Cooling Overheated Horses

Photo: Anne M. Eberhardt/The Horse

Q:With summer upon us, I am concerned about exercising my horse in hot weather. What can I do to make sure my horse is properly cooled out? Are there steps I can take before, during, and after exercise?

A:There are many variables involved in this question. The answer depends on how much exercise your horse will undertake and how strenuous the exercise is. Also, it is necessary to consider how hot the external temperature is. Other considerations include how fit the horse is and how the horse is going to be used. Is he going to be asked to do work beyond what he normally does?

There are some basic things you can do to make sure that your horse does not overheat during the summer. Your horse should be fit. If your horse is in good condition and if you have been exercising him on a regular basis as spring has progressed into summer and the temperatures have steadily risen, then you probably have been preparing him for summer exercise. This type of regimen should have acclimated him to the heat and to the type of environment in which he must work.

The best way to make sure that your horse is not being placed under too much heat stress is to take his temperature. You should know what your horse's normal temperature is. By taking his temperature before and after exercising him, you will be able to discern how much "heat load" he has accumulated during exercise. For example, your horse's temperature after exercise is normally about 103° Fahrenheit. A reading taken before exercise was normal (less than 101°). You go on a fairly long ride on a hot day. Afterwards, when you check his temperature again, you find his reading to be 105°. You should get him out of the heat, put him in the shade, and make sure he cools out well. You need to give him a bath. Hose him down with cool water. Using a scraper, remove the excess water from his body. Then hose him down again. Retake his temperature and continue bathing him until his temperature is less than 101°. These steps allow him to cool efficiently.

There are occasions when you might not have a thermometer tucked safely away in the pocket of your riding pants; therefore, you need to be aware of some of the warning signs that indicate heat stress. If your horse seems distressed, tired, or unwilling to go on while exercising in the heat, these can be an indication of heat stress. Other telltale signs include lethargy, blowing hard, standing without showing any interest in what's going on around him, and not exhibiting any interest in grazing. Should your horse display these signs, then you should stop exercise, get him in the shade, and begin cooling him out. Consult a veterinarian if your horse does not cool out within one hour.

You asked if there were any steps you could take before, during, and after exercise to insure that your horse will be properly cool. First and foremost you can get him fit. If you know the kind of competition in which your horse will be performing, then you can train him for that event. The proper training regimen will provide the fitness he needs to endure the rigors of the event. 

You also can get him acclimated to his environment. If he is to compete in another part of the country where the environment is substantially different from where you normally live, you might want to consider taking him there ahead of time and training him in that environment so that he will be more acclimated than if you just ship in the day before the event or ship in the day of the event.

Remember, too, that shipping is hard on a horse. When you have to ship a horse long distances, you start out behind the eight ball. You need to make sure that your horse is well hydrated prior to shipping and that you arrive at your destination in enough time for him to replenish the fluids that he lost during transport. You might want to give him balanced electrolytes, both before and after shipping, and make sure that a source of salt is readily available.

The advisability of giving your horse fluids during exercise depends on the type of exercise in which he is involved. If he is doing an event like an endurance ride, you might want to provide electrolytes for him. During the ride you can allow him to drink as often as possible as you go along. If your horse is performing short, intense exercise, such as racing or three-day eventing, administration of concentrated electrolyte solutions during exercise is not helpful as the horse will have no opportunity to drink during exercise; however, provisions of adequate electrolyte supplements before and after exercise are advisable. Consult your veterinarian for specific recommendations.

After the competition, you want to make sure that your horse has shade and a bath with cold water. Be sure to look for any signs of stress, including a high heart rate.

As with human athletes, fitness is the key to a successful performance. Making sure your horse is in shape to do what he is asked to do, making sure that he is acclimated to the environment in which he is asked to perform, and making sure that he is properly hydrated before his event are three basic building blocks for a safe and successful performance.

About the Author

Catherine Kohn, VMD

Catherine Kohn, VMD, currently at The Ohio State University College of Veterinary Medicine, serves as United States Equestrian Team veterinarian and was the FEI veterinary delegate at the U.S. Olympics in 1996 and at Rolex Kentucky in 1998.

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