Stabling and health specifically for racehorses

In looking at this subject, it is important to see the needs of the racehorse as being different from horses kept for any other sporting purpose. Its management, feeding, training and stabling are all critical and unique. For racing, all body organs must function efficiently and, in so much as these can be affected by stabling conditions, it might pay to take a critical look at the elements involved. Our discussion is particularly about the way stabling and stable management influence lowgrade or ‘sub-clinical’ disease. It is not about major diseases like flu or strangles, although aspects of stabling can affect the degree of illness as well as recovery times in these conditions too.

VARYING NEEDS Stabling standards differ from country to country and from season to season. Horses racing in a UK winter, for example, face more climatic fluctuations than in summer or than others might in warmer places, like Dubai, or Florida. Yet the principles of management are similar for all. The horse’s needs vary with prevailing conditions and change has to be recognised and accounted for. To limit infection, it is necessary to understand how organisms set up disease as well as how horses resist infection. In my lifetime, there has been a seachange in stabling ideas generally and it is appropriate to ask why and with what degree of logic. 1 An increased racehorse population from the Sixties onwards meant bigger yards, a movement towards barn-type buildings on economic grounds. The importance (and difficulty) of controlling temperatures and airflows was overlooked until problems arose and these were reflected in results on the track. 2 Condensation in old damp buildings, where water ran from walls and ceilings, was resolved by radically increasing ventilation. This reduced dampness – but the negative consequences brought an increase in lowgrade infection. 3 Vets treating horses with severe respiratory disease, like COPD, saw a need for more air. Bigger holes were made in stable walls, even between individual stables. No one asked if the fit racehorse, not being ill, might be unique in not tolerating this.

DEFENCE AGAINST THE ENVIRONMENT It is essential to the health of racehorses that their stables are clean, warm and draft-free. The defences against infection operate best when environmental conditions are stable and unchanging, when there is warmth to maintain body temperature without a need to burn-off stored energy to combat the cold. Consider that the stabled horse cannot generate heat from movement and cannot remove itself from unhealthy or unpleasant conditions. In fact, with certain variations, the horse’s resistance to infection runs very close to that of humans in similar conditions. Having a thick skin and hairy coat does not prevent disease; besides, we are obliged to clip coats, automatically reducing the insulating influences of fat through the training programme. Furthermore, warm clothing cannot compensate for drafty airflows and a cold horse loses weight as well as the fuel it needs for work. It also loses some of its ability to resist infection at a cellular level. Add to this how intensive training affects fluid balance and demands fine tuning of all body systems, and disease at even a sub-clinical level is easier to understand.

RESISTANCE Natural resistance in otherwise healthy horses decides the length of time from infection to recovery and this, with most known organisms, is never open-ended. Resistance is, in fact, a measure of normal health that can be lost through disease, malnutrition or age. While recovery from debilitating conditions may be slow, sub-clinical infections should be overcome in days rather than weeks. Where this is not the case, external influences are likely to be involved. Stabling factors are a common cause. In recent times, all sorts of ‘medicines’ have been used to bolster resistance, but with little effect – because the answer frequently lies in the stable, not the horse.

ANECDOTAL EVIDENCE In horse management generally, many ideas and accepted facts are anecdotal and always have been. That is, they have come by word of mouth, from the trial and error investigations of individuals rather than through scientific research. Racing history suggests our ancestors knew as much about the horse as we do today, that despite talk of new levels of fitness, modern training methods are superior to those of the past. Many old ideas came from people who relied on their horses for work, transport and enjoyment. They were never backed by science because it was never possible to do so. But poor science, based on assumption, is no better than anecdote and there has been much of that. Technology hasn’t helped either and we should never dismiss knowledge as ‘unscientific’ unless there is solid evidence against it. For example, some today keep their horses in Arctic-cold conditions while others speak of heating stables. Both cannot be right.

SUB-CLINICAL DISEASE The term ‘sub-clinical’ describes any disease condition where the symptoms are obscure, whatever the cause. In the main, it refers to viral and bacterial conditions where the affected animal is not obviously ill, but racing performance suffers. The organism, when isolated, might not be thought capable of causing disease. That it becomes so is a reflection of stress, something in the horse’s management that favours infection. There have been numerous examples in modern times. One reason acceptable research is lacking is because medicine has no fool-proof way of identifying sub-clinical infections, especially when the final measure is the racecourse. A negative laboratory finding is worthless if the horse runs badly and, in fact, no research into performance-related problems can ever be fruitful if lowgrade conditions are not accounted for. In the absence of science, of course, anecdotal evidence is all there is. But, to be acceptable, it must come from informed sources, from volume experience and the studied observation of people educated to see and know. It won’t come from those who interpret tests and machines, or from the experiences of those in non-racing areas.

DECISIONS ON BUILDING Stables are often built with cost a first priority, even with the comfort of humans put before horses. Then, when disease appears, questions are raised about whether or not building design might be a cause. Opinions have often been provided by individuals with no understanding of the elements involved. ‘Experts’ emerged from areas like pig management, which was novel. The needs of sedentary animals reared to produce fat are not the same as those in whom fat is distinctly unwanted. Ultimately, disease has to be dealt with by professionals. Any infection needs to be investigated to provide understanding and control. In an ideal world, organisms are isolated and identified. But, as we know, unexplained outbreaks – loosely described as ‘the virus’ - have ruined the careers of both horses and trainers. Their true cause might never have been defined, but a list of the victims contains some distinguished names as well as many who never got off the ground.

‘THE VIRUS’ In relating health and stabling then, we are addressing a problem that has plagued UK racing for years. Inevitably, busy yards are exposed to organisms that arrive from different sources and can cause disease at any time, sometimes leading to outbreaks that last long periods, belying accepted patterns. Mixed or sequential infections are a feature of this and one organism may simply follow another, or become re-activated, as appears to happen in herpes infections. Actually, the term ‘the virus’ means nothing specific. It can represent infection by a single virus, but more commonly reflects a lowering of resistance that gives opportunity to any organism going the rounds. The distinction between debilitating conditions and ‘the virus’ lies in the clinical effect. In a serious infection, a horse is sick and evidently so. With ‘the virus’, animals look healthy but are unable to show their form. A range of mild symptoms may be seen, but observers comment on how insignificant they are. Most eat and drink normally, look ‘big’ and well; others have dry coats, lose condition and seem to lack energy. The general view is that they are not sick, as trainers regularly insist. Some, that appear to work well, are only found wanting when raced. Looked at more closely, the lining membranes may be inflamed, lymph glands enlarged, there may be watery, or thicker, discharges from nose and eye. However mild, these are signs of disease. Lowgrade liver involvement may occur and is a serious impediment to racing. The horse will not return to form for months rather than weeks. Bleeding from the lungs is also more common in the presence of infection. It is likely to become chronic where the aggravating factors are not removed.

MEASURING FITNESS As a practising vet, I cut my diagnostic teeth on viral outbreaks that initially involved stud farms, then moved to racing with a view to defining the parameters of infection and monitoring horses as they returned from illness to full training. The task was to relate this to form on the course and, ultimately, to see if it was possible to diagnose with certainty and predict with any degree of accuracy. To do this, it was necessary to find a simple way of measuring health in a fully fit horse and to pit this against expectation, or effort on the track. An effective method had to give instant information, prove reliable and be consistent. It, ideally, needed to be effective the day before a race and would prove worthless if not accurate to a high degree. It was necessary, too, to recognise that a horse with no identifiable infection might have other physical problems, be unwilling or temperamental. So the exercise was complex and movement, for a racing animal, is as important as heart-beat or lung expansion. THE HEART An idea came after Roberto, an Irish Derby favourite trained by M. V. O’Brien, ran down the field; and the belief that such a performance had to be predictable through the heart’s action, which it would have been. While the technique doesn’t have a wide use, because of the complexity of issues and the difficulties of interpretation, it has proved extremely useful in evaluating management factors that influence health and stabling. The heart of a healthy racing animal is obliged to operate with ease and strength during work, the ability for which is best judged when at rest in the stable, preferably some hours after exercise. As training progresses, it adapts to its greater workload and strengthens; the resting beat-per-minute (bpm) rate also reduces. The sounds in a healthy horse are consistent and reliable, although there are many normal variations as well as changes that verge towards the clinical. They can, with experience, be interpreted to provide a reliable measure of health in a fit horse. There is a whole range of factors that might influence heart sounds, not just illness or infection, and the predictability of peformance relies as much on precisely how fit an animal is as on its state of health. The task of evaluating sounds is complex, too, and the variety of changes from normality is extensive. Any imposition on the heart’s working capacity (by infection, dehydration, anaemia) brings changes that are recognisable with a stethoscope, therefore open to interpretation; they can be related to performance capacity once all necessary information is included in the opinion. The extremes of heart function are heard in serious clinical infection (when the beat is usually loud and the bpm elevated) and with the least intrusive organisms (when changes are more subtle). The likely influence on peformance is often a fine judgment, especially so where infection is slight and the horse is overcoming it.

RESEARCH All this, of course, is subjective, therefore unlikely to satisfy scientists, but it works in the field and makes it possible to understand and differentiate between causes in a way that other systems cannot. Infection is probably the most common cause of performance disappointment. By using this kind of monitoring, it is possible to move affected animals from one stable to another and evaluate how they react and how quickly infection is overcome, the racecourse being a critical test of the decisions made. Thousands of horses in a variety of management conditions have provided private research facilities with material and are the basis of the opinions expressed here. Many horses were monitored on a daily basis, even through the course of a racing season. There are, sadly, no records, but the opinions have come from many years of working with both Flat and National Hunt animals, in yards that varied in size from a handful to a hundred-plus. As a general rule, no attempt was made to isolate organisms – mainly because of past problems with isolation and interpretation. At times, organisms were isolated which, on all the evidence, looked responsible for disease yet were considered at laboratory level to be insignificant. While this situation may have changed, the necessity clinically is to assess the situation and act; there is no time for delay. In most of my work, the diagnosis of infection was based purely on symptoms. Old and new yards were involved, old and young horses, old and modern buildings, barns as well as single-stable units. It proved possible to relate performance to specific conditions and origins. Once the complexity of the exercise was overcome, it was simple to assess infection and follow it through its course from start to return of full performance expression.

Distinguishing between the responses of horses kept in different stabling and environmental conditions became routine. Even in infected yards, some were kept racing while others about them were ill, as long as the management elements were understood and permitted it. The very successful jumps trainer Fulke Walwyn achieved great success at a time when very different attitudes pertained to today. Known as ‘a windows man’, it was common for him to be seen adjusting windows in an effort to control airflows as conditions and temperatures changed. His horses ran with great consistency, as did those of Tom Dreaper, who appears to have held similar principles, judged by pictures of Arkle in his stable. Perhaps both knew from instinct things we overlook now, or they may simply have followed the advice of their forebears without giving it too much thought. Finally, it needs to be stressed that this exercise was conducted on fundamentally healthy horses, to interpret and control performance on the track. For it to work, management generally has to be of the highest standard and that applies to everything that surrounds the life of a racing animal