Enhancing horse safety in training and racing

The Gerald Leigh Memorial Lectures 2023

Article by Adam Jackson MRCVS 

The Gerald Leigh Memorial Lectures, is an annual  gathering devoted to the racing industry and the health and wellbeing of the horses involved.  

This year, equine veterinarians, researchers, students and industry professionals from around the world attended the event, held June 8, 2023, at the historic Tattersalls Sales in Newmarket, England.  

There were insightful and informative lectures that educated the attendants but also instigated a healthy, lively debate on the health and welfare of the training and competing of horses. The underlying theme that was present during the whole event was all members of the conference had a deep passion and commitment to continuously progress and improve on managing the welfare and wellbeing of the horses in the industry, both on and off of the track.  

Two very special guest speakers, Sir Mark Prescott and Luca Cumani, wonderfully illustrated these sentiments as they described their reflections on the improvement and enhancement of horse safety.  

Horse racing may be regarded as an elite sport, and all activities involving horses have an element of risk. All stakeholders in the racing industry must continuously work to ensure that the risks are minimized in order to reduce the number of injuries and fatalities that may occur in training and on the racecourse.  There are now well-publicized concerns regarding the acceptability of exposing horses to risk in racing.  These lectures and all of the attendees embraced the values of the public will so that there can be continued acceptance of horse sports.   

Reducing the Incidence of Fractures in Racing 

Christopher Riggs of The Hong Kong Jockey Club clearly outlined the various strategies to reduce the risk of fractures in racehorses. There are two principal strategies that may used to reduce the incidence of severe fractures in horses while racing and training:

1.Identifying extrinsic factors that increase risk and take action to minimize them. 

An example would be investigating different racing surfaces in order to determine which may provide the safest racing surface. However, studies have provided limited evidence and support for subtle extrinsic factors.

2.Identifying individuals that are at increased risk and prevent them from racing or minimize that risk until the risk has subsided. 

There are many research routes that are being undertaken to identify those horses that may be at a higher risk of fractures. There are investigations involving heritability and molecular studies that may provide evidence of genetic predisposition to fracture. However, Dr. Riggs explained that further understanding of the relationship between genetic, epigenetic and environmental factors is required before genetic screening is likely to be of practical use.  

Pre-race screening of horses by diligent clinical examination is poor at reducing the incidence of fracture. Dr. Riggs described another strategy that may assist with a clinical examination that is the use of biomarkers in blood and urine.  

Unfortunately, the precision to be of practical value has so far remained relatively unrewarding.  Wearable technology that records biometric parameters, including stride characteristics, has shown some promise in identifying horses that are at increased risk of fracture; although Dr. Riggs explained that this work requires further development.  

Finally, Dr. Riggs described both the use and current limitations of  diagnostic imaging in identifying pre-fracture pathology in order to identify a horse at imminent risk of fracture.  He conceded that further knowledge of the significance of the range of abnormalities that can be detected by imaging is incomplete.

Dr. Riggs concluded his lecture by expressing that the implementation of  diagnostic imaging to screen  “high-risk” horses identified through genetic, epidemiology, biomarkers and/or biometrics may be the best hope to reduce the incidence of racing fractures. This field can be advanced with further studies, especially of a longitudinal nature.

Professor Tim Barker of Bristol Veterinary School discussed the need for further investment in welfare research and education. One avenue of investment that should be seriously considered is the analysis of data related to (fatal) injuries in Thoroughbred racing over the last 25 years.  

It was expressed, with the abundance of data that has been collected, that some risk factors would be relatively simple to identify. An encouraging example in the collection and use of data to develop models in predicting and potentially preventing injury has been conducted by the Hong Kong Jockey Club funded by the Hong Kong Jockey Club Equine Welfare Research Foundation. This may provide an opportunity to pilot the use of risk profiling to contribute to decision-making about race entries.  In addition, the results of the pilot study combined with other sources of data may encourage race authorities to mandate the collection of veterinary and training data in order to help in risk mitigation.

Horse racing is an international sport, and there are different governing bodies that ensure racing integrity. However, the concept of social license equestrian sports and Thoroughbred horse racing continues to gain significant public attention.  Therefore, racing governing bodies are increasingly aiming to provide societal assurances on equine welfare. 

Dr. Ramzan of Rossdales Veterinary Surgeons provided an eloquent and clear message during his lecture that race yard veterinarians and trainers are instrumental in ensuring good horse health and welfare and reducing serious injury of the horse both while training or racing, which will provide sufficient trust and legitimacy from the public and society.  This feasible goal can be reached with good awareness of members involved in the care and training of each individual horse and conveying this information and any concerns to their veterinarian.  The veterinarian can also contribute by honing their knowledge and skills and working closely with yard staff in order to make appropriate and better targeted veterinary intervention.   

In the last two decades, there has been an incredible evolution and exciting developments in diagnostic imaging in the veterinary profession. It is believed that these technologies can provide a significant contribution to helping in mitigating fracture risks to racehorses on the course and in training.  

Professor Mathieu Spriet of University of California, Davis, described how these improvements in diagnostic imaging has led to the detection of early lesions as well as allowing the monitoring of the lesions’ evolution.  

He continued by explaining the strengths and limitations of different imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET).  Being one of the leaders in the use of PET in equine veterinary medicine, he presented further insight on how this particular modality provides high-resolution 3-D bone scans while being very sensitive to the identification of bone turn-over prior to the development of structural changes and allowing one to distinguish between active and inactive processes when structural changes are present.  

He concluded his impressive lecture by providing evidence with amazing PET images that the role of imaging is not merely for diagnostic purposes to characterize clinical abnormalities, but can also be used as a screening tool in certain horse populations for fracture risk assessment or for the monitoring of lesions to provide clearance for racing. 

Fractures, due to bone overloading rather than direct trauma occur commonly in Thoroughbred racehorses and are the leading cause of euthanasia on the racecourse. Despite many changes to race conditions, the number of catastrophic fractures has remained relatively static, with approximately 60 horses a year having a fatal fracture during a race in the UK.  

Against this backdrop, there have been great developments in the diagnosis and treatment of fractures in the last 40 years. Prevention of racecourse and training fractures would be ideal so the development of efficacious techniques to screen horses at risk may reduce the incidence and preserve social licensing.  

Dr. Ian Wright

One technique discussed by Dr. Ian Wright of Newmarket Equine Referrals was to help mitigate the impact of racecourse fractures, which would be acute immobilization of racecourse fractures, thus, reducing associated pain and anxiety while optimizing clinical outcome and reducing on course fatality rates. Because of our increased understanding of fracture pathogenesis and their associated biomechanics, effective fracture immobilization has been made possible. The majority of fractures that occur in flat racing and between obstacles in jump racing, are a result of stress or fatigue failure of the bone and not associated with trauma.  

In addition, fractures seen on the racecourse are often found in the same specific sites (i.e., metacarpal/metatarsal condyles and the proximal sesamoid bones of the fetlock) and have repeatable configurations. With this understanding and knowledge, racecourse veterinarians can optimally immobilize a fracture in a logical and pre-planned manner.  

As Dr. Wright expressed, this allows the fracture patient to have reduced pain and anxiety and enable the horse to be moved from the course comfortably so that it can be further examined. Ultimately, this allows the veterinarian and all stakeholders to make effective and judicious decisions for the sake of the horse’s welfare and wellbeing. As Dr. Wright concluded, this benefits both horses and racing.

Dr. Debbie Guest of the Royal Veterinary College discussed a different approach in mitigating the risk of fractures during training and racing by developing novel tools to reduce catastrophic fractures Thoroughbreds. Because it has been found that some horses are more inherently predisposed to fractures than other horses, Dr. Guest and her team have developed a genome-wide polygenic risk score so that one can potentially calculate an individual horse’s risk of fracturing during training or racing compared to the population as a whole.  

This strategy may contribute in identifying genetically high-risk horses so that additional monitoring of the patients can be exercised during their careers and also leading to fracture risk, which are found to be the cause of approximately half of these incidents.  

The system of using DNA testing to identify biological processes that may or may not be present ultimately leading to fracture risk may be a powerful tool in lowering the risk of catastrophic fracture and requires further research and application.

Cardiac events & sudden cardiac death in training and racing

In racehorses, sudden death that is associated with exercise on the racetrack or during training is a serious risk to jockeys and adversely affects horse welfare and the public perception of the sport. It is believed 75% of race day fatalities result from euthanasia following a catastrophic injury. The other 25% of fatalities is due to sudden deaths and cardiac arrhythmias are found to be the cause of approximately half of these incidents. The lectures focused on this area of concern by providing three interesting lectures on cardiac issues in the racehorse industry.  

Dr. Laura Nath of the University of Adelaide, explained the difficulties in identifying horses that are at risk of sudden cardiac death. It is believed that part of the solution to this difficult issue is the further development and use of wearable devices including ECG and heart rate monitors.  

With the use of these technologies, the goal would be to recognize those horses that are not progressing appropriately through their training and screen these horses for further evaluation. This course of action has been seen in human athletes that develop irregular rhythms that are known to cause sudden cardiac death with the use of computational ECG analysis, even when the ECGs appear normal on initial visual inspection.  

Knowing that ECGs and particularly P-waves are used as a non-invasive electrocardiographic marker for atrial remodeling in humans, Dr. Nath recently completed a study on the analysis variations in the P-wave seen on ECGs in athletic horses and found that increases of P-waves in racehorses are associated with structural and electrical remodeling in the heart and may increase the risk of atrial fibrillation (cardiac event).

Dr. Celia Marr of Rossdales Veterinary Surgeons continued the discussion of cardiac disease in both the training and racing of horses. Unfortunately, cardiac disease knowledge does lag compared to musculoskeletal and respiratory diseases when considering the causes of poor performance in racehorses. Due to the fact that cardiac rhythm disturbances are fairly common, occurring in around 5–10% of training sessions in healthy horses in Newmarket and over 50% of horses investigated for poor performance, Dr. Marr expressed the need for further research and investigation in this area.  

In addition, this research needs to determine if there is indeed a link between heart rhythm disturbances and repeated episodes of poor performance and sudden cardiac arrest. ECGs and associated technologies are helpful, but there are limitations such as the fact that rhythm disturbances do not always occur every time the horse is exercised.  Therefore, it would be of great value that a robust criterion is established when evaluating ECGs in racehorses. The Horserace Betting Levy Board has provided funding for investigation by initially exploring the natural history of paroxysmal atrial fibrillation (self-correcting form) to understand risk factors and predict outcomes for affected horses.

Continuing the theme of the lectures on irregular heart rhythms and associated sudden cardiac death (SCD) in training and racing, Professor Kamalan Jeevaratnam described his exciting research in using artificial intelligence (AI) to identify horses at increased risk of developing irregular rhythms that may cause SCD.  

AI is an exciting and rapidly expanding field of computer science that is beginning to be implemented in veterinary medicine. With funding by the Horserace Betting Levy Board and the Grayson Jockey Club Research Foundation, Professor Jeevaratnam of the University of Surrey, has piloted three novel algorithms that help predict horses with rhythm abnormalities through the analysis of horses’ ECGs.  

It was acknowledged that further research is required to develop this technology by using data collected from multiple sources, but the initial results are promising in the development of an useful AI tool to identify horses at risk of SCD and prevent catastrophic events, thus, ensuring the welfare of the horse in racing.

Conclusion

The Gerald Leigh Memorial Lectures was a thoroughly successful and enjoyable event attended by a variety of different members of the horse racing industry. Not only did the lecturers provide interesting and valuable information but also excitement for the future of racing.  It was very clear that all the lecturers and attendees were passionate and committed to the racehorse welfare and wellbeing as well as retaining the social license for an exciting sport.

Thoroughbred Sales Assessment

By Tom O’Keeffe

The Beaufort Cottage Educational Trust Gerald Leigh Memorial Lectures took place this year at the National Horseracing Museum in Newmarket and a host of international and local veterinary specialists and industry leaders were present to discuss the veterinary aspects of the sales selection of the thoroughbred. 

Gerald Leigh was a prominent breeder and racehorse owner until his death in 2002; and his friend and vet Nick Wingfield Digby opened the seminar and introduced the speakers. The Gerald Leigh Charitable Trust has established this annual lecture series to provide a platform for veterinary topics relating to the thoroughbred to be discussed amongst vets and prominent members of the industry. 

Sir Mark Prescott described his take on the sales process and some of the changes he has noted since his early involvement in the industry. He recalled how the first Horses in Training sale he attended had only 186 horses. In those early days, his role was to sneak around the sales ground stables late at night on the lookout for crib biters. Back then, there was no option to return horses after sale, and as a result, trainers preferred to buy horses from studs they were familiar with—a policy Sir Mark still follows to this day. 

Sir Mark went on to explain that he believes strongly that the manner in which an animal is reared has a strong bearing on their ability to perform at a later date. Sir Mark also mentioned that horses can cope with many conformational faults nowadays that would have been deemed unacceptable in his early years. He attributed this to improvements in ground conditions, such as watering and all-weather surfaces. 

Mike Shepherd, MRCVS, of Rossdales Equine Practice in Newmarket had been tasked with describing and discussing the sales examination from a veterinary viewpoint and in particular attempting to define what vets are trying to achieve in this process.

Shepherd’s key message was that the physical exam is the cornerstone of any veterinary evaluation. A vet examining a horse on the sales ground is not a guarantee that the horse will never have an issue—there is no crystal ball. Owners and trainers should be aware there are several limitations of the vetting process, and it is helpful to think in terms of a “pre-bid inspection” rather than a “pre-purchase examination”. The horse is away from its home environment, and this puts a lot of stress on the animal. In most cases, pre-purchase exercise is not possible, so conditions that are only apparent when the horse is exercising and in training may go undetected. 

Time is a major challenge, with both vendors and prospective purchasers pushing for everything to be done as quickly as possible. A busy sales vet may have a long list of horses to examine, and information on each must be transferred to their client coherently and clearly—all before the horse is presented for sale. It can be challenging  to acquire a detailed veterinary history. Previous surgeries, medication and vices displayed by the animal ought to be reported, but in many cases the person with the horse is not in a position to accurately answer questions on longer-term history. 

At Sales, ultrasonography of the heart (echocardiography) can be used to estimate heart size.

Everyone involved—the vendor, the prospective purchaser, and the auction house—wants the process to go ahead. The horse to be bought/sold and the vet can be seen as a stumbling block. Prospective purchasers may want the horse to be examined clinically, its laryngeal function examined by endoscope, radiographs of the horse’s limbs either reviewed or taken, ultrasound examinations of their soft tissue structures and heart performed. The role of the vet is to help the purchaser evaluate all this information and make an evidence-based decision on whether to purchase the horse.

Examining vets can face conflicts of interest when examining horses that are under the ownership or care of one of their clients. Shepherd explained how Rossdales, and some other practices involved in sales work, have a protocol that an examining vet will not perform a vetting on a horse in the care of one of their own clients, and will disclose to the prospective purchaser if the vendor is a client of the practice. It is crucial to avoid working for both buyer and seller as a conflict of interest becomes unavoidable.

It is also essential that the vet understands exactly what the horse is expected to do following the sale.  Thoroughbred horses in flat racing have short timescale targets and, as a result, certain parts of the examination carry more weight than others. For example, the knees and fetlock joints are commonly implicated in lameness in flat racehorses; thus particular attention must be paid to these joints when examining yearlings. Soft tissue injuries are impactful in all young thoroughbreds, but there is a particular emphasis on tendon integrity in the National Hunt racehorse because career-threatening tendon injuries are particularly prevalent in these horses. When evaluating potential broodmares, good feet are very relevant, and overall conformation is particularly important if the aim is to breed to sell. 

Vetting horses for clients aiming to pin hook their purchases places different requirements on the examining vet. These horses need to be able to cope with the preparation required for another sale, and they must also stand up to the scrutiny of vets at a later sale. The horse’s walk and conformation rank high in the foal/ yearling stage but may be judged to be less significant if the horse breezes in a fast time at a breeze up sale.

It is also critical that purchasers recognise that many of the common veterinary issues encountered in training are not detectable at the Sales stage. For example, subchondral fetlock pain (bone bruising), which is common in a large subset of thoroughbreds in training, is not accurately practicable in young thoroughbred prior entering training. 

For assessing laryngeal function, there is often concern that this may be too subjective. Dr Justin Perkins, of the Royal Veterinary College, has shown good agreement on endoscopic grading between experienced vets. However, horses’ laryngeal scores vary significantly day to day, and more worrying in the sales setting, one horse examined several times on the same day can have different scope grades. The gold standard in assessing the horse laryngeal function is an overground exercising endoscopy. This is not feasible on sales grounds, and purchasers should be aware that the limited purpose of a resting laryngeal scope is to exclude specific serious hereditary conditions and not to rule out problems which are only evident during exercise. Dorsal displacement of the soft palate cannot be accurately predicted at rest. Similarly, exercise-induced pulmonary haemorrhage or bleeding can be career limiting, yet once again in the juvenile thoroughbred, there is no way to predict this condition before the horse enters training.

Some conditions can affect some individuals yet be of little consequence in others. An example is kissing spines (impinging spinous processes), and whilst it can be a clinical issue in some individuals, it is commonly encountered in normal horses and therefore is very easy to over-interpret its significance.  

The Hong Kong vetting process is considered the gold standard in terms of assessing and examining a racehorse in training. Shepherd highlighted that some new rules have recently been introduced. There are now guidelines on measuring tendons, and horses with a superficial digital flexor tendon cross-sectional area of greater than 1.6cm2 are not allowed to be imported into Hong Kong because of a potential increased risk of tendon injury.

The use of medication in horses at the sales ground and early in their life is currently an area of controversy. The concern is that there may be longer-term impact. Penalties associated with the use of anabolic steroids are well documented: the horse will be placed under a lifetime ban if these drugs have been used. The British Horseracing Authority will also place a lifetime ban on horses which have received bisphosphonates.  Potentially, these drugs may have been given without the knowledge of the vendor, therefore client education and sales conditions will have to be adapted unless a sensible compromise can be reached to prevent a high-profile embarrassment for the authorities.

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