Evidence for Iron Age horse use from skeletal pathology and dental wear

Photographs of the preserved upper (premolar (p 2–4) 

and molar (m 1–2) teeth) and lower premolar tooth 

showing wear patterns. Red arrows indicate 

areas of extensive tooth wear. © Karastoyanova et al 2026

      The study of ancient horse remains provides valuable insight into how humans first used and managed horses.

Archaeological discoveries, particularly well-preserved skeletons, can reveal signs of riding, traction, or other forms of domestication.

 

Researchers in Bulgaria, led by Nadezhda Karastoyanova, examined an ancient horse skeleton recovered during excavations at an early settlement site in Chirpan, located in the Thracian Valley. The site contained numerous animal remains found in close association with human activity, suggesting an integrated human-animal environment. The full findings of this study have been published in the International Journal of Paleopathology.

 

Radiocarbon dating places the skeleton in the Early Iron Age, about the 8th century BCE. This makes it one of the few well-documented equine skeletons from this period in Bulgaria, providing valuable insight into early horse use in the region. The relatively complete condition of the specimen allowed researchers to carry out a detailed examination of both the skull and axial skeleton. Such a high level of preservation is essential for identifying subtle indicators of human-horse interaction, including evidence of management, workload, and possible domestication practices.

One of the most significant findings was unusual wear on the horse’s teeth. Patterns of wear on the premolars were consistent with what is often described as “bit wear,” caused by repeated contact with a bridle and bit placed in the horse’s mouth. This type of wear typically appears as smoothing or bevelling on the anterior edges of the teeth and is widely regarded as evidence of human control, particularly in ridden or driven horses.

 

The presence of dental wear suggests that this horse may have been accustomed to carrying a rider or being directed through reins. While alternative explanations such as natural abrasion must always be considered, the pattern and location of the wear strongly support the interpretation of deliberate bit use. This provides important evidence for early horsemanship practices.

Examination of the vertebral column revealed several notable pathological changes. These included periosteal bone proliferation, spondylopathic alterations, and partial fusion between adjacent vertebrae. Together, these features indicate a chronic condition rather than an acute injury.

 

Periosteal bone proliferation reflects the body’s response to repeated stress, leading to new bone formation along the vertebrae. Spondylopathic changes suggest degeneration of the spinal joints, often associated with long-term mechanical loading. Partial vertebral fusion represents a more advanced stage, where the spine becomes less flexible due to the joining of vertebrae.

 

These changes are consistent with prolonged biomechanical strain acting on the horse’s back. Rather than resulting from a single traumatic event, the lesions point to repeated loading over an extended period. In modern contexts, similar patterns are often associated with ridden horses, pack animals, or those used for draught work.

When considered together, the dental and skeletal evidence provides a compelling picture of how this horse may have been used. The presence of bit wear suggests active human control, while the spinal changes indicate sustained physical demands placed on the animal.

 

It is therefore plausible that this horse was used for riding, carrying loads, or possibly pulling light vehicles or equipment. The chronic nature of the vertebral lesions implies that such activities were performed regularly over the animal’s lifetime. This supports the idea that horses were not only domesticated but also integrated into daily human activities requiring endurance and strength.

 

The combination of dental wear and vertebral pathology in this ancient horse skeleton offers valuable evidence for early human–horse relationships. Bit-related dental wear indicates controlled handling, while spinal lesions reveal the physical impact of sustained work. Together, these findings contribute to our understanding of how horses were used in the past, highlighting their important role in transport, labour, and possibly riding. Such studies continue to deepen our knowledge of domestication and the long-standing partnership between humans and horses.

 

 

For more details, see:

 

Nadezhda Karastoyanova, Petar Stamberov, Stella Nikolova, Petar Leshtakov,

Early Iron Age horse exploitation in Thrace (Bulgaria) inferred from dental attrition and vertebral pathology,

International Journal of Paleopathology,(2026) Vol 52, Pp 119-127,

 

https://doi.org/10.1016/j.ijpp.2026.01.007

Using simple ECG screening to identify racehorses at risk of exercise-induced arrhythmias

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A simple heart test carried out during a horse’s warm-up may help identify racehorses at risk of
developing dangerous heart rhythm problems during exercise. This new research, led by the University of Surrey, highlights how short electrocardiogram (ECG) recordings could be used as a practical screening tool in everyday training.

 

Cardiac arrhythmias (abnormal heart rhythms) are very common in athletic horses. In many cases they are harmless, but some can reduce performance or, in rare cases, lead to collapse or sudden death during exercise. One of the biggest challenges for veterinarians is identifying which horses are at risk before serious problems occur.

 

Traditionally, detecting these issues requires ECG monitoring during high-intensity exercise. However, this can be time-consuming, expensive, and not always practical. The new study suggests that useful information can instead be obtained from short ECG recordings taken at rest or during light exercise, such as a warm-up trot.

 

The research team analysed ECG data from 110 Thoroughbred and Standardbred racehorses in the United States during routine training. These recordings were collected using portable (ambulatory) ECG devices, allowing horses to be monitored while moving freely. From these data, the researchers selected 60-second segments where the signal quality was good and the heart rate was stable, typically between 60 and 100 beats per minute.

 

Rather than simply looking for obvious irregular beats, the researchers used advanced mathematical techniques to assess the “disorderliness” of the ECG signal. This is known as non-linear analysis and includes methods such as entropy and complexity measurements (for example, Lempel–Ziv complexity and Shannon entropy). These techniques examine how predictable or irregular the heart’s electrical activity is, even when the rhythm appears normal (sinus rhythm).

 

The idea behind this approach is that subtle changes in the ECG signal may indicate an underlying tendency to develop arrhythmias later, especially during intense exercise. In other words, the heart may show early warning signs before any abnormal beats are visible.

 

To test this, the team applied six different algorithms to the ECG data and compared their ability to distinguish between horses that did and did not develop arrhythmias during exercise. The best-performing method achieved an “area under the curve” (AUC) of 0.86. For context, an AUC of 0.5 indicates no better than chance, while 1.0 represents perfect accuracy. Therefore, a value of 0.86 suggests good diagnostic performance.

 

An important finding was that the test was particularly effective at ruling out horses that are unlikely to be at risk. This means it could be used as a first-line screening tool: horses with a negative result could continue normal training, while those that test positive could be referred for more detailed testing, such as a full exercising ECG.

 

This approach builds on earlier work showing that similar ECG analysis methods can detect atrial fibrillation, another common arrhythmia in horses. Because these methods work at different heart rate ranges, it may be possible in the future to screen for multiple heart conditions during a single, low-intensity session.

 

Overall, this study demonstrates that short, simple ECG recordings—combined with advanced data analysis—could help identify at-risk horses earlier. This has important implications for improving both performance monitoring and the safety and welfare of racehorses.

 

 

For more details, see:

 

Vadim Alexeenko, Hamid Tavanaeimanesh, Freya Stein, Jenifer Gold, Lauren Hughes, Molly McCue, Celia Marr, Sian Durward-Akhurst & Kamalan Jeevaratnam 

Detection of exercising ectopic atrial and ventricular beats using non-linear analysis of clinically normal racehorse electrocardiograms at rest or low-intensity exercise. 

Sci Rep (2026). 

https://doi.org/10.1038/s41598-026-41281-0

Vets with Horsepower 2026 tour

            

A unique group of equine vets is once again combining education, adventure, and fundraising to make a difference
- both within the horse world and far beyond it.

 

Known as Vets with Horsepower, this UK-registered charity is made up of experienced equine veterinarians and lecturers who share not only a passion for improving horse health, but also a love of motorbikes. Over the years, they’ve turned that shared enthusiasm into something impactful: travelling long distances by motorcycle to deliver continuing professional development (CPD) lectures, raising money for charitable causes along the way.

 

Their approach may sound unconventional, but it has proven highly effective. By bringing high-quality veterinary education directly to audiences across different countries, and streaming it online globally, they’ve built a strong following while supporting important initiatives worldwide.

 

In June 2026, the team will take on another ambitious journey, travelling through Germany, Poland, Latvia, and Estonia. Along the route, they will deliver a series of expert-led equine lectures, available both in person and via an online platform in exchange for a modest donation.

 

For horse owners, vets and students, the lecture programme offers a valuable opportunity to learn from leading specialists on topics that directly impact equine health and welfare. Sessions will cover a wide range of practical subjects, including early warning signs of cancer, heart conditions in horses, laminitis diagnosis and treatment, broodmare and foal care, headshaking, limb deformities in foals, neurological conditions, hoof health, and even horse welfare in sport.

 

While the content is rooted in veterinary science, much of it is highly relevant to everyday horse ownership: helping owners better recognise early signs of illness, understand common conditions, and make more informed decisions about their horse’s care.

 

At the heart of the initiative is a strong charitable mission. Funds raised from the lectures will support several causes, including projects helping children in Ukraine recover from trauma, supporting veterinary care for horses in conflict zones, protecting wildlife affected by poaching in Africa, and improving the welfare of working horses and donkeys in countries such as The Gambia. Additional efforts focus on creating better opportunities for children in Malawi.

 

Importantly, the group is also committed to accessibility. Free webinar access is available for horse owners, vets, and students in Ukraine and developing countries, ensuring that knowledge can be shared where it is needed most.

 

For more details, see

 

https://www.vetswithhorsepower.com/2026.html

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

Grayson-Jockey Club Research Foundation project funding announced

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 The Grayson-Jockey Club Research Foundation has approved $1,835,879 to support 13 new
research projects, 13 continuing projects at 16 universities, and three career development awards. This brings Grayson’s total investment since 1940 to more than $45.8 million, funding over 466 projects at 50 universities.

“Grayson remains deeply committed to research that supports every horse, no matter the breed or discipline,” said president Jamie Haydon. “We’re also pleased to expand our career development awards to $30,000, thanks to the generosity of Lucy Hamilton and the Klein Family, and to honor the late Edward Bowen with a dedicated award.”

The 2026 research portfolio spans infectious disease, diagnostics, performance, reproduction, and injury prevention.

Several projects target infectious disease, including Rhodococcus equi, a leading cause of pneumonia in foals. Researchers at Baylor College of Medicine will study how equine lung cells respond to infection to aid vaccine development, while Iowa State University will evaluate hyperimmune plasma as a preventive strategy to reduce disease and antibiotic resistance.

Improved diagnostics are another priority. Louisiana State University is advancing a more sensitive test for nocardioform placentitis, and Texas Tech University is developing rapid field and laboratory tests for contagious equine metritis. At the University of California, Davis, researchers aim to create definitive diagnostic tools for equine neurodegenerative diseases.

Novel therapies are also under investigation. Michigan State University is exploring IFNL3 mRNA as a treatment and vaccine booster for equine herpesvirus-1, while Oregon State University is developing phage therapy for chronic wound infections.

Performance and welfare-focused studies include research at Texas A&M AgriLife on tendon biology to better understand overuse injuries, and at the University of Minnesota on ECG screening to detect cardiac-related poor performance and reduce sudden death in racehorses. The University of Bern will assess a new surgical approach for trigeminal-mediated headshaking.

Metabolic and reproductive health are also addressed, with Cornell University examining the role of bile acids in infertility linked to equine metabolic syndrome.

Finally, two projects at the University of Queensland will investigate gastric health, including acid rebound and the effects of feeding strategies during exercise, with the aim of improving management and reducing gastric disease risk.

Together, the funded projects highlight Grayson’s ongoing commitment to advancing equine health through impactful research.

Details on the new projects are available at the following link:

 grayson-jockeyclub.org/default.asp?section=2&area=Research&menu=2

IVF progress

  

Researchers from the University of Florida Department of Animal Sciences have reported
progress in equine reproduction, demonstrating that frozen-thawed stallion sperm may be more effective for in vitro fertilisation (IVF) than fresh or chilled semen. The findings, published in the journal Reproductive Biology, could have significant implications for the performance horse industry.

In horse breeding, IVF has historically lagged behind its success in other species such as cattle. One major challenge has been the difficulty of achieving proper sperm function outside the body. In particular, stallion sperm require a process known as capacitation before they can penetrate and fertilise an egg. This involves a series of physical and biochemical changes that are highly sensitive to environmental conditions such as temperature and time.

The need for improved IVF techniques is especially relevant in the performance horse sector. Highly valuable mares are often selected for breeding, but not all are able to safely conceive or carry a pregnancy. Certain conditions, including uterine disease, prior foaling injuries, or lameness, may increase the risk associated with pregnancy. Additionally, some mares may be performing at their optimal level and cannot be withdrawn from competition for breeding purposes.

In such cases, producing an embryo via IVF and transferring it into a surrogate mare offers a safer alternative, protecting both the donor mare and the developing foal.

To better understand how to achieve successful fertilisation, the research team investigated how different types of semen - fresh, chilled, and frozen-thawed - respond under capacitating conditions. They also compared various sperm selection methods, including Percoll gradients, Swim-Up techniques, and microfluidic systems*. These approaches were assessed based on key indicators such as sperm motility, acrosome integrity, and biochemical markers like tyrosine phosphorylation.

The results revealed that temperature played a critical role. Incubating sperm at body temperature (38°C) reduced motility, whereas maintaining sperm at ambient temperature allowed optimal capacitation within approximately four hours. At this time point, sperm also showed the highest level of acrosome integrity, an important factor for successful fertilisation.

The research team found that frozen-thawed sperm performed better than fresh or chilled samples in the IVF setting. Although freezing and thawing can place mild stress on sperm cells, this stress appears to trigger changes that promote capacitation. As a result, frozen sperm were able to function effectively with fewer preparatory steps.

Further experiments confirmed fertilisation success through the observation of pro-nuclear formation and early embryo development. Notably, microfluidic sperm selection produced superior results compared to traditional Swim-Up methods, improving sperm quality and fertilisation potential.

Beyond the biological findings, the use of frozen sperm offers practical advantages. Unlike chilled semen, which must be used within a short timeframe, frozen semen can be stored indefinitely and thawed when needed. This flexibility allows veterinarians and breeders to better coordinate the timing of egg collection and fertilisation, making the IVF process more efficient and accessible.

This research represents a significant step forward after more than three decades of limited progress in equine IVF. By identifying conditions that support effective capacitation and demonstrating the advantages of frozen sperm, the study provides a foundation for improving embryo production in horses. For the equine industry, these advances could expand breeding options while prioritising the health and welfare of valuable mares.

 

For more details, see:

Joao D. de Agostini Losano, Jillian E. Guertin, Maura S. McGraw, Lana Katz, Vilceu Bordignon, Justin W. Callaham, Jose H.F. Pontes, Perla Fleury, Marc Maserati, Carly Turner, Bradford W. Daigneault,

Temporal characterization of conditions that promote functional capacitation of stallion sperm,

Reproductive Biology (2026) Vol 26, 2,101201,

https://doi.org/10.1016/j.repbio.2026.101201

 

 

*Percoll gradient centrifugation is a method that separates sperm based on their density. A liquid medium is layered in tubes at different concentrations, and the semen sample is placed on top. When the tube is spun in a centrifuge, sperm cells move through the layers depending on their density and quality. The most viable sperm - those that are motile and structurally normal - tend to settle into a specific layer, while debris, dead sperm, and less functional cells remain elsewhere. This method is widely used because it produces a relatively clean and concentrated sample of high-quality sperm.

Swim-Up technique relies on sperm motility rather than density. In this approach, a semen sample is placed at the bottom of a tube with a layer of culture medium above it. Over time, the most motile sperm actively swim upward into the medium. These sperm are then collected from the top layer. This technique mimics a natural selection process, as only the strongest swimmers are chosen. However, it can result in lower sperm numbers and may not always select for the best overall sperm quality, especially if motility is reduced.

Microfluidic sperm selection systems represent a more modern and precise approach. These systems, such as microfluidic sperm selection, use tiny channels that mimic aspects of the female reproductive tract. Sperm are introduced into a device where they must navigate through narrow pathways and fluid flows. Only sperm with good motility, proper morphology, and functional membranes can successfully pass through the system. This method reduces mechanical stress on the sperm compared to centrifugation and may better preserve their physiological state.