truck.

• If you’re traveling by air and considering bringing your pet with you, talk with your veterinarian first. Certain pets, such as short-nosed dogs and cats, may have difficulty with air travel. Your veterinarian is the best person to advise you regarding your own pet’s ability to travel.

• Pack for your pet as well as yourself if you’re going to travel together. In addition to your pet’s food and medications, this includes bringing copies of their medical records, information to help identify your pet if they become lost, first aid supplies, and other items. Refer to our Traveling with Your Pet FAQ for a more complete list.

• Boarding your dog while you travel? Talk with your veterinarian to find out whether and how to protect your pet from canine flu and other contagious diseases, and to make sure your pet is up-to-date on vaccines.

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AVMA – Online Publication Date: October 24, 2025

Improving noninvasive diagnosis of cutaneous and gastrointestinal forms of Pythium insidiosum infections in dogs: complementary roles of serum-based ELISA and polymerase chain reaction

Subarna Barua, PhD, Asfiha Tarannum, MS, Joseph Newton, DVM, Leonel Mendoza, PhD, Kelly Chenoweth, BS, Priscilla Barger, PhD, and Chengming Wang, DVM, PhD

Abstract

Objective

To evaluate the diagnostic performance of ELISA and PCR for detecting pathogenic oomycete infections and to explore associations with clinical presentation and treatment status.

Methods

Canine sera (n = 796) submitted to Pythium Serology Diagnostic Laboratory (from 2023 through 2025) were analyzed by ELISA to detect anti-Pythium antibodies and a PCR targeting Pythium insidiosum, Lagenidium spp, and Paralagenidium spp. Clinical records were reviewed for a subset of submissions. Analyses included χ2 tests, a linear mixed-effects model, and Cohen κ for ELISA-PCR agreement.

Results

Across all 697 samples tested by both methods, 69 (9.9%) were positive and 495 (71.0%) were negative by both assays, yielding an overall concordance of 81%. Polymerase chain reaction identified 5 cases, including cutaneous infections and Lagenidium infections tested to be negative by ELISA. Among confirmed positive submissions, ELISA detected anti-Pythium antibodies in 99.4% (182 of 183), whereas PCR detected Pythium DNA in 45.6% (72 of 158).

Conclusions

While ELISA is well suited for first-line screening due to its high sensitivity, PCR provides critical specificity and broader detection, especially in challenging cutaneous cases and when alternative pathogenic oomycetes are suspected. Enzyme-linked immunosorbent assay was highly effective for initial diagnosis and monitoring treatment response, and PCR was most useful for identifying active infections or relapses.

Clinical Relevance

The combined use of ELISA and PCR enhances diagnostic accuracy, improves detection of misdiagnosed Lagenidium infections, and guides clinical decision-making and epidemiological surveillance of this emerging and serious disease.

Keywords: gastrointestinal and cutaneous pythiosis; Pythium insidiosum; Lagenidium; ELISA; triplex PCR

Pythiosis is an emerging infectious disease of increasing concern in both veterinary and human medicine. It is caused by the oomycetes Pythium aphanidermatum, Pythium insidiosum, and Pythium periculosum, fungal-like organisms commonly referred to as the “water mold.”1,2 The disease is most commonly reported in tropical and subtropical regions,3 and within the US, it is endemic to the Southeast and Gulf Coast, though cases are increasingly documented nationwide.4,5

The infective stage of pathogenic Pythium spp is through biflagellate zoospores, which exhibit strong tropism for animal hair and tissues, initiating infection by encysting on damaged skin or gastrointestinal (GI) mucosa or by small pieces of environmental hyphae.6 While many infected animals have a history of repeated exposure to standing freshwater, other risk factors remain poorly defined.7

Canine pythiosis is typically diagnosed in 2 distinct clinical forms: cutaneous and GI, with the GI form being more commonly reported.3 Concurrent presentation of both forms is rare.8 The infection can disseminate to the pancreas, mesenteric lymph nodes, and bile ducts, whereas cutaneous lesions typically affect the limbs, face, or tail.9 Pythiosis is more frequently diagnosed in young, apparently immunocompetent dogs.8,10

Diagnosis of pythiosis is often delayed due to its nonspecific clinical presentation and the need for specialized diagnostic methods, such as culture, serology, and molecular testing.3,11,12 In the absence of pathognomonic clinical or histological features, pythiosis may be misdiagnosed as cases of zygomycosis or lagenidiosis.3,8 Phylogenetic analyses based on cytochrome oxidase II and large subunit ribosomal RNA gene sequences indicate that Lagenidium and Pythium are closely related.13,14 Given the phylogenetic and clinical similarities of these organisms, specific molecular assays are essential to distinguish Pythium from Lagenidium to guide appropriate therapy.10,15

Traditional diagnosis of pythiosis via microbiological culture is labor intensive and slow and requires skilled personnel.3,12 Immunological methods, such as ELISA16,17 and immunodiffusion,18 offer faster results by detecting serum antibodies against P insidiosum, though they are not commercially available and do not distinguish between active and past infections. Furthermore, they may be unreliable for localized infections, such as ocular pythiosis.19

Polymerase chain reaction–based molecular diagnostics have shown promise for specific detection, but most existing assays target only P insidiosum and do not differentiate it from other Oomycota pathogens.19 This limitation may delay accurate identification and negatively impact timely management and contributes to under-recognition of the disease. To address these challenges, we recently developed a multiplex molecular assay to improve accuracy in identifying P insidiosum and distinguishing it from other oomycetes.15 Building on this advancement, this study integrates serological and molecular methods in a large-scale surveillance effort to evaluate their combined diagnostic utility.

In this study, ELISA and, for the first time, PCR were both performed to detect anti-Pythium antibodies and Pythium DNA in canine sera. By comparing these results with clinical presentations (cutaneous vs GI) and treatment outcomes, we aim to evaluate the diagnostic strengths and limitations of each method and provide practical recommendations for clinical use.

Methods

Canine serum samples

A total of 796 canine serum samples submitted to the Pythium Serology & Mucormycosis Serology Laboratory at Auburn University College of Veterinary Medicine from October 2023 through February 2025 were included in this study. These samples represented 573 unique dogs, of which 456 (79.6%) had a single submission, and 117 (20.4%) had multiple submissions. Among dogs with serial submissions, 108 of 117 (92%) had 2 to 4 samples submitted, whereas 9 of 117 (8%) had 5 or more during the study period.

Of the total samples, 183 were from dogs diagnosed with pythiosis by other diagnostic modalities (eg, culture, histopathology, or immunohistochemistry) performed at external laboratories. Samples were classified as GI, cutaneous, or unusual (eg, thoracic) based on the clinical history provided by the submitting veterinarian on the test request form. Only samples submitted with adequate clinical history provided to allow definitive presentation were included in the comparison of GI and cutaneous presentations.

Samples were submitted from a wide range of breeds but were dominated by larger sporting-/working-type breeds, such as Labrador Retriever (n = 107), German Shepherd Dog (63), large mixed breed (43), Golden Retriever (31), Standard Poodle/large Doodle breeds (27), German Shorthaired Pointer (23), pit bull–type dog (23), Great Pyrenees (16), and others, whereas submissions from smaller-sized breeds, such as French Bulldog (13), Dachshund (13), Chihuahua (4), Pug (3), Boston Terrier (4), Maltese (4), and Miniature Schnauzer (4), were less common.

ELISA to detect anti-Pythium antibody

The ELISA used for the detection of anti–P insidiosum serum antibodies in this study was described previously,20,21 with minor modifications. Briefly, high-binding microtiter plates were coated with an optimal concentration of P insidiosum–concentrated minimal media antigen. After overnight incubation at 4 °C, plates were washed with PBS + 0.05% Tween 20, blocked with 1% normal goat serum for 4 hours at room temperature, and stored at −20 °C until use.

Positive controls were sera from culture-confirmed P insidiosum–infected dogs, and negative controls were from healthy dogs with no cutaneous or GI signs. Patient and control sera were diluted 1:1,000, 1:2,000, and 1:4,000 in PBS + 0.05% Tween 20, applied in triplicate to wells, and incubated at room temperature. After washing, secondary antibody (ALP-conjugated goat anti-dog immunoglobulin G; KPL ReserveAP; SeraCare) was added. Plates were incubated for 1 hour, washed, and developed with p-nitrophenyl phosphate. Optical density (OD) was read at 405 nm using a Synergy HTX microplate reader (BioTek). Blank OD values were subtracted, and titers were calculated using median values as previously described.21

Triplex PCR for P insidiosum, Lagenidium giganteum forma caninum, and Paralagenidium karlingii

Total nucleic acids were extracted from 200 µL of canine serum using an automated magnetic bead–based system (Indical Biosciences), yielding 100 µL of eluent. The triplex quantitative PCR was run on a LightCycler 96 PCR system (Roche) as described previously.15 Polymerase chain reaction products were confirmed by bidirectional Sanger sequencing (ELIM Biopharmaceuticals).

Statistical analysis

Serum samples (n = 123) from 115 dogs with confirmed pythiosis were used to assess the effects of disease presentation and sample dilution on antibody titers. Samples included 83 from dogs with GI involvement and 40 from dogs with cutaneous disease. Each sample was tested in triplicate at 3 serial dilutions (1:1,000, 1:2,000, and 1:4,000) using an in-house ELISA. The mean percentage of positivity was calculated for each dilution and used in statistical analyses. A mixed factorial design was applied, with disease presentation (GI vs cutaneous) as a between-subjects factor and dilution as a within-subject repeated measure. A linear mixed-effects model with random intercepts for individual dogs was used to account for repeated measures and unequal variances. Fixed effects included disease, dilution, and their interaction. Model assumptions were assessed using residual plots and the Levene test. Post hoc pairwise comparisons were adjusted using the Tukey method.

Diagnostic agreement between ELISA and PCR was evaluated using overall concordance and the Cohen κ coefficient (95% CI) for 697 paired samples tested by both methods. Because residuals suggested nonconstant variance across dilutions, a Kruskal-Wallis test was also performed as a nonparametric sensitivity analysis to confirm differences across dilutions. Concordance was defined as both tests yielding the same result (positive or negative). Kappa values were interpreted using standard benchmarks: < 0.20, slight; 0.21 to 0.40, fair; 0.41 to 0.60, moderate; 0.61 to 0.80, substantial; and > 0.80, almost perfect. Chi-square tests were used to compare (1) the prevalence of GI versus cutaneous pythiosis and (2) the proportion of positive results detected by ELISA versus PCR across all samples.

To assess whether certain breed groups were more likely to test positive for Pythium infection, dogs were classified into 2 groups based on primary breed as defined by the American Kennel Club. Sporting/working dogs included breeds traditionally used for hunting, herding, guarding, or similar outdoor activities (eg, Labrador Retrievers, German Shepherds, Goldendoodles, Great Pyrenees, Border Collies). Mixed-breed dogs were initially included with the sporting/working group based on typical medium-to-large body size and outdoor activity, but analyses were also repeated with mixed breeds excluded to assess the robustness of the findings.

Mixed-breed dogs without a clear primary breed were also assigned to this group. Smaller-sized dogs included primarily small indoor or lap breeds (eg, French Bulldogs, Dachshunds, Chihuahuas, Pugs, Yorkshire Terriers). Dogs whose primary breed did not clearly fit either category (eg, Greyhounds, English Bulldogs, Cocker Spaniels) were excluded to maintain consistent classification.

For each dog’s initial diagnostic submission, ELISA results were coded as strict positive (positive only based on ELISA/PCR) or inclusive positive (positive or suspect based on ELISA). For dogs that had multiple submissions, we only used the first (initial) sample to calculate sensitivity, so no single dog was counted more than once. Two-by-two contingency tables were used to compare positivity rates between these 2 groups. The Fisher exact test was applied due to the smaller sample size in the smaller-sized group, with χ2 test results also reported. Odds ratios and risk ratios with 95% CIs were calculated, applying the Haldane-Anscombe correction when needed.

All statistical analyses were performed using Python (version 3.11; scipy and statsmodels packages; Python Software Foundation), R (version 4.4.0; R Foundation for Statistical Computing), and Prism (version 10.4.2; GraphPad Software Inc). Statistical significance was set at P < .05.

Results

Concordance rate of 80% between ELISA and PCR

A total of 796 serum samples from 576 dogs were included. All samples were tested for anti-Pythium antibodies by ELISA, and 697 were also tested for Pythium DNA by PCR.

 Across the 697 samples tested by both assays, 69 of 697 (9.9%) were positive and 495 of 697 (71.0%) negative by both tests. Discordant results occurred in 133 of 697 (19.1%), including 5 samples (0.7%) PCR positive but ELISA negative or suspect and 128 of 697 (18.6%) ELISA positive or suspect but PCR negative (Figure 1; Table 1; Supplementary Figure S1; Supplementary Table S1).

Positivity rates of ELISA and PCR in dogs with gastrointestinal (GI) and cutaneous pythiosis based on initial and follow-up sample submissions. Dark-blue bars represent initial diagnostic positives, and light-blue bars represent follow-up positives. Striped regions indicate suspect ELISA results from initial submissions; PCR results were binary (positive or negative). Initial samples reflect diagnostic sensitivity, whereas follow-up samples illustrate test performance during treatment monitoring.

Citation: American Journal of Veterinary Research 2025; 10.2460/ajvr.25.07.0236

Table 1

Diagnostic results and inferred infectious status for pythiosis based on combined ELISA (antibody) and PCR results from 697 canine serum samples.

PCR Antibody No. of submissions Infectious status

Positive Positive 69 Actively infected

Positive Negative 2 Actively infected

Positive Suspect 3 Actively infected

Negative Positive 86 Infected (active or waning)

Negative Suspect 42 Potentially infected

Negative Negative 495 Likely uninfected

Results reflect the interpretation of both assays to classify samples as positive, negative, or suspect for Pythium infection.

The overall concordance rate between ELISA and PCR was 80.9% (564 of 697). The Cohen κ coefficient was 0.44 (95% CI, 0.37 to 0.50), indicating moderate agreement between the 2 assays. This reflects the complementary nature of these tests: ELISA identified nearly all confirmed cases, whereas PCR was more specific for detecting active infections with circulating Pythium DNA.

Of the total submissions, 183 samples were from dogs with confirmed or suspected pythiosis based on external diagnostics. Enzyme-linked immunosorbent assay detected 177 of 183 positives (96.7%), 5 of 183 suspects (2.7%), and 1 of 183 negatives (0.5%). Polymerase chain reaction was performed on 158 of these, yielding 72 of 158 positives (45.5%), including 3 of 4 ELISA-suspect samples. Among these cases, 127 of 183 (69%) were GI, 49 of 183 (27%) cutaneous, and 7 of 183 (4%) unusual or unknown presentations (Supplementary Figure S1; Supplementary Table S1). Across all samples, ELISA showed an overall sensitivity of 96.1%, increasing to 99.4% when suspect results were grouped with positives. Polymerase chain reaction sensitivity was lower at 48.8%, driven by reduced detection in GI cases.

Based on the presentation from 115 dogs with confirmed pythiosis (No. of sera, 123), ELISA sensitivity was found to be 85.0% for cutaneous cases (97.5% including suspect results) and 100% for GI cases, whereas PCR sensitivity was 61.7% for cutaneous and 44.2% for GI cases.

Diagnosis of cutaneous and GI pythiosis by ELISA and PCR

Based on available clinical history, GI pythiosis was significantly more common than cutaneous pythiosis, with 115 individual dogs presenting with GI involvement and 40 dogs presenting with cutaneous lesions (χ2 (1, n = 155) = 70.66; P < .0001). In addition, 1 case had concomitantly cutaneous and GI pythiosis, and 2 cases were thoracic.

Among initial diagnostic submissions from dogs with confirmed cutaneous pythiosis, ELISA (n = 40) identified 34 of 40 positive cases (87.5%) and 5 of 40 suspect cases (12.5%), whereas PCR (34) detected P insidiosum DNA in 21 of 34 cases (61.7%), including 3 that were classified as suspect by ELISA. When suspect ELISA results were excluded from analysis, ELISA demonstrated a significantly higher detection rate than PCR (χ2 (1, n = 34) = 11.25; P = .0008), indicating greater diagnostic sensitivity of ELISA at the time of initial evaluation. When suspect results were grouped with positives, the difference became even more pronounced (χ2 (1, n = 34) = 13.06; P = .0003), reflecting the importance of consistent interpretation of borderline results. Notably, PCR identified a substantial proportion of cutaneous cases and provided molecular confirmation in several suspect ELISA cases. These findings underscore the complementary roles of ELISA and PCR in cutaneous pythiosis diagnosis and highlight how classification of borderline serologic results can meaningfully affect diagnostic performance metrics.

For initial submissions from dogs with confirmed GI pythiosis (n = 115), ELISA identified all cases (100%), whereas PCR (95) detected P insidiosum DNA in 42 cases (44.2%; Figure 1; Table 2). This difference in detection rates was highly significant (χ2 (1, n = 95) = 82.89; P < .0001), indicating a higher sensitivity of ELISA in detecting positive GI cases. Both thoracic cases—an uncommon presentation of pythiosis—were positive by ELISA and PCR, highlighting the utility of these noninvasive assays for diagnosing atypical manifestations of infection.

Table 2

Comparison of ELISA and PCR detection rates in dogs with confirmed gastrointestinal and cutaneous pythiosis based on initial diagnostic submissions.

Presentation Test No. (%) positive No. (%) suspect No. (%) negative Total χ2 test P value

Gastrointestinal pythiosis ELISAa 115 (100) 0 (0) 0 (0) 115 < .001

PCR 42 (44.2) N/A 53 (55.7) 95

Cutaneous pythiosis ELISA 34 (85.0) 5 (12.5) 1 (2.5) 40 .0008

PCR 21 (61.7) N/A 15 (48.4) 34

N/A = Not applicable.

Cases were confirmed by culture, PCR, and/or histopathology performed at outside diagnostic laboratories, and results are based on the initial diagnostic submissions for each dog. Enzyme-linked immunosorbent assay demonstrated significantly higher detection rates than PCR in both gastrointestinal and cutaneous pythiosis cases. However, PCR confirmed Pythium DNA in 3 cutaneous samples that were classified as suspect by ELISA, highlighting its value as a complementary tool in cases with borderline serologic results.

Among follow-up samples submitted for antibody monitoring following an initial diagnosis of GI pythiosis (n = 123), ELISA identified 18 positive, 32 suspect, and 73 negative results. Polymerase chain reaction detected Pythium DNA in 4 of these samples. In recheck samples from dogs with cutaneous pythiosis (n = 32), ELISA yielded 8 positive, 9 suspect, and 15 negative results, whereas PCR detected DNA in 3 samples, including 1 that was classified as suspect by ELISA. These findings reflect a decline in both antibody levels and circulating pathogen DNA following treatment, which can reduce the sensitivity of both assays during follow-up testing.

Interestingly, the mean copy numbers of Pythium DNA detected by PCR were not significantly different between cutaneous and GI cases (cutaneous, 5,317 ± SD 5,068/mL serum; GI, 5,338 ± SD 5,095/mL serum). However, ELISA antibody titers were significantly higher in GI pythiosis than in cutaneous pythiosis at all dilutions (P < .0001; Figure 2).

Enzyme-linked immunosorbent assay positivity at serum dilutions in dogs with GI and cutaneous pythiosis. Each box represents the IQR, with the median indicated by the horizontal line. Whiskers extend to the minimum and maximum values within 1.5 times the IQR; dots indicate outliers. Dogs with GI pythiosis exhibited significantly higher antibody levels than those with cutaneous form (P < .0001). A linear mixed-effects model revealed significant effects of both disease presentation (P < .0001) and dilution (P < .0001) on ELISA titers, with no significant interaction between these factors (P < .1129). Titers also varied significantly across dilutions, confirmed by a Kruskal-Wallis test (H = 7.90; P < .0192) due to nonconstant variance (Spearman Rs = –0.6555; P < .0001).

Citation: American Journal of Veterinary Research 2025; 10.2460/ajvr.25.07.0236

The linear mixed-effects model revealed significant main effects of both disease presentation (P < .0001) and serum dilution (P < .0001) on ELISA antibody levels, with no significant interaction between these factors (P = .1129). Antibody levels in GI cases were consistently higher than in cutaneous cases across all 3 dilutions in initial sample submissions (Figure 2). Titers also varied significantly across dilutions as confirmed by a Kruskal-Wallis test (H = 7.90; P = .0192).

Antibody levels typically declined following successful treatment (Figure 3), with titers falling to ≤ 20% positivity at all 3 dilutions as infections resolved. Conversely, when surgical resection was incomplete or medical management failed, P insidiosum could persist subclinically, resulting in rising ELISA titers, which often preceded the return of clinical signs. In some cutaneous cases, particularly those treated with limb amputation or complete excision, antibody titers dropped rapidly and remained low, reaching normal levels at all dilutions by 6 months after surgery. In contrast, cases where resection was not feasible or incomplete showed an initial decline in titers with treatment, followed by either persistently elevated levels (often classified as suspect) or a secondary spike, indicative of ongoing infection. Polymerase chain reaction showed the absence of Pythium DNA decline after treatment.

Longitudinal serologic response in dogs diagnosed with pythiosis. Each panel shows serial ELISA results for an individual dog, with percentage of positive values over time by 3 dilutions. Month 0 marks the data from the initial submission, and the dotted lines indicate the 40% positivity cutoff. Most dogs showed declining titers after diagnosis, though some had persistent or rebounding antibody levels, suggesting ongoing antigen exposure or incomplete clearance. The gold box in A at month 0 represents a positive PCR on the initial sample, whereas a PCR was not performed on the initial samples for any of the other animals. The cases in A and B were cutaneous, whereas the remaining 4 cases were in GI presentation.

Citation: American Journal of Veterinary Research 2025; 10.2460/ajvr.25.07.0236

Multiple submissions

Fifty-three cases had more than 1 sample submission. For each, serologic and molecular results were evaluated in the context of clinical history.

ELISA- and PCR-negative cases

Twenty-two cases, each with up to 5 submissions, were consistently negative by both ELISA and PCR. These were typically follow-up samples from previously diagnosed and treated cases submitted over months to years to monitor treatment response.

Case 1: A cutaneous pythiosis case initially diagnosed by culture and ELISA, with multiple negative follow-up submissions during treatment.

Case 2: Diagnosed with GI pythiosis by ELISA in May 2023 and enrolled in a clinical trial. Samples submitted ≥ 6 months after treatment began were negative by both tests, and the dog was clinically normal.

ELISA- and PCR-positive cases

Four cases tested positive by both ELISA and PCR, with intervals of up to 3 months between submissions.

Case 3: Cutaneous pythiosis diagnosed in December 2023; initial positive ELISA and subsequent recurrence of lesions in February 2024 with PCR positivity.

Case 4: Diagnosed in August 2024; persistent cutaneous lesions and strong PCR positivity in October 2024 despite ELISA titers falling to the suspect range.

Case 5: Chronic GI pythiosis with incomplete surgical resection. Enzyme-linked immunosorbent assay remained positive across multiple submissions; PCR was initially and finally positive but negative at 1 intermediate time point.

ELISA-negative and PCR-positive cases

Case 6: Presented with GI signs and masses. Two samples (January 19 and February 7, 2025) were ELISA negative (≤ 7% at all dilutions), but the first was PCR positive and the second PCR negative.

ELISA-positive/suspect and PCR-negative cases

Twenty-one cases were ELISA positive or suspect but PCR negative. Many were follow-up submissions from treated animals, where circulating antibody levels may have persisted while DNA was no longer detectable.

Case 7: A cutaneous case with 8 submissions from November 2023 through October 2024. Enzyme-linked immunosorbent assay titers declined throughout the course of treatment, and all PCR results were negative.

Case 8: Gastrointestinal case with 3 submissions. Enzyme-linked immunosorbent assay was positive on the first and negative on the remaining 2, and all PCR tests were negative.

Breed might be a risk factor for canine pythiosis

When considering cases that were PCR positive or ELISA positive/suspect as pythiosis, active outdoor breeds appeared more likely to be infected than smaller, traditionally smaller-sized dogs (Table 3). Sporting and working breeds (eg, Great Pyrenees [9 of 16 (56%)], Goldendoodle [8 of 18 (44%)], German Shorthaired Pointer [10 of 23 (43%)]) had higher positivity rates than predominantly smaller-sized breeds (eg, French Bulldog [1 of 13 (8%)], Dachshund [0 of 13 (0%)], other smaller-sized breeds [1 of 24 (4%)]; Supplementary Table S2). Among the 599 dogs classified as either sporting or smaller-sized breeds, 136 were strict positives (ELISA/PCR positive), and 160 were inclusive positives (ELISA positive or suspect). Sporting/working dogs had a significantly higher positivity rate than smaller-sized dogs. Using the Strict analysis, sporting/working dogs were 3.5 times more likely to test positive (Fisher exact P = .00088). When suspect cases were included, the association strengthened, with sporting/working dogs 4.4 times more likely to test positive (Fisher exact P = 2.31 X 10−5). To reassess the potential subjectivity of assigning mixed-breed dogs to the sporting/working group, we repeated the analysis with mixed breeds excluded. The results were unchanged, with sporting/working dogs still significantly more likely to test positive than smaller, traditionally indoor-type dogs under both strict (Fisher exact P = .0129) and inclusive (Fisher exact P = .0010) definitions. These findings indicate that sporting/working dogs are at a significantly greater risk of pythiosis, likely due to increased environmental exposure to aquatic habitats where P insidiosum thrive.

Table 3

Comparison of Pythium positivity rates between sporting/working and smaller-sized dogs.

Group Negative (strict) Positive (strict) Negative (inclusive) Positive (inclusive)

Smaller sizeda 74 7 74 7

Sporting/workingb 389 129 365 153

Total 463 136 439 160

Diagnostic submissions were classified as sporting/working (n = 518) or smaller sized (81). Strict positives include only positive results by ELISA and/or PCR, whereas inclusive positives include both positive and suspect results by ELISA. Sporting/working dogs were significantly more likely to test positive for pythiosis than smaller-sized dogs. In the strict analysis, the Fisher exact test yielded P = .00088; OR, 3.51 (95% CI, 1.57 to 7.80); and risk ratio, 2.88 (95% CI, 1.40 to 5.94). In the inclusive analysis, P = 2.31 X 10−5; OR, 4.43 (95% CI, 2.00 to 9.84); and risk ratio, 3.42 (95% CI, 1.66 to 7.02). These results indicate that sporting/working dogs were about 3.5 to 4.4 times more likely to test positive for pythiosis than smaller-sized dogs.

Smaller-sized dogs include French Bulldogs, Chihuahuas, and Pugs.

Sporting/working dogs include Labrador Retrievers, Border Collies, and mixed breeds. Breeds not clearly fitting either group were excluded.

Lagenidium-positive cases by PCR

The triplex PCR identified 6 Lagenidium-positive cases; no cases were positive for Paralagenidium. All 6 cases were reported as cutaneous presentations of pythiosis and were negative by ELISA and PCR for Pythium. In 4 of 6 cases, histopathology described hyphae suggestive of Pythium, and several were chronic or recurrent. One had previously been misdiagnosed as P insidiosum based solely on histopathology.

Case 9: A cutaneous case with a history of disseminated multifocal necrotic lesions requiring multiple aggressive surgical excisions and medical management with recurrence at the surgical site. Hyphae were noted on histopathology. Enzyme-linked immunosorbent assay negative for P insidiosum and PCR positive for Lagenidium.

Case 10: A cutaneous case was evaluated with 2 sample submissions taken 4 months apart. The initial diagnosis was pythiosis based on histopathologic evidence of hyphae despite an inconclusive pan-fungal PCR and a negative ELISA. Upon reevaluation, the second sample tested positive for Lagenidium via serum PCR, whereas the Pythium ELISA remained negative.

Discussion

This study presents the largest comparative evaluation of anti-Pythium antibody ELISA and serum-based PCR for diagnosing canine pythiosis. By integrating clinical history with test results, we provide new insights into the strengths and limitations of both diagnostic tools.

Our results support ELISA as a highly sensitive tool for both diagnosis and monitoring of pythiosis, particularly in cases with GI involvement. The ELISA used to detect anti–P insidiosum serum antibodies in this study was based on previously described protocols,16,20 with minor modifications. Specifically, instead of a single dilution as used in the original protocols, serum samples in this study were tested at dilutions of 1:1,000, 1:2,000, and 1:4,000. Each sample was then categorized as positive, suspect, or negative based on a 40% cutoff of the OD value. This 3-tiered ELISA interpretation system more accurately reflected the clinical condition than the original single-dilution approach.

Diagnostic sensitivity was found to be highest in this study when evaluating initial submissions, with ELISA identifying 182 of 183 (99.4%) confirmed positive cases as positive or suspect and PCR detecting 72 of 158 (45.6%). In contrast, sensitivity declined in follow-up samples from dogs undergoing treatment. Among follow-up samples submitted for antibody monitoring after an initial GI pythiosis diagnosis (n = 123), ELISA identified 18 of 123 positive (14.6%), 32 of 123 suspect (26.0%), and 73 of 123 negative (59.3%) results, whereas PCR detected Pythium DNA in only 4 cases. For cutaneous follow-up samples (n = 32), ELISA yielded 8 of 32 positive (25%), 9 of 32 suspect (28.1%), and 15 of 32 negative (46.9%) results, whereas PCR detected DNA in 3 of 32 samples (9.4%). This decline in detection reflects the expected reduction in both circulating antibody and pathogen DNA levels following effective treatment.12

Enzyme-linked immunosorbent assay testing on multiple submissions from the same dogs demonstrated that anti-Pythium antibody titers decline predictably over time and may signal clinical improvement. However, persistently elevated or suspect ELISA results often indicated incomplete resolution or relapse even in animals that appeared clinically normal, particularly in the postoperative setting.22 Thus, ELISA serves as an early diagnostic tool in chronic or recurrent cases.12,16 Moreover, serial monitoring using both ELISA and PCR may help identify subclinical recurrence before clinical signs reappear.23 In one such case, PCR detected Pythium DNA in a sample with a suspect ELISA result, underscoring the value of molecular confirmation when antibody levels are low.

Although PCR detection rates were numerically higher for cutaneous pythiosis (61.7%) compared to GI cases (44.2%), this difference was not statistically significant. However, PCR may still offer critical diagnostic value in cutaneous presentations, where anti-Pythium antibody titers tend to be lower and serologic results may be more ambiguous.23 Given the overlap in clinical and histologic appearance between cutaneous pythiosis and other oomycotic infections—such as Lagenidium or Paralagenidium—PCR’s ability to directly detect and differentiate pathogen DNA in serum can enhance diagnostic accuracy.8,15,23 This is especially valuable when ELISA results are borderline or inconclusive. In such cases, integrating PCR as a confirmatory tool can help resolve diagnostic uncertainty and guide appropriate clinical management. These findings support the complementary use of ELISA and PCR not only for diagnosis but also for treatment monitoring and long-term disease surveillance in dogs with pythiosis.12,23

Serum-based PCR, used here for the first time in this context, offers direct evidence of active infection by detecting circulating P insidiosum DNA. Unlike traditional tissue-based PCR,24,25 this approach is less invasive and more practical for systemic infections. While PCR had lower overall positivity than ELISA, its specificity for active infection makes it a valuable complement, especially when ELISA results are ambiguous or delayed due to host immune response.26 Serum was used for PCR in this study, but EDTA plasma, especially the buffy coat and tissues, may yield more DNA and improve PCR sensitivity. Future research should evaluate optimal sample types for molecular diagnostics in pythiosis.

Notably, some animals tested PCR positive but ELISA negative, suggesting early or silent infections.19,27 Others were ELISA positive but PCR negative, likely due to antibody persistence following treatment or low pathogen load in localized infections. These findings underscore the importance of using both tests in tandem for comprehensive diagnosis and monitoring.

The multiplex PCR used in this study also distinguished Pythium from Lagenidium, 2 morphologically similar oomycetes with different treatments.15 Six cutaneous cases initially suspected of being Pythium but negative by ELISA were confirmed to be Lagenidium, highlighting the diagnostic value of molecular testing over histopathology alone as well as the specificity of the ELISA.

Environmental exposure appears to play a role in disease risk.3,28,29 Sporting/working dogs showed significantly higher pythiosis rates, supporting the association with swampy or aquatic habitats.30 Smaller-sized dogs had lower positivity, reinforcing the environmental nature of exposure.

In total, 69 samples were positive by both ELISA and PCR, and 3 suspect ELISA samples were positive by PCR, suggesting the possible presence of Pythium immune complexes in serum or plasma, similar to what is observed in heartworm disease.31,32 Studies using heat or chemical pretreatment of serum may enhance ELISA sensitivity and deserve further investigation.31

In summary, this study provides the most comprehensive comparison of anti-Pythium antibodies by ELISA and PCR detection of Pythium DNA in sera from canines with suspected and active pythiosis to date. Enzyme-linked immunosorbent assay remains the cornerstone for diagnosing and monitoring pythiosis, and serum PCR introduces a novel noninvasive tool to confirm active infection and differentiate between pathogenic oomycetes. Used together, they offer a comprehensive diagnostic strategy for managing this challenging disease. Future studies should focus on understanding antigenemia kinetics and validating this dual-testing approach across host species and regions.

Supplementary Materials

Supplementary materials are posted online at the journal website: avmajournals.avma.org.

Acknowledgments

None reported.

Disclosures

The authors have nothing to disclose. No AI-assisted technologies were used in the composition of this manuscript.

https://avmajournals.avma.org/view/journals/ajvr/aop/ajvr.25.07.0236/ajvr.25.07.0236.xml

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BMC Veterinary Research volume 21, Article number: 605 – Published: October 14, 2025

The impact of anxiety on canine heart function: a study using echocardiographic techniques

Delara Soghyani, Farnoosh Arfaee, Mohammad Molazem, Reihaneh Soflaei & Arman Abdous 

Abstract

Canine anxiety is increasingly recognized in veterinary practice, yet its cardiovascular effects remain poorly defined. This study evaluated 36 anxious dogs and 20 healthy controls using the validated Canine Behavioral Assessment and Research Questionnaire (C-BARQ) and standardized echocardiography. Significant associations were identified between anxiety subtypes and cardiac parameters: general anxiety correlated with increased fractional shortening (FS%; r = 0.663, p = 0.001), phonophobia with larger left ventricular internal dimension in diastole (LVIDd; r = 0.681, p < 0.001), and aggression with a higher left atrial-to-aortic root ratio (LA/Ao; r = 0.475, p = 0.008). Rhythm irregularities were suspected in nearly half of anxious dogs, though classification was limited without ECG confirmation. By contrast, correlations in controls were weak and non-significant.These results provide novel evidence that chronic behavioral anxiety is associated with measurable echocardiographic alterations in dogs, paralleling mechanisms described in human psychocardiology. Incorporating behavioral screening into routine veterinary practice may support early identification and monitoring of dogs at risk for anxiety-related cardiac changes. Larger longitudinal studies with matched controls, ECG verification, and size-indexed parameters are warranted to confirm causality and guide preventive care strategies.

Introduction

Anxiety in dogs is an increasingly recognized concern in veterinary medicine, affecting a significant portion of the canine population [1]. Conditions such as separation anxiety, noise phobia, and generalized fear can lead to behavioral disturbances and reduce quality of life. Emotional stress in animals has been associated with various physiological consequences, including gastrointestinal disorders and compromised immune function; however, its specific impact on cardiovascular health remains underinvestigated [2, 3].

In contrast, a large body of human research links anxiety to cardiovascular dysfunction. Chronic anxiety in people is associated with altered heart rate variability, heightened sympathetic tone, and structural changes such as diastolic dysfunction and atrial enlargement—often detectable through echocardiography. Although parallels between human and canine physiology suggest similar psychocardiological mechanisms may occur in dogs, most veterinary studies have focused on physical stressors like exercise or anesthesia rather than emotional triggers [4, 5]. Consequently, the influence of chronic behavioral anxiety on canine cardiac function, particularly as assessed by advanced non-invasive echocardiographic techniques, remains largely unexplored [3].

Canine heart disease itself can arise from congenital abnormalities, acquired degenerative conditions such as mitral valve disease, or myocardial disorders including cardiomyopathies [6, 7]. Clinical signs may include fatigue, coughing, exercise intolerance, and dyspnea. Echocardiography—using B-mode, M-mode, and Doppler modalities—has become a cornerstone of cardiac diagnostics in veterinary practice. It provides quantitative insight into chamber size, systolic function, wall motion, and blood flow dynamics [8]. Commonly evaluated parameters include left ventricular internal dimensions at systole and diastole (LVIDs and LVIDd), ejection fraction (EF%), fractional shortening (FS%), and the left atrial-to-aortic root ratio (LA/Ao) [9].

This study was designed to address the knowledge gap by comparing echocardiographic parameters in anxious dogs and clinically healthy, non-anxious controls. By integrating validated behavioral assessment tools with echocardiographic evaluation, we aimed to determine whether chronic emotional stress contributes to subclinical or early-stage cardiovascular changes. Identifying such links could support the incorporation of behavioral screening into cardiac risk assessment, potentially enabling earlier intervention and improved clinical outcomes.

Methods

Study design

This observational, cross-sectional study was conducted over a six-month period at the Islamic Azad University, Science and Research Branch. Its objective was to assess whether anxiety-related behaviors are associated with alterations in canine cardiac parameters measured through advanced echocardiographic techniques.Dogs were assigned to either an anxiety group or a control group based on behavioral assessment. The anxiety group included dogs with owner-reported signs such as excessive fear of loud noises, separation-related distress, or generalized nervousness. The control group consisted of clinically healthy, non-anxious dogs. Both groups underwent identical echocardiographic protocols, enabling direct comparison of cardiac function. An overview of the experimental workflow is provided in Supplementary Figure S1.

Ethical considerations

The study was conducted in accordance with institutional ethical standards and approved by the Ethics Committee of the Islamic Azad University, Science and Research Branch, Tehran. Prior to participation, owners of all dogs in both groups received detailed written and verbal information about the study’s objectives, procedures, and potential risks. Written informed consent was obtained, and participants were assured of their right to withdraw at any time without consequence.All echocardiographic procedures were performed by licensed veterinary professionals with specialized training in cardiology. Humane treatment guidelines for animal research were strictly followed, with gentle handling and procedures designed to minimize stress and ensure animal welfare.

Study population

A total of 74 dogs were screened at the hospital of the Islamic Azad University, Science and Research Branch (Tehran), and affiliated veterinary clinics. Eighteen were excluded—11 due to current or recent use of psychotropic medications and 7 due to comorbid medical conditions—leaving 56 dogs enrolled. Of these, 36 met the criteria for the anxiety group, while 20 clinically healthy, non-anxious dogs served as controls.The anxious group included dogs aged 1–12 years, representing a diverse mix of breeds and sizes to enhance generalizability. Inclusion criteria required owner-reported signs of anxiety—such as noise sensitivity, separation distress, or nervousness in unfamiliar situations—persisting for at least three months, confirmed through history or clinical documentation. Dogs with prior diagnoses of heart disease were excluded to isolate the effect of behavioral anxiety on cardiac function. Additional exclusion criteria included cardiovascular, neurological, or systemic conditions that might affect echocardiographic results, as well as treatment with medications for anxiety or behavioral disorders (e.g., trazodone, fluoxetine, gabapentin).The control group consisted of 20 dogs free of cardiac or behavioral disorders, with consistently low C-BARQ scores (mean global anxiety score: 0.64 ± 0.18). Their mean age was 4.9 ± 3.0 years (range 1.1–9.7), and body weights ranged from 4.4 to 15.0 kg. To minimize environmental and handling differences, control dogs were drawn from the same clinical population and underwent identical echocardiographic evaluation.

Behavioral assessment of anxiety

Behavioral anxiety was quantified using an adapted version of the Canine Behavioral Assessment and Research Questionnaire (C-BARQ), a standardized instrument widely applied in clinical behavioral research to characterize emotional reactivity in dogs. Six domains were evaluated: separation anxiety, noise sensitivity (phonophobia), fear, aggression, obsessive-compulsive behaviors, and generalized anxiety. Owners rated the frequency of each behavior on a 5-point Likert scale, where 0 indicated “never,” 1 “rarely,” 2 “sometimes,” 3 “often,” and 4 “always.” Observable signs such as excessive barking, destructiveness when left alone, trembling, hiding, or hypervigilance were used to guide accurate scoring.Following completion of the questionnaire, total anxiety scores were calculated as the unweighted arithmetic mean of responses across the six domains, providing a standardized measure of each dog’s overall anxiety level. Dogs were then stratified into three categories: scores below 1.5 were classified as low anxiety, scores between 1.5 and 2.5 as moderate anxiety, and scores above 2.5 as high anxiety. Control dogs consistently demonstrated low scores across all domains, confirming their non-anxious status.

Echocardiographic assessment

Echocardiographic examinations were performed by a board-certified veterinary cardiologist using a Philips EPIQ 7 ultrasound system equipped with high-resolution B-mode, M-mode, and Doppler functionalities. A sector-array phased transducer probe with a frequency range of 3.5–8 MHz was used for thoracic imaging, as it provides deep penetration with high temporal resolution. For very small dogs (< 3 kg), higher-frequency probes (>8 MHz) were employed to enhance spatial resolution and minimize measurement error, ensuring consistent image quality across the range of body sizes represented in the study.This imaging platform enabled detailed evaluation of cardiac structure and function, including real-time assessment of ventricular wall motion, valve morphology, and blood flow dynamics. Standard veterinary echocardiographic protocols were followed [10] Key measurements included left ventricular internal dimensions at end-systole (LVIDs) and end-diastole (LVIDd), interventricular septal thickness (IVS), fractional shortening (FS%), and ejection fraction (EF%). These indices are central to evaluating myocardial size, contractile performance, and systolic function. M-mode echocardiography was used for precise dimensional analysis of the left ventricle, B-mode imaging for overall morphology and detection of abnormalities such as wall motion irregularities or chamber dilation, and Doppler for intracardiac blood flow and identification of valvular regurgitation across the mitral, aortic, and tricuspid valves. Together, these methods provided comprehensive insight into both structural and hemodynamic aspects of cardiac performance.All echocardiographic data were recorded systematically and analyzed in relation to behavioral anxiety classifications. Both anxious and control dogs underwent identical assessment protocols during a single clinical visit, allowing for direct comparison of structural and functional parameters and evaluation of the potential influence of emotional stress on cardiac function.

Statistical analysis

Analyses were conducted using IBM SPSS Statistics v26. Descriptive statistics (means, standard deviations, and frequencies) were used to summarize demographic, behavioral, and echocardiographic data. Linear associations between anxiety scores, age, and cardiac parameters were assessed with Pearson’s correlation coefficients. To control for multiple comparisons, p-values were adjusted using the false discovery rate (FDR), and only associations that remained significant after correction were interpreted. Statistical significance was defined as two-tailed p < 0.05. Results are reported with correlation coefficients, 95% confidence intervals, effect sizes, and p-values, with selected associations illustrated graphically. A post-hoc power analysis (α = 0.05) showed that the sample size (36 anxious and 20 control dogs) provided > 80% power to detect between-group differences of medium effect size (Cohen’s d ≥ 0.65) and correlations of r ≥ 0.44 within the anxious cases.

Results

Demographic and sample characteristics

The anxious group consisted of 36 dogs ranging in age from 1 to 12 years, with the largest proportions being 1 year (19.4%) and 2 years (16.7%). Senior dogs, defined as those aged 7 years or older for small to medium breeds, represented 25% of the anxious cases. Breed diversity was notable: Shiba Inu (22.2%), Maltese (19.4%), Miniature Poodle (16.7%), and Jack Russell Terrier (13.9%) were the most common, while French Bulldog, Terrier, Shih Tzu, and Bichon Frise were also represented, creating a heterogeneous sample of small- to medium-sized companion breeds.

Body-weight distribution in the anxious group was skewed toward very small dogs, with 58.3% weighing less than 3 kg. Dogs in the 3–5 kg and 5–10 kg categories accounted for 19.4% and 13.9% of the group, respectively, while 8.3% weighed between 10 and 15 kg. This pattern likely reflects regional breed preferences and the higher prevalence of anxiety in toy and miniature breeds.

The control group (n = 20) consisted of clinically healthy dogs with a mean age of 4.9 ± 3.0 years (range 1.1–9.7). Their body weights ranged from 4.4 to 15.0 kg, and breed distribution is shown in Table 1. In contrast to the anxious group, which was predominantly composed of dogs under 3 kg, the control group displayed a more balanced distribution across weight categories. Age was further examined in relation to both behavioral anxiety scores and echocardiographic variables, with correlation patterns presented in Sect. 3 and summarized in Table 2.

Table 1 Demographic characteristics of anxious dogs (n = 36) and control dogs (n = 20)

Table 2 Echocardiographic measurements and distribution relative to reference ranges in anxious dogs (n = 36) and control dogs (n = 20)

Cardiovascular parameter results

As summarized in Table 2, echocardiographic assessments revealed several findings related to cardiac structure and function. In the anxious group, the mean left ventricular internal dimension at end-systole (LVIDs) was 24.49 ± 4.90 mm, the average ejection fraction (EF%) was 73.61 ± 13.95%, and fractional shortening (FS%) averaged 42.14 ± 10.96%. The left atrial-to-aortic root ratio (LA/Ao) had a mean of 1.47 ± 0.24 (range 1.0–2.0).

When compared with uniform reference ranges, several parameters fell outside the suggested limits. LVIDd was above range in 33.3% and below in 5.6% of anxious dogs. FS% exceeded the standard 25–45% range in 44.4%, while LA/Ao was greater than the conventional 1.3 cutoff in 80.6%. These proportions should be interpreted cautiously, as fixed reference values may not fully account for body size differences. In contrast, interventricular septal thickness in diastole (IVSd) was within the normal range in all anxious dogs. A detailed breakdown of deviations is provided in Table 2.The control group showed values largely within normal limits. Mean LVIDd was 36.50 ± 4.00 mm, FS% was 34.50 ± 5.00%, and EF% was 67.50 ± 7.00%, with only minor deviations observed (e.g., 15% of dogs with LVIDd above reference and 10% with EF% above reference). No significant structural or functional abnormalities were detected in this group.

Suspected rhythm irregularities were identified in 47% (17/36) of anxious dogs based on auscultation and echocardiographic observation. The most frequent pattern was a non-specific irregular rhythm (38.9%), followed by findings suggestive of conduction disturbances (22.2%). Less common abnormalities included single cases of tachycardia, bradycardia, and murmurs possibly consistent with mitral regurgitation. As ECG confirmation was not available, these should be regarded as provisional rather than definitive diagnoses. Categories were not mutually exclusive, since some dogs exhibited more than one finding. The distribution of abnormalities is illustrated in Fig. 1.

Fig. 1

Frequency of detected rhythm and auscultatory irregularities in anxious dogs (n = 36) compared with control dogs (n = 20). Values reflect findings based on auscultation and echocardiographic observation. Arrhythmia types remain non-specifically categorized due to absence of ECG; no abnormalities were observed in control dogs. Categories are not mutually exclusive; a dog could contribute to more than one finding, and percentages therefore do not sum to 100%

Correlation between anxiety and cardiovascular parameters

Statistical analysis revealed significant correlations between specific anxiety subtypes and key echocardiographic parameters in anxious dogs. General anxiety was positively associated with fractional shortening (FS%) (r = 0.663, p = 0.001, q = 0.004). Phonophobia showed a strong positive correlation with left ventricular internal dimension at end-diastole (LVIDd) (r = 0.681, p < 0.001, q = 0.004). Although 61.1% of anxious dogs had LVIDd values within the reference range, those with higher phonophobia scores tended toward larger or above-reference diastolic dimensions, which may partly reflect body size variation or measurement variability. Aggression was correlated with the left atrial-to-aortic root ratio (LA/Ao) (r = 0.475, p = 0.008, q = 0.016); however, because LA/Ao values exceeded 1.3 in most anxious dogs, this association should be regarded as exploratory (Table 3, Fig. 2).By contrast, none of these associations were significant in the control group (all p > 0.6, r < 0.2), indicating that the observed relationships between anxiety traits and cardiac parameters were specific to anxious dogs.

Table 3 Correlation Analyses Related to Anxiety and Cardiac Function. Pearson correlations between anxiety subtypes and echocardiographic parameters in anxious (n = 36) and control (n = 20) dogs

Fig. 2

Mean ± standard deviation (SD) of anxiety-related behavioral parameters in anxious dogs (n = 36) compared with control dogs (n = 20), based on C-BARQ questionnaire results. Control dogs consistently exhibited minimal scores across all domains, whereas anxious dogs showed markedly elevated scores, particularly in phonophobia, fear, and separation anxiety

Heart rate also showed significant associations with multiple cardiac indices in the anxious cases. It correlated strongly with left ventricular free wall thickness in systole (LVFWs) (r = 0.833, p < 0.001, q = 0.002), FS% (r = 0.663, p = 0.001, q = 0.006), and EF% (r = 0.644, p = 0.002, q = 0.008) (Table 4, Fig. 2). A positive correlation was also observed with LVIDd (r = 0.681, p < 0.001, q = 0.002), although this finding contrasts with physiological expectations, as tachycardia typically reduces diastolic filling. This pattern may therefore reflect confounding by body size, anxiety severity, or measurement variability. Taken together, these results suggest synchronized increases in contractility and myocardial wall thickness in dogs with higher heart rates. In the control group, heart rate correlations with echocardiographic indices were weak and non-significant (all p > 0.2).

Table 4 Correlation Analyses Related to Anxiety and Cardiac Function. Correlation coefficients between heart rate and echocardiographic parameters, and among cardiac metrics, in anxious (n = 36) and control (n = 20) dogs

Further analysis of inter-parameter relationships (Table 5) demonstrated several significant associations in anxious dogs. FS% correlated positively with interventricular septal thickness in systole (IVSs; r = 0.401, p = 0.048, q = 0.049) and negatively with LVIDs (r = − 0.476, p = 0.029, q = 0.041). EF% was also negatively correlated with LVIDs (r = − 0.452, p = 0.037, q = 0.046). LA/Ao correlated significantly with IVSs (r = 0.389, p = 0.041, q = 0.049), LVIDs (r = 0.427, p = 0.042, q = 0.049), and FS% (r = 0.498, p = 0.025, q = 0.036). These findings indicate consistent internal relationships between functional and geometric cardiac parameters in anxious dogs, though interpretation is limited by the use of uniform reference ranges. In the control group, such interrelationships were again weak and non-significant (r < 0.2, p > 0.5).

Table 5 Correlation Analyses Related to Anxiety and Cardiac Function. Interrelationships between cardiac structural and functional indices in anxious (n = 36) and control (n = 20) dogs

Age also influenced several structural measures. Younger anxious dogs exhibited lower IVSs, with a positive but non-significant correlation between age and IVSs (r = 0.291, p = 0.084). By contrast, LVFWd and LVFWs were strongly correlated (r = 0.843, p < 0.001, q = 0.002), reflecting consistent myocardial wall thickening across age groups. These patterns were observed in both anxious and control dogs, although statistical significance was reached only in the anxious cases.

Anxiety profile distribution and summary

Behavioral anxiety scores in the anxious group (n = 36) demonstrated wide variability across domains. Fear-related behaviors were among the most prominent: 33.3% of dogs scored between 2 and 3, while 44.4% scored between 3 and 4, indicating moderate to high levels of fearfulness. Aggression scores, by contrast, were consistently low, with 41.7% of dogs scoring below 1 and 55.6% between 1 and 2; notably, none exceeded a score of 3.Phonophobia showed the greatest variability. About 27.8% of anxious dogs scored between 2 and 3, while 36.1% scored above 4, reflecting heightened sensitivity to loud or sudden noises. General anxiety occurred mainly at low to moderate levels, with 50.0% of dogs scoring between 1 and 2 and 47.2% between 2 and 3. Separation anxiety displayed a more balanced distribution: 41.7% scored between 2 and 3, 22.2% between 1 and 2, and 8.3% between 3 and 4. Obsessive-compulsive behaviors (OCD) were least common, with 63.9% of anxious dogs scoring below 1 and only 5.6% scoring 2 or higher.In contrast, the control group (n = 20) consistently showed minimal anxiety-related behaviors. Their mean C-BARQ scores ranged from 0.20 ± 0.18 for obsessive-compulsive behaviors to 0.64 ± 0.18 for general anxiety, confirming their role as a non-anxious comparator group (Table 6; Fig. 3).As illustrated in Fig. 3, phonophobia had the highest mean score among anxious dogs (2.74 ± 1.15), followed by fear (2.24 ± 0.89) and separation anxiety (1.96 ± 1.01). The lowest mean scores were recorded for aggression (0.57 ± 0.54) and obsessive-compulsive behavior (0.42 ± 0.62), consistent with their limited prevalence in this population. Control dogs remained near baseline across all domains. Full categorical distributions are provided in Table 6.

Table 6 Distribution of anxiety-related behavioral scores (C-BARQ) across six domains in anxious dogs (n = 36), with mean scores for the control group (n = 20)

Fig. 3

Correlation heatmaps comparing anxious dogs (n = 36) and control dogs (n = 20). Pearson correlation coefficients (r) are shown for behavioral anxiety subtypes, heart rate, and echocardiographic parameters. Darker shades denote stronger correlations. Asterisks (*) indicate correlations that remained statistically significant after Benjamini–Hochberg false discovery rate (FDR) correction across the family of correlation tests (q < 0.05). Data correspond to Tables 3, 4 and 5

Discussion

This study explored the association between behavioral anxiety and echocardiographic parameters in dogs, revealing measurable cardiac changes linked to chronic emotional stress. General anxiety was significantly correlated with increased fractional shortening (FS%), suggesting a hyperdynamic systolic state likely driven by sympathetic activation, while phonophobia was associated with relatively greater left ventricular diastolic dimensions (LVIDd) and aggression with elevated left atrial-to-aortic root ratios (LA/Ao). These findings parallel human data linking emotional stress to atrial remodeling and arrhythmia risk [11, 12]. In addition, both FS% and ejection fraction (EF%) showed negative correlations with systolic chamber size (LVIDs), consistent with expected physiological relationships, and heart rate correlated strongly with myocardial wall thickness, FS%, and EF%, indicating coordinated contractile changes under heightened arousal (Table 5, Fig. 2). By contrast, none of these associations were observed in the control group, where correlations remained weak and non-significant, reinforcing that the cardiac–behavioral relationships were specific to anxious dogs.

The association between general anxiety and elevated fractional shortening (FS%) observed in this study suggests a hyperdynamic myocardial state consistent with chronic sympathetic nervous system activation. Similar findings are well documented in human psychocardiology, where persistent emotional stress promotes catecholamine release, heightened myocardial contractility, and progressive structural adaptations. The increased FS% in anxious dogs therefore likely reflects autonomic imbalance–mediated cardiac hyperkinesis. The positive correlation between phonophobia and left ventricular diastolic dimension (LVIDd) may provide additional insight, as noise-sensitive individuals exhibited relatively larger diastolic chambers despite the group mean remaining below reference values—likely due to small body size. This pattern could represent early-stage remodeling associated with increased preload or stress-induced dilation. Likewise, the association between aggression and higher left atrial-to-aortic root ratios (LA/Ao) may indicate early atrial remodeling in response to repeated behavioral arousal, though causal inference cannot be drawn from this cross-sectional design. Finally, the strong correlations between heart rate and multiple echocardiographic indices (LVFWs, FS%, EF%) reinforce the biological plausibility of anxiety-driven cardiac remodeling, particularly since these relationships were absent in the control group.

Our findings partially align with existing veterinary literature but differ in emphasizing chronic, naturally occurring emotional stress rather than acute or pharmacological stressors. Most previous work in veterinary cardiology has examined transient stress responses or drug effects, whereas this study evaluated prolonged anxiety in client-owned dogs under real-world conditions. Pradelli et al. (2014) showed that acute emotional stress during echocardiographic handling transiently elevated aortic peak velocity in Boxer dogs, reflecting a hyperdynamic response, which parallels our observation of elevated fractional shortening (FS%; mean 42.14 ± 10.96%), exceeding reference limits in 44.4% of anxious dogs and suggesting sustained sympathetic activation [13]. In contrast, Fries et al. (2019) reported no significant changes in FS% or ejection fraction (EF%) after trazodone administration in healthy cats, highlighting the importance of excluding medicated dogs in our study and underscoring that the higher FS% in anxious dogs is more plausibly explained by chronic anxiety than pharmacological effects [14]. Neuroimaging work by Xu et al. (2023) further supports this interpretation by demonstrating disrupted connectivity in brain regions regulating emotion (e.g., amygdala, hippocampus) in anxious dogs, reinforcing the link between emotional dysregulation and physiological outcomes [15]. Similarly, Wang et al. (2025) identified early myocardial impairment under radiation-induced stress in Beagles using speckle-tracking echocardiography; unlike those dogs, our anxious cases displayed increased FS% and EF%, suggesting that emotional stress may initially induce compensatory cardiac responses before progressing to maladaptive remodeling depending on stressor chronicity [16]. Taken together, these comparisons highlight the novelty and clinical significance of our work, providing evidence that naturally occurring chronic emotional stress can drive subclinical cardiovascular remodeling in dogs, consistent with mechanisms established in human psychocardiology [17,18,19,20].

This study has important implications for veterinary cardiology and behavioral medicine. Traditionally, canine anxiety is addressed through behavioral modification, environmental enrichment, and pharmacological treatment, but our findings suggest that chronic anxiety may also act as a driver of early-stage cardiac remodeling, even in dogs without overt cardiovascular disease. Increases in fractional shortening (FS%), left ventricular internal dimension in diastole (LVIDd), and left atrial-to-aortic root ratio (LA/Ao) observed in anxious dogs indicate that sustained emotional stress can promote subclinical cardiovascular adaptations [21]. Although these parameters generally remained within reference ranges, they may represent compensatory states that precede pathological remodeling. Elevated FS%, present in 44.4% of anxious dogs, likely reflects sympathetic dominance which, in predisposed individuals or breeds, could progress to hypertrophy or diastolic dysfunction. By contrast, control dogs remained within normal limits, reinforcing that these changes were specific to anxiety rather than incidental variation.

Integrating standardized behavioral screening tools such as the validated C-BARQ into routine veterinary practice may therefore support early identification of dogs at risk, particularly those with high scores for general anxiety, phonophobia, or aggression. Such individuals could benefit from proactive cardiac monitoring, including serial echocardiography, to enable timely intervention. Importantly, clinicians should interpret echocardiographic findings in the context of behavioral status: functional hyperkinesis or mild atrial enlargement in reactive dogs should not be automatically attributed to primary cardiac pathology [3]. Recognizing the influence of emotional stress on cardiac function can improve diagnostic accuracy, guide treatment decisions, and help avoid unnecessary pharmacological interventions.Ultimately, these findings support a more integrated veterinary approach that combines behavioral and cardiac assessments. Such a holistic model could facilitate earlier, targeted interventions and improve both emotional and cardiovascular health in companion animals.

Despite providing novel insights, this study has several limitations. Although a control group of clinically healthy, non-anxious dogs was included, it was not fully matched to the anxious cases in age, body size, or breed distribution. These differences may partly explain some echocardiographic findings and limit attribution solely to anxiety. Breed predispositions—particularly in Shiba Inus and Maltese—may also have influenced baseline cardiac metrics. Reliance on owner-reported C-BARQ data, while validated, introduces subjectivity and potential reporting bias. The relatively small sample size (36 anxious, 20 controls) limits statistical power and generalizability, while the cross-sectional design prevents causal inference. In addition, multicollinearity among anxiety subtypes was not formally assessed and may have contributed to overlapping variance.Interpretation of echocardiographic parameters against fixed reference ranges is another constraint, as more than half of the anxious dogs weighed < 3 kg. Size-related misclassification is therefore possible, particularly for LVIDd, and future work should employ size-indexed indices (e.g., LVIDDN) to improve accuracy. An unexpected positive correlation between heart rate and LVIDd also emerged, which runs counter to physiological expectations. This paradox may reflect allometric scaling in very small dogs, confounding by anxiety severity, or measurement variability in fast heart rates, and should be regarded as exploratory pending replication in larger, size-matched case–control groups.Finally, the absence of electrocardiographic (ECG) data represents a significant limitation. Although rhythm abnormalities were suspected in nearly half of the anxious dogs, their classification remained provisional, based only on auscultation and echocardiographic impressions. Future studies should address these limitations by enrolling larger, multicenter case–control groups with matched controls, using longitudinal designs to explore temporal relationships, incorporating objective stress biomarkers (e.g., heart rate variability, serum cortisol, salivary alpha-amylase), and applying advanced imaging modalities such as tissue Doppler or speckle-tracking echocardiography. Interventional studies assessing whether behavioral therapy or anxiolytic medications can mitigate anxiety-related cardiac changes would also provide clinically relevant guidance for optimizing both emotional and cardiovascular health in dogs.

Conclusion

This study provides novel evidence that chronic behavioral anxiety in dogs is associated with measurable alterations in cardiac structure and function, including elevated fractional shortening, increased left ventricular dimensions, and higher LA/Ao ratios. These findings suggest that persistent emotional stress may promote early, subclinical cardiac remodeling even in the absence of overt heart disease. Recognizing anxiety as both a behavioral and cardiovascular condition underscores the importance of incorporating standardized behavioral assessments into routine veterinary care. Although limited by sample size and the absence of fully matched controls for breed and body size, the results highlight the need for larger, longitudinal studies incorporating objective stress biomarkers to clarify causality and disease progression. Such work could refine early diagnostic strategies and support preventive interventions. Ultimately, addressing anxiety as a systemic condition may improve both emotional well-being and long-term cardiovascular health in companion dogs.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author (Dr. Mohammad Molazem) on reasonable request.

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AVMA I News – Why persistence pays off when it comes to dietary management of chronic enteropathy patients

Prescribing therapeutic diets involves not only evaluating ingredients, but also strong client communication

Story by Malinda Larkin

October 20, 2025

If a patient is vomiting, has diarrhea, or is showing other gastrointestinal (GI) clinical signs, dietary management should automatically be on the table, says Dr. Adam Rudinsky, associate professor in the Department of Veterinary Clinical Sciences at The Ohio State University College of Veterinary Medicine.

He runs a laboratory dedicated to researching chronic enteropathies, pancreatic and hepatic disease, and intestinal microbiome. Dr. Rudinsky will be the first to acknowledge that getting owners to switch diets can be difficult.

“A diet switch is like a personal affront to people,” Dr. Rudinsky said. “A lot of their self worth, in terms of that animal, is tied up in the diet that they feed them. So, it can be a challenging discussion, particularly when you have a busy schedule.”

Taking a comprehensive diet history and making a purposeful diet selection are the keys to success when it comes to a nutritional management strategy, says Dr. Adam Rudinsky, associate professor in the Department of Veterinary Clinical Sciences at The Ohio State University College of Veterinary Medicine. He gave a lecture on the topic at the 2025 American Animal Hospital Association annual conference.

But he maintains it’s still worth the time and effort. He and Dr. Harry Cridge, associate professor of small animal internal medicine at Michigan State University College of Veterinary Medicine, each gave presentations on nutrition at the 2025 American Animal Hospital Association CON, held September 11-13 in Chicago. Both are board-certified specialists in small animal internal medicine.

Dietary selection

When considering a dietary management strategy, after taking a diet history, Dr. Rudinsky recommends asking these questions:

• What is the duration of clinical signs—acute or chronic?

• Where are the clinical signs localized? Stomach? Small or large bowel?

• Are the clinical signs consistent with a specific disease process, such as pancreatitis or parvovirus?

If the diagnosis warrants, a diet trial can be the first step, even before a biopsy or other invasive diagnostic procedure. Why? “Because many patients will respond to it and it’s cost effective,” Dr. Cridge said.

Dr. Rudinsky outlined five main diet categories for dogs and cats with acute or chronic GI clinical signs:

• Highly digestible or low-residue diets: These diets take the work off the GI tract by requiring less digestive effort. Dr. Rudinsky uses these diets for dogs and cats that are underweight due to vomiting, mild small intestine disease, or acute GI disease because of their nutritional density.

• Novel or limited-ingredient diets: Often associated with use in chronic GI disorders, especially small or large bowel disease, these diets can also help with food allergies. However, Dr. Rudinsky says the prevalence of food intolerance appears to be much higher than the true food allergy, as most animals are responding to the antigen load. “If you continue to feed a diet that is too rich or varied, you can get those responses frequently that appear as a chronic condition,” he said. When selecting a limited-ingredient diet, he advises choosing one with only a single carbohydrate and a single protein source in the ingredient list, both of which are ideally novel to the patient.

• Hydrolyzed diets: These diets undergo hydrolysis processing to reduce allergenicity and antigenicity by altering macronutrient structure. Typically, they are highly digestible and have a reduced fiber content. Often these are a mainstay for chronic GI symptoms, such as pancreatitis in cats and small bowel disease in dogs and cats. Specifically, Dr. Rudinsky said, “The more I have a vomiter … or a small bowel diarrhea case, I love a hydrolyzed diet.”

• Low-fat diets: These are diets with fat content generally in the range of less than 3 grams of fat per 100 kilocalories. More recently, fat content has been identified as an important component in the management of some canine GI diseases, especially pancreatitis, GI motility issues, or mixed bowel diarrhea cases, Dr. Rudinsky said. This doesn’t appear to be an issue for cats. However, “for dogs, if you use an easily digestible diet, you might as well use one that is low fat too,” he added.

• Fiber-enriched diets: Fiber is added to diets for multiple reasons, but especially diarrhea and large bowel disease in both dogs and cats. The fiber type and source will influence the type of effect that is seen in the patient. The benefits of soluble and insoluble fiber, besides helping with diarrhea (soluble) or constipation (insoluble) include fermentation, production of volatile fatty acids, benefits to enterocyte health, augmentation of the microbiota, as well as alterations in gut motility and passage of GI luminal contents.

When first getting started, Dr. Rudinsky recommends looking at hydrolyzed, novel protein, or easily digestible diets for cats. “Cats maintain the same response rate with easy digestible diets that they do with hydrolyzed and novel ingredient diets, but dogs do not,” he said, so only start with hydrolyzed or novel ingredient diets for dogs.

Dr. Harry Cridge, associate professor of small animal internal medicine at Michigan State University College of Veterinary Medicine, says he uses soluble fiber to control diarrhea and insoluble fiber to control constipation.

Also important to note is that even among a particular diet category, options can vary by ingredient list, fiber content, fat content, and more. For example, Dr. Cridge says elimination diets differ in more than just their protein. He recommends using product guides for up-to-date nutrient compositions, including looking at dietary fat and fiber content.

Both Drs. Rudinsky and Cridge suggest looking at the global nutrient profile of diets when evaluating macronutrient diet choices. Do not focus on percent as fed, which doesn’t take into account water content and other features of the diet, but rather look at grams per 100 kcal, Dr. Rudinsky said.

This information may not always be on the bag. In that case, they recommend using Tuft University Cummings School of Veterinary Medicine’s Clinical Nutrition Service Nutrient Calculator or product guides to help with comparing nutrients between diets.

Dedication pays

Recent research reaffirms the importance of purposeful nutritional management, especially for patients with chronic enteropathies.

A retrospective paper published this past May in the Journal of Veterinary Internal Medicine (JVIM) looked at 81 dogs with chronic enteropathy. Among those in which the only therapeutic change was a hydrolyzed or other alternative diet, 88% (14 of 16) had a decreased stool‐consistency score and 70% (16 of 23) saw a 69% reduction in their total Canine Inflammatory Bowel Disease Activity Index score.

Another study, published in the September-October 2024 issue of JVIM, followed 60 dogs with chronic inflammatory enteropathy for two years. The initial dietary response rate was about 45%, but over time, 73% of them ended up being diet responsive and able to come off modulators.

“Giving more evidence that even if you don’t get that initial dietary response, diet is still a fundamental component, because your ability to minimize medications later on is going to be super useful,” Dr. Rudinsky said.

Finally, he emphasized the importance of taking a complete diet history. A study out of the University of Zurich, published in 2022 in the journal Animals, found that dietary information gained from referring veterinarians and owners was often incomplete.

Among these dogs presenting to the university’s GI and internal medicine service, no dog had received more than one previous diet trial for chronic GI signs.

After prescribing all of the dogs a new diet, 58% had an initial dietary response. Then the researchers convinced all the owners with a dog that didn’t respond to switch to yet another diet, and those dogs saw a 66% dietary response rate. The researchers did this again and had a 44% dietary response rate for owners that had switched a third time.

“If you add those percentages up … they were able to drive their response rate up in chronic enteropathy animals up to 85% or 86%. So that is really powerful, especially if you think of those dogs that we’ve managed sometimes with super bad prednisone effects or other issues with chronic medications (to correct that).”

“A lot of us intuitively know this, but we’re so thankful if an owner even does one diet switch,” Dr. Rudinsky said. “Don’t be afraid to ask them to switch again if first switch isn’t working.”

So, when to switch? Dr. Rudinsky says, “If you have not seen a response in two weeks, you can abandon ship and switch. If you see a partial response at that two-week mark, then you want to go out to about four weeks.”

Dr. Cridge says two weeks for him, too, and then he’ll move onto another diet for canine patients. “I don’t push owners to try a diet for too long because that’s when they want to give up and try something else,” he said. For cats, he acknowledges the challenge is getting them to try the diet in the first place.

Another issue Dr. Rudinsky has noticed, beyond not convincing an owner to do a diet trial, is getting them to accept the cost of the new diet because many of them may be more expensive than what they are currently feeding their pet.

Finally, Dr. Cridge recommended referring patients to a board-certified veterinary nutritionist when there is a refractory case of chronic enteropathy or protein-losing enteropathy (PLE), presence of concurrent diseases, picky dogs that may need a home-cooked diet, or when owners wish to make a home-cooked diet.

“Nutritionists are invaluable resources, especially for refractory chronic enteropathy and PLE dogs and often will provide remote consultations directly,” he said.

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AVMA I News – Benchmarking data plus elevating efficiency equals practice productivity

Benchmarking data plus elevating efficiency equals practice productivity

AVMA Economist Frederic B. Ouedraogo provides practice data to help with benchmarking

By Malinda Larkin

October 15, 2025

U.S. veterinary practices averaged about $1.5 million in gross revenue in 2024, but adjustment for inflation shows only modest growth in this metric since 2016.

 Another sobering trend: The average number of active clients per practice has been declining since 2019 by about 95 clients per year, to a total of 3,351 clients in 2024. Over the same period, the average number active clients per full-time equivalent (FTE) veterinarian has declined by 15 clients per year, to a total of 1,499 in 2024.

 In 2023, there were 34,296 veterinary practices, according to the U.S. Census Bureau. On average, approximately 362 new veterinary practices have been added each year since 2010, for an annual growth rate of 1.3%.

In 2023, there were 34,296 veterinary practices, according to the U.S. Census Bureau. On average, approximately 362 new veterinary practices have been added each year since 2010, for an annual growth rate of 1.3%.

To help create stronger and profitable practices, Frederic B. Ouedraogo, PhD, senior economist and associate director in the AVMA Veterinary Economics Division, encouraged practice owners to create their own data assets to evaluate the health of their own practice and engage in benchmarking analyses.

 “This allows us to gain insights into our practice performance, monitor our performance over time and against our peers, enabling us to identify our strengths and weaknesses. More importantly, it allows us to learn things that others are doing,” he said.

 Dr. Ouedraogo presented data from the 2025 AVMA Veterinary Practice Owners Survey during his talk “Unlocking Practice Health: Examining the Latest Practice Health Data” at the 2025 AVMA Veterinary Business and Economic Forum, held October 8-9 in Denver.

One of the key metrics for assessing operational efficiency in veterinary practice is gross revenue per square foot, which in 2024 was $538 per square foot on average.

 “This is how much revenue each practice generates per square foot and is a good indicator of practice health,” he said, adding that this figure is especially helpful for comparison because it can be done with any other kind of practice, regardless of size. “Removing bottlenecks will result in greater efficiency and increase gross revenue per square foot.”

 Rate of technology utilization in veterinary practice

Optimizing practice resources, including space and workforce, and removing inefficiencies in systems and processes, such as adopting new technologies, can help veterinary practices boost productivity and revenue, says Frederic B. Ouedraogo, PhD, senior economist and associate director in the AVMA Veterinary Economics Division.

Other productivity metrics from the survey are as follows:

Gross revenue per exam room: This is total revenue divided by the number of exam rooms in the practice. In 2024, U.S. veterinary practices generated $444,668, on average, per exam room per year. Inflation-adjusted (real) revenue per exam room has been trending down since 2020.

Gross revenue per FTE veterinarian: In 2024, the average veterinary practice generated $554,982 per veterinarian, down in inflation-adjusted terms from nearly $600,000 in 2019. Revenue per veterinarian per hour averaged $288 in 2024. “According to our data, veterinarians spend about 30 minutes per patient and complete about 15 scheduled appointments per day, on average, under normal circumstances,” Dr. Ouedraogo said.

Patients per veterinarian per day: The average veterinary practice saw 15 patients per day in 2024, compared with 16.6 in 2021, which he noted may have been unusually high during the pandemic. “If demand for veterinary services slows down, no matter how efficient you are, you will see fewer patients. So it can be a market-related issue, but let’s make sure that our systems and processes are as efficient as they can be, and again, ways to increase efficiency include but are not limited to optimizing your space, empowering your staff through training, and adopting cutting-edge technology that could boost productivity,” he said.

Veterinary practice space utilization: The average veterinary practice measured 3,845 square feet and had 3.5 exam rooms in 2024. The number of FTE veterinarians per exam room was 0.92. “It should be 0.5 or so, allowing one veterinarian to go from one room to another without waiting for the exam room to be ready for next patient,” Dr. Ouedraogo said.

Veterinary practice staffing numbers: The average veterinary practice reported 2.76 FTE veterinarians, which has varied between 2.5 and 2.8 since 2019. In addition, practices averaged 3.7 nonmedical staff members plus 5.74 veterinary technicians and veterinary assistants. But these numbers depend on the species, he noted. Companion animal predominant and exclusive practices averaged a little more than 2.6 FTE veterinarians, 6.35 FTE veterinary technicians and veterinary assistants, and around 4.1 nonmedical staff. Food animal and equine practices had between 3.34 and 2.56 FTE veterinarians, 1.55 and 2.6 veterinary technicians and veterinary assistants, and 1.25 and 1.45 nonmedical staff. Overall, the medical staff-to-veterinarian ratio was 2.21:1 in 2024.

Dr. Ouedraogo encouraged attendees to use the statistics derived from that survey as benchmarks to identify areas for improvement and drive better performance.

He added, “Keep in mind that your PIMS system may have capabilities to generate [these metrics] for you. Take the time to understand your management software, understand what it can do.”

Results Frederic B. Ouedraogo, PhD, presented at the forum will be published in the 2026 AVMA Report on the Economic State of the Veterinary Profession. The 2025 AVMA Report on the Economic State of the Veterinary Profession is available for AVMA members to download for free, and for a fee of $375 for non-members. This annual report examines the major trends through the lens of veterinary education, veterinary employment, and veterinary services.

For more practical advice from the “Unlocking Practice Health: Examining the Latest Practice Health Data” session at the 2025 AVMA Veterinary Business and Economic Forum, take a look at the 3-2-1 Insight-to-Action Guide created on the topic.

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