Study challenges assumptions about “knee chips” in Thoroughbred yearlings

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The discovery of carpal osteochondral fragments (COF), commonly known as “knee chips,” on
pre-sale radiographs has long been viewed as a red flag in the Thoroughbred industry. Horses showing these lesions are often discounted at auction because buyers assume they will be less likely to succeed on the racetrack. However, new research suggests that this long-held belief may not be as straightforward as previously thought.

A study published in the Equine Veterinary Journal by researchers at the University of Kentucky's Maxwell H. Gluck Equine Research Center is the first to directly compare sales and racing outcomes of Thoroughbred yearlings with COF against a matched population of radiographically clean horses. The findings indicate that while the presence of COF can negatively affect both sales and racing performance, arthroscopic surgery may help mitigate some of those disadvantages.

“The idea came from seeing a large number of these cases get significantly marked down in price, just because people assume a chip means the horse won’t perform,” said Bruno Menarim, one of the study’s senior authors. “That was possibly true in the ’80s and part of the ’90s, but not with current arthroscopic surgery approaches.”

Researchers reviewed clinical records from Hagyard Equine Medical Institute between 2015 and 2018 and identified 46 Thoroughbred yearlings with dorsal osteochondral fragments of the radial or intermediate carpal bones. Twenty-six horses underwent arthroscopic removal of the fragments before sale, while 20 were managed conservatively. A control group of 138 sire- and year-matched siblings without radiographic abnormalities was also assembled.

The team then tracked sales and racing records up to June 2023, examining variables including sale price, career earnings, average earnings per start, number of starts, seasons raced, highest speed figure achieved and the highest class of race reached.

Overall, the presence of COF was associated with lower sale prices and reduced lifetime earnings, regardless of treatment. Horses in both the surgical and non-surgical groups also recorded fewer starts and raced for fewer seasons than their unaffected counterparts.

However, important differences emerged when treatment was considered. Horses whose fragments were removed arthroscopically were significantly more likely to achieve a racing career than those managed conservatively. Statistical analysis showed surgically treated horses had more than six times the odds of making it to the racetrack compared with untreated horses.

Perhaps more importantly from a commercial perspective, surgically treated horses were not significantly different from the control group in either sale price or total earnings. In contrast, untreated horses were heavily penalised at auction and earned significantly less during their racing careers.

“In other words, the gap between a surgically treated horse and a clean horse was not statistically significant,” Menarim explained. “The gap between an untreated horse and a clean horse was.”

The researchers also noted that the average difference in sale price between treated and untreated horses was nearly $2,000 - roughly equivalent to the cost of the surgery itself.

The study’s authors caution that the relatively small sample size and single-centre design limit the broader applicability of the findings. Nevertheless, the results suggest that while a history of COF can affect buyer perception, arthroscopic removal may preserve both sales appeal and future athletic potential.

For consignors and owners faced with a yearling diagnosed with a knee chip, the research offers reassurance that the lesion itself need not be career-defining - particularly when modern surgical treatment is employed.

For more details, see:

 

Daria C Debald, Victoria L Stanton, Cole B Sandow, Dwayne H Rodgerson, Michael A Spirito, Robert J Hunt, Bruno C Menarim.

Racing and sales performance in Thoroughbred yearlings after carpal osteochondral fragment removal.

Equine Vet J. 2026;58(3):682–691

https://doi.org/10.1111/evj.14532

Transient hindlimb asymmetry following intramuscular vaccination in horses

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Vaccination is an essential part of preventative healthcare in horses and plays a major role in
protecting equine populations from infectious diseases such as influenza and tetanus. Most vaccines are administered by intramuscular injection, meaning the vaccine is delivered directly into a muscle. Although vaccination is considered safe and routine, mild side effects can occasionally occur.

 

A recent study investigated whether intramuscular vaccination into either the semitendinosus muscle or the pectoralis descendens muscle could temporarily affect a horse’s movement and gait.

 

The semitendinosus is one of the large muscles located in the horse’s hindquarters. It forms part of the hamstring muscle group and contributes to propulsion during movement, particularly when the horse pushes off the ground during walking, trotting, or cantering. Because of its size and accessibility, this muscle is sometimes used as an injection site for vaccines or medications.   The pectoralis descendens (also known as the cranial superficial pectoral muscle) forms part of the ‘thoracic sling’ between the front legs that supports the torso. It is a common site for intra-muscular Injections.

 

The study found that routine intramuscular vaccination into the semitendinosus  resulted  in a “transient, measurable push-off-type hindlimb asymmetry.” In simpler terms, the vaccinated horses showed a temporary unevenness in the way they used their hindlimbs during movement. This asymmetry was most noticeable 48 hours after vaccination but had resolved by 96 hours.

 

A “push-off-type” asymmetry refers to changes occurring during the propulsion phase of movement. During locomotion, the hindlimbs generate the force needed to push the horse forward. If one hindlimb produces less force because of soreness or stiffness, the horse may shift more weight onto the opposite limb. This can create a subtle unevenness in gait that may resemble mild lameness.

 

The asymmetry observed in the study was described as measurable, meaning it could be detected using objective gait analysis techniques. Modern gait analysis often uses motion sensors or inertial measurement units attached to different parts of the horse’s body. These devices can identify very small changes in movement that may not always be visible to the human eye. Such technology is increasingly used in equine sports medicine to improve the accuracy of lameness detection.

 

The research team did not detect any clinically relevant changes in gait symmetry following vaccination into the pectoralis descendens or after saline (control) injection at either site.

 

Importantly, the effect observed after vaccination in the semitendinosus muscle was temporary and short-lived. The horses returned to normal symmetry within four days of vaccination, suggesting that the effect was likely related to temporary muscle soreness or mild local inflammation at the injection site rather than any serious injury. Mild inflammation is a normal immune response following vaccination, as the body reacts to the vaccine and begins developing immunity.

 

This finding is particularly relevant for veterinarians, owners, trainers, and equine therapists because temporary gait asymmetry following vaccination could potentially be mistaken for orthopaedic lameness or poor performance. Horses competing or undergoing lameness investigations shortly after vaccination may therefore show altered movement patterns unrelated to musculoskeletal disease.

 

The study also highlights the importance of appropriate vaccination scheduling. Since measurable asymmetry occurred around 48 hours after injection, strenuous exercise or competition immediately after vaccination may not be ideal. Many veterinarians already recommend a short period of lighter work following vaccination to allow horses time to recover from any mild soreness or systemic effects.

 

Overall, the study suggests that intramuscular vaccination into the semitendinosus muscle may cause short-term hindlimb asymmetry, but the effect appears mild, temporary, and self-resolving in healthy horses.

 

For more details, see:

 

J. Lenarz, I.H. Smit, M. Rhodin, C. Lischer, M.C. Fugazzola,

Vaccination-associated lameness in warmblood horses after intramuscular injection,

Journal of Equine Veterinary Science (2026), Vol 159,105820.

 

https://doi.org/10.1016/j.jevs.2026.105820

Florida study into identifying joint pain

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Horse owners in Central Florida are being invited to take part in a University of Florida study
aimed at improving how joint pain is identified and managed in horses; research that could also have important implications for human medicine.

The project is a collaboration between the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS), College of Veterinary Medicine, College of Dentistry, Department of Biomedical Engineering, and the Pain Research and Intervention Center of Excellence. Funded by the National Institutes of Health, the study focuses on developing better ways to detect pain associated with equine osteoarthritis (OA), one of the leading causes of lameness and reduced performance.

Osteoarthritis is a common condition in horses, particularly those involved in athletic activities such as racing, jumping, or regular trail riding. Repetitive stress on joints, especially the fetlocks, can lead to gradual degeneration. However, by the time a horse shows obvious signs of discomfort, such as lameness, significant joint damage may already have occurred.

Dr. Samantha Brooks, associate professor of equine physiology and genetics at UF/IFAS, says the goal is to shift detection much earlier. Rather than relying solely on visible clinical signs, the research team is testing non-invasive tools to identify subtle indicators of pain.

“We tend to treat symptomatically when horses show obvious clinical signs of pain, but if we can detect subtle joint pain sooner, we might be able to start treatment earlier and better preserve joint function,” Brooks explained. “Horses experience many of the same joint diseases as people, so improving how we measure their pain can also help us better understand arthritis in humans.”

Because horses cannot communicate where or when they feel discomfort, the study aims to develop more objective ways of assessing pain. Researchers will monitor movement patterns and behaviour using new technologies designed to pick up small changes that may otherwise go unnoticed.

The team is currently recruiting horses in Central Florida, particularly those already diagnosed with osteoarthritis in the fetlock joint. Owners of sound horses are also encouraged to participate, as these animals can serve as valuable comparison cases.

Participation is designed to be straightforward and minimally disruptive. Each enrolled horse will receive a free initial screening, including a basic lameness exam, radiographs (X-rays) of the fetlocks, and a blood sample. Researchers will then visit participating farms several times a year over a two-year period to observe horses in their normal environment, without requiring changes to their routine or management.

Owners are asked to complete a short survey, taking around 15 minutes, to determine eligibility. If a horse qualifies, the research team will coordinate directly with the owner to schedule farm visits and assessments.

Ultimately, the research aims to identify early markers of joint pain, enabling earlier intervention and more tailored treatments. For horse owners, that could mean better long-term soundness, improved comfort, and a higher quality of life for their animals.

For more details, see:

https://redcap.ctsi.ufl.edu/redcap/surveys/?s=CEYRXYRJFJ7AHNAR

How Artificial Intelligence could improve fracture detection in horses

Researchers at the Royal Veterinary College (RVC) are exploring how artificial intelligence (AI) could help veterinarians detect fractures in animals more quickly and accurately. Their work has been shortlisted for the STEM for Britain 2026 award and highlights how technology developed for human medicine can also benefit animal health and welfare.

Fractures are a major concern in Thoroughbred racehorses. These injuries can affect both a horse’s welfare and its racing career, and in severe cases they can be life-threatening. Studies estimate that around 10% of racehorses experience a fracture during training, while bone injuries occur in roughly 1.3 per 1,000 starts in flat racing. Because of this risk, early and accurate detection of bone damage is extremely important.

However, diagnosing fractures is not always straightforward. Veterinarians usually rely on radiographs (X-rays) to assess suspected bone injuries. While X-rays are very useful, identifying fractures on these images can be challenging. Small cracks or subtle changes in bone structure may be difficult to see, and image quality or the angle at which the X-ray is taken can also affect interpretation. As a result, there is growing interest in using technology such as AI to support clinical decision-making.

The RVC research team developed an AI system designed to analyse medical images and identify fractures. The study was led by Associate Professor of Statistics Dr Ruby Chang, with the research carried out by Dr Hanya Ahmed. To train the system, the researchers created a large database of images that included 100 equine fracture cases collected from two UK equine hospitals and from published studies. They also included 70 feline fracture cases and around 4,000 human fracture images from a public database.

The AI system works in three stages. First, it identifies the type of medical image being analysed, such as an X-ray, CT scan, or MRI scan. Next, it determines the angle or projection of the image. Finally, it analyses the image to detect whether a fracture is present and to pinpoint its exact location.

One particularly interesting feature of the study is the use of a technique called transfer learning. In transfer learning, an AI model is first trained on a large dataset (in this case, thousands of human fracture images). The knowledge it gains is then adapted to a smaller dataset from another field; in this case, veterinary medicine. Because there are far fewer veterinary medical images available for training, this approach helps overcome one of the main challenges of developing AI systems for animal healthcare.

Using this method, the AI system was able to detect and locate fractures in horses with accuracy levels between 71% and 84%, despite having a relatively small number of equine images to learn from. The system also achieved very high accuracy when identifying image types and projections, reaching more than 96% accuracy in some stages of the analysis.

The results suggest that AI could become a valuable support tool for veterinarians. By helping identify fractures more quickly and reliably, AI-assisted systems may reduce uncertainty in diagnosis and allow treatment to begin earlier. This could improve recovery outcomes for horses and other animals.

The research team is now expanding the project through collaboration with the Hong Kong Jockey Club. The next goal is to investigate whether AI can detect early bone changes before a fracture occurs. If successful, this could help prevent serious injuries in racehorses and improve welfare within the sport.

Although the current study focuses on horses, the approach could also be adapted for other species such as cats, dogs, and potentially humans. Overall, the research demonstrates how advances in AI and medical imaging could play an increasingly important role in the future of veterinary diagnostics.

 

For more details, see:

Ahmed, Hanya T., Dagmar Berner, Qianni Zhang, Kristien Verheyen, Francisco Llabres-Diaz, Vanessa G. Peter, and Yu-Mei Chang. 2026.

Bridging Species with AI: A Cross-Species Deep Learning Model for Fracture Detection and Beyond

Bioengineering 13, no. 2: 213.

https://doi.org/10.3390/bioengineering13020213

Intra-articular corticosteroids and laminitis risk: new insights into metabolic effects of methylprednisolone acetate

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Intra-articular corticosteroid injections are widely used in equine practice for the management of
joint pain and lameness. Despite their clinical benefits, concerns persist regarding the potential for corticosteroid-induced laminitis, particularly following reports of laminitis developing after joint injections. While many joints are injected safely every year, adverse metabolic consequences appear to be relatively uncommon, raising questions about whether specific corticosteroid formulations, dosages, or patient factors influence risk.

One proposed mechanism for corticosteroid-associated laminitis involves systemic metabolic effects following intra-articular administration. Corticosteroids are known to interact with the hypothalamic-pituitary-adrenal (HPA) axis and may interfere with glucose and insulin metabolism. Disruption of these pathways, particularly the development of hyperinsulinemia, is strongly associated with laminitis. However, not all corticosteroids appear to exert identical metabolic effects, and differences between formulations may be clinically relevant.

To address these concerns, Allen E. Page and colleagues conducted a controlled study at the Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky. The objective of the study was to examine the metabolic effects of intra-articular methylprednisolone acetate (MPA) when administered into multiple low-motion joints.

The study population consisted of six 3-year-old mixed-breed geldings from the university’s research herd. All horses were screened approximately five weeks before the investigation and were confirmed to be free of pituitary pars intermedia dysfunction (PPID) and insulin dysregulation. This ensured that any observed metabolic effects could be attributed to treatment rather than pre-existing endocrine disease.

Each horse was randomly assigned to receive either intra-articular MPA or an equivalent volume of saline. MPA was administered bilaterally into the distal intertarsal and tarsometatarsal joints, with a dose of 20 mg per joint for a total of 80 mg. Serial blood samples were collected to measure resting adrenocorticotropic hormone (ACTH), cortisol, insulin, and glucose concentrations. In addition, repeated low-dose oral sugar tests were performed to assess post-challenge insulin and glucose responses. After a six-week washout period, treatments were crossed over and the protocol was repeated.

The results demonstrated that intra-articular treatment with a total dose of 80 mg of MPA caused significant suppression of the HPA axis. Specifically, resting ACTH and cortisol concentrations were significantly decreased between four and twelve hours following MPA injection. This finding confirms that even intra-articular administration of corticosteroids can produce measurable systemic endocrine effects.

Importantly, however, no significant changes were observed in resting insulin or glucose concentrations. Furthermore, insulin and glucose responses to oral sugar testing at 2, 7, and 14 days post-treatment were not affected by MPA administration. These findings contrast with previous reports involving other intra-articular corticosteroids, which have demonstrated post-injection hyperinsulinemia.

The authors conclude that, in metabolically normal horses, an intra-articular dose of 80 mg of MPA does not appear to induce clinically significant disturbances in insulin or glucose regulation. This observation may help explain the reported practitioner sentiment that MPA carries a lower risk for corticosteroid-induced laminitis compared with other formulations.

Nevertheless, the study’s findings should be interpreted cautiously. The horses involved were young, healthy, and free of known endocrine disease. Additional research is needed to determine whether similar results would be observed in insulin-dysregulated or laminitis-prone horses. Until such data are available, intra-articular MPA should not be assumed to be universally safe in higher-risk populations, despite its apparently favourable metabolic profile in healthy individuals.

  

For more details, see:

Page, A. E., McPeek, J. L., Carattini, S., McGreevy, E., & Adam, E. (2025). 

Intra-articular methylprednisolone acetate does not induce hyperinsulinemia or hyperglycemia in metabolically normal horses. 

Journal of the American Veterinary Medical Association (2025). 

 https://doi.org/10.2460/javma.25.08.0566

Ageing, blood supply and tendon health: new research

Photo: RVC

 Tendon injuries are one of the most common causes of lameness and loss of performance in
horses, particularly as they get older. 

A new study from the Royal Veterinary College (RVC) has shed important light on why ageing tendons are more vulnerable to injury and slower to heal, by closely examining how the tendon’s blood supply changes with age.

 

Tendons are specialised tissues that transmit force from muscle to bone. To do this efficiently, they are dense and tightly packed with collagen fibres. While this structure is excellent for strength and elasticity, it comes at a cost: tendons have relatively few cells and a limited blood supply compared with other tissues.

 

Blood vessels are vital for delivering oxygen and nutrients, removing waste products and supporting repair after microscopic damage caused by normal exercise. Because tendons are already poorly supplied with blood, any further reduction can seriously limit their ability to maintain healthy tissue and to heal after injury.

 

The study focused on the superficial digital flexor tendon (SDFT) in horses. This tendon is frequently injured in athletic horses and is considered the functional equivalent of the human Achilles tendon. This makes the horse an excellent model for understanding tendon ageing in both veterinary and human medicine.

 

The research team, led by Dr Nodoka Iwasaki, Postdoctoral Researcher, and Dr Chavaunne Thorpe, Lecturer in Basic Sciences at the RVC’s Department of Comparative Biomedical Sciences, used advanced 3D technologies (micro-computed tomography (μCT) and confocal microscopy) to capture detailed images of tendon tissue from young (2-5 years old) and older (18-22 years old) horses, enabling them to visualise and quantify the tendon’s vascular network in unprecedented detail. 

 

This approach allowed the researchers to map the tendon’s microvasculature in unprecedented detail.

 

The μCT analysis showed striking age-related changes in the tendon’s blood vessels, particularly within the interfascicular matrix (IFM)  (the region between tendon fibre bundles that is important for tendon elasticity and repair.)

 

In older horses, compared with younger ones, there was:

·      70% reduction in total vascular volume

·      30% reduction in average vessel diameter

·      74% reduction in vessel density

 

In simple terms, older tendons had far fewer and smaller large blood vessels. This leads to significantly reduced blood flow, helping to explain why older tendons are more prone to degeneration and slower to heal.

 

At the same time, the immunolabelling studies revealed something unexpected. Markers associated with endothelial cells (cells lining blood vessels, identified using von Willebrand factor, VWF) and pericytes (support cells that stabilise small blood vessels ) were increased in aged tendons. 

 

This suggests that new, very small blood vessels (capillaries) are forming. However, these new vessels appeared disorganised and were not accompanied by healthy larger vessels. The researchers also found major reductions in markers associated with mature, functional vessel walls (such as MYH11 and desmin), indicating a loss of normal vascular structure.

 

Taken together, the results suggest that ageing tendons lose their well-organised, larger blood vessels and attempt to compensate by forming many small, immature vessels.

 

This disorganised angiogenesis may be driven by low-level inflammation or repeated micro-damage over the horse’s lifetime, but further research is needed to confirm this.

 

Crucially, these new small vessels may not function effectively, meaning they do not adequately restore blood flow or support proper healing.

 

This research helps explain several real-world observations:

·      Older horses are at higher risk of tendon injury

·      Tendon injuries in older horses heal more slowly

·      Re-injury rates are high due to poor-quality repair and scar tissue formation

 

Understanding these vascular changes may help:

·      Identify horses at higher risk of injury

·      Tailor training and workload more carefully as horses age

·      Improve rehabilitation strategies by recognising the limits of tendon healing in older animals

 

By identifying specific age-related changes in tendon blood vessels, this study opens the door to new therapeutic approaches. Potential future strategies may aim to:

·      Preserve healthy blood vessels as horses age

·      Improve vascular organisation during tendon healing

·      Enhance regeneration rather than scar formation

 

Such advances could significantly improve outcomes for older horses with tendon injuries and may also translate to better treatments for tendon injuries in people.

 

In summary, this study provides the first detailed 3D picture of how tendon blood supply changes with age. It shows that while older tendons try to adapt, the loss of healthy, functional blood vessels is likely a key reason why ageing tendons are more fragile and slower to heal.

 

For more details, see: 

 

Nodoka Iwasaki, Jack Llewellyn, Jeanne Brown, Danae E. Zamboulis, Elizabeth J. T. Finding, Caroline P. D. Wheeler-Jones, Chavaunne T. Thorpe

Immunolabelling and Micro-Computed Tomography Revealed Age-Related Alterations in 3D Microvasculature of Tendons.

 Aging Cell (2025) e70293.

https://doi.org/10.1111/acel.70293

Participants sought for equine quality of life survey

In a letter to the Veterinary Record, Cory Noble, research associate at pharmaceutical company Zoetis, urged horse owners to complete a short online survey to help learn more about quality of life in horses.

The project, in collaboration with the research team behind VetMetrica, aims to develop a new tool to measure health-related quality of life in horses, focusing particularly on animals living with chronic conditions such as arthritis or laminitis. These conditions can significantly compromise quality of life, and the new questionnaire will help veterinary surgeons assess and monitor how horses are feeling.

 

Prof. Jacky Reid, one of the researchers, explains: “The participation of horse caretakers will help us understand the relevance and clarity of specific horse behaviours. The survey results will support the development and validity of our new measurement tool, especially when used in horses living with chronic conditions like arthritis or laminitis where their quality of life is significantly compromised.”

The researchers add that horse owners and caretakers possess unique insight into equine behaviour and wellbeing, and that their knowledge is essential for ensuring this new assessment tool is accurate, practical, and relevant to everyday equine care.

VetMetrica health-related quality of life instruments have already been developed for dogs and cats through collaboration between Zoetis and the University of Glasgow Veterinary School. These questionnaires are now widely used in clinical practice and research. The current project extends this work to horses, with the goal of providing veterinarians with a reliable tool to monitor and improve equine quality of life.

The research team invite horse owners and carers to contribute to this research and help shape the future of equine healthcare. Completing the survey will directly support the development of a validated quality of life tool for horses.

 

They state that the survey, which is anonymous, will take 15 – 25 minutes to complete. It asks participants to rate the clarity and relevance of different words and phrases used to describe horses when they are well and when they are unwell. Opportunities for feedback and suggestions are provided.

 

For more information and to take part, go to:

 

https://bit.ly/4pjDuSq

Equine health and quality of life research project

Horse owners and caretakers are being invited to participate in a new research project designed
to improve equine health and wellbeing. The project focuses on developing a questionnaire to measure health-related quality of life (HRQL) in horses.

 

Zoetis, in collaboration with VetMetrica, is leading this initiative. The work builds on many years of pain research carried out at the University of Glasgow, where similar HRQL instruments have already been successfully developed for dogs and cats. These tools are now licensed for use by veterinary surgeons in clinical practice and trials, enabling them to monitor how animals are feeling and assess the effects of health conditions on quality of life. Following the success of these tools for dogs and cats, the same approach is now being extended to horses.

 

The researchers explain that their primary focus is on chronic conditions, such as arthritis or chronic laminitis, which are long-term health problems that may persist continuously or flare up periodically. This differs from acute conditions, such as colic or injury, which tend to arise suddenly but are usually short-lived. By concentrating on chronic conditions, the study aims to capture the ongoing impact of these issues on horses’ daily lives and wellbeing.

 

As part of the project, the research team has compiled a list of words and phrases commonly used to describe horses when they are well or unwell. Horse owners are now being asked to complete a survey to help evaluate the clarity and relevance of these terms. Their input will contribute directly to the development of a practical and effective tool for monitoring equine quality of life.

 

“The survey results will support the development and validity of our new measurement tool”, said Prof Jacky Reid, “especially when used in horses living with chronic conditions like arthritis or laminitis where their quality of life is significantly compromised.”

 

All responses are anonymous and used solely for research. 

For more details, see:

https://zoetis.sjc1.qualtrics.com/jfe/form/SV_5mq13ASuyVTAqLc?Q_CHL=qr

 

For further information contact Dr Cory Noble at cory.noble@zoetis.com

UF researchers seeking Central Florida horses for arthritis pain study

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 Do you own a horse with osteoarthritis, especially in the fetlock joint? Researchers at the
University of Florida are inviting horse owners to take part in a new study that could lead to better ways of identifying and managing joint pain — both in horses and in humans.

This research effort is a collaboration between UF’s Institute of Food and Agricultural Sciences (UF/IFAS), the UF College of Veterinary Medicine, the UF College of Dentistry, and the UF Department of Biomedical Engineering. Their goal is to improve how veterinarians detect joint pain in horses before it becomes visibly severe — giving your horse a better shot at long-term joint health and comfort.

Osteoarthritis is a leading cause of lameness and discomfort in horses. Like humans, horses develop arthritis from repetitive stress on the joints — often due to performance activities like racing, jumping, or even frequent trail work. While joint pain in horses is common, it's often not diagnosed until the horse shows clear signs of discomfort. By that point, valuable joint function may already be lost.

Dr. Samantha Brooks, associate professor of equine physiology and genetics at UF/IFAS, says this new study uses a non-invasive screening process designed to catch signs of pain earlier and more objectively than traditional evaluations.

“We tend to treat symptomatically when horses show obvious clinical signs of pain, but if we can detect subtle joint pain sooner, we might be able to start pain treatments in time to better preserve joint function, and tailor that treatment for each horse,” Brooks said. “And our horses undergo a lot of the same joint diseases that we have. Any tools that we can build to better understand the discomfort caused by arthritis in horses gives us a better understanding of arthritis pain in people.”

Because horses can’t tell us when or where it hurts, the UF team is aiming to build a more accurate way to assess pain — something that could ultimately improve not only equine care but also the way doctors understand arthritis pain in humans.

For this field study, UF is recruiting horses already diagnosed with osteoarthritis — ideally in the fetlock joint — who live in Central Florida. Horses enrolled in the study will receive a free initial screening, which includes:

• A basic lameness exam (e.g., walk/trot in a straight line)

• Radiographs (X-rays) of the fetlocks

• A simple blood draw

After the initial evaluation, the research team will make follow-up visits a few times a year over a two-year period. These visits are designed to observe the horses in their usual environment — there’s no change expected in your horse’s routine. Researchers will track movement patterns and behaviors using new, non-invasive technologies to better understand the signs of discomfort.

Kaylee Young, research coordinator in UF’s Animal Sciences department, emphasized how important horse owners are to this work.

“Participating in this study could lead to better pain management and care for not only our horse companions but for people,” she said. “This research could be something that could be life changing not only for horses but for humans.”

Interested in participating?
If your horse meets the criteria and you’d like to be part of this important study, email uf-gallop@ufl.edu with the subject line “Study Participation.” Be sure to include your location and a few details about your horse’s health, including whether they’ve been diagnosed with fetlock osteoarthritis.

Correlation between mild changes on back radiographs and performance

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 Mild radiographic abnormalities of the thoracolumbar spinous processes do not necessarily impair performance in warmblood jumping horses.

Back pain is a well-recognised contributor to reduced performance in sport horses. However, the precise relationship between clinical signs of back discomfort and radiographic abnormalities of the spine remains poorly defined.

A recent descriptive observational study, published in the Journal of Equine Veterinary Science, aimed to characterise radiographic findings of the thoracolumbar spinous processes in actively competing Warmblood show jumpers and to assess any associations with performance outcomes.

The study evaluated 100 Warmblood jumping horses, all competing in 2018, with a median fence height of 1.35 m (mean 1.3 m; range 0.90–1.60 m). All horses included were free from observable lameness and neurological deficits. Lateral radiographs of the thoracolumbar spine were obtained and assessed by four independent observers, who graded each image for the presence and severity (absent, mild, moderate-to-severe) of four specific abnormalities: narrowed interspinous spaces, sclerosis, lucency, and enthesopathy.

Inter-observer agreement was assessed using the Intraclass Correlation Coefficient (ICC), revealing moderate to good consistency across observers.

In addition to radiographic evaluation, signalment, years of competition, current level of performance, and highest career performance level were recorded for each horse. These variables were then analysed for correlation with radiographic findings.

Strikingly, no horse in the study population was entirely free from radiographic abnormalities, highlighting the high prevalence of such changes among active sport horses. Narrowed interspinous spaces and sclerosis were the most commonly observed findings, predominantly located between thoracic vertebrae T15 and lumbar vertebra L1. Enthesopathy was most frequently identified at the withers, specifically between T8 and T13.

Despite the high prevalence of abnormalities, the research team found no significant correlations between radiographic changes and the horse's age, current performance level, or total years of competition (p > 0.05). Interestingly, the highest career performance level showed a weak but statistically significant positive correlation with the presence of narrowed interspinous spaces and sclerosis. These findings suggest that some radiographic abnormalities may not only be tolerated by high-performing horses but could also reflect adaptive or age-related changes without clinical relevance.

In conclusion, mild radiographic changes of the thoracolumbar spinous processes—particularly narrowing of interspinous spaces and sclerosis—were commonly observed in this cohort of active Warmblood jumpers. Importantly, these findings were not associated with impaired performance, indicating that such abnormalities, when mild and absent of clinical signs, may not adversely impact athletic function.

 

For more details, see:

 

M.P. Kerbert, S.S. le Jeune, K.L. Philips, K.L. Shaw, C.A. Erickson, P. Espinosa-Mur,

Mild radiographic abnormalities of thoracolumbar spinous processes are not associated with decreased performance in 100 Warmblood jumping horses in active competition,

Journal of Equine Veterinary Science,(2025)

Vol 147, 105366,           

https://doi.org/10.1016/j.jevs.2025.105366