The record heat of the summer of 2012, to say nothing of the prospect of more to come in this era of climate change, brings to the forefront the question of the sweating horse and what it means to a wagering decision. Is the horse sweating because of the heat, because he’s sick, or because he has something on his mind? Here are some ideas to help you make a decision about the importance of sweat.
Sometimes it really is just hot weather. Horses evolved into the modern species in the Steppes of Asia and were probably first domesticated in the mountains of northern Kazakhstan. While the great Steppe is hot in summer, it can be extraordinarily cold in winter. Today, 6,000 years after domestication, horses not only survive very cold weather but most prefer cold weather to hot. To be fair, more recent ancestors of our racing breeds spent many generations in the Arabian and North African deserts, but it was their cross-breeding with horses from the colder north that produced the Thoroughbred and then the Standardbred racehorse.
Evolution gave horses, like people and unlike many other species, the ability to sweat to cool their bodies in the heat, and many of them take full advantage of the facility. On a hot day, a horse should sweat and a moderately wet animal is not likely to be inferior to the other horses in the field. However, if he seems seriously distressed by the heat he may have a problem that will play out in his racetrack performance. He shouldn’t have dramatically more sweat than the others in the field, his flanks shouldn’t be heaving with too-rapid breathing, and his nostrils shouldn’t be flaring dramatically. All are signs of heat distress. A rapid heartbeat is another warning sign, but you’re not likely to be aware of it. In most cases, the horse’s trainer will have already noticed signs of impending heat distress and you won’t be presented with the problem of betting on the horse. But in a few cases, you may need to pay attention to those warning signs.
Lack of sweat can also be a problem. Some horses are anhydrotic, which means that they don’t have the ability to sweat at all, thereby losing the capacity to cool themselves off through evaporation. An anhydrotic horse should not be racing on a hot day, probably shouldn’t be living in a hot climate, and should not be bet on if the temperature is high because he’ll be a likely candidate for heat-related disaster. If the day is hot and you see a horse without the slightest trace of dampness he may be anhydrotic and that’s not good. On a cool day you’re not likely to recognize that he’s anhydrotic and he most likely will have no problems anyway.
When a horse is sweating on a day that’s not particularly hot you have a greater challenge. Profuse sweating is a symptom of both severe pain and serious illness, but you are unlikely to see a horse with either problem in a post parade. You are more likely to see a horse suffering from one of the other causes of excessive equine sweat: fear, anger, agitation, nervousness. Whether any of these attitudes is likely to impact negatively on a horse’s performance depends on its intensity and how the horse behaves as a result of it. Many horses race best when they are a little nervous and some thrive on anger. Few perform well when fear overtakes them. If the emotions are intense you are likely to see signs in addition to sweating. Think carefully before betting on a sweaty horse with one or more of the other indicators: swishing or pinned tail, ears pinned back, white visible in the eyes.
Finally, you are going to have to consider kidney sweat. This is the thick white substance that often shows up between the hind legs. Some experts believe that kidney sweat is actually different from clear sweat, containing protein in addition to sodium and potassium, indicating greater kidney involvement. Others think that kidney sweat looks different because of the damp and dark location. Many handicappers automatically reject a horse showing any kidney sweat at all, while others are a little more flexible. A modest amount of kidney sweat between the hind legs is acceptable, but a foaming, dripping white substance there or elsewhere is not. White sweat on the back or neck rarely bodes well for your bet.
But always remember that horses are individuals. Some horses sweat more than others, even in situations where the weather is cool, they’re not nervous, and they feel just fine. If you have chosen to reject a sweaty horse that turns out to be a winner, remember it for the next time that horse shows up to race.