Heat and exercise can lead to serious problems with overheating. Most people know a horse should be cooled out after exercise, but there’s a lot of misinformation and missing information on how it should be done. Follow these guidelines for effective cool-downs:

Always walk for the last 10 to 15 minutes of your ride.

Let the horse drink as much as he wants after removing your tack.

When he’s finished drinking, hose him with running cool water, or sponge liberal amounts of water over his entire body until the water running off is no longer hot.

Scrape off excess water and start hand-walking the horse in a cool, shaded area.

Do not put a sheet or cooler on the horse.

Check the skin often during walking to make sure the horse is cooling down and not sweating again. If he begins to heat up or sweat, repeat hosing or sponging.

With very high heat, especially if it’s humid, consider setting up a few fans in the area where you walk your horse. Misting fans are used to help avoid heat-related problems in horses at the summer Olympics.

Offer additional drinking water at frequent intervals.

When the horse’s skin has cooled down to feeling normal, or his rectal temperature is no higher than 101, you can safely put him away.

When to feed is another common question. It’s OK to let your horse grab some grass while you’re walking him to cool down (grass is about 80% water anyway), and after he has cooled down. It’s also OK to let him have hay after his cool-down is completed. Best to wait at least an hour after stopping exercise to feed any grain, though.

Some Common Myths

1. Hosing a horse with cold water will cause muscle spasms or a heart attack.
Completely false. Cold water won’t hurt the horse one bit, and the cooler the water, the more efficiently it will cool him down.

2. Letting a horse drink all he wants after exercise will cause founder (or colic
Again, completely false. Water cannot make a horse founder, no matter how much he drinks, or when. (An important exception to this is the horse that is severely overheated. See sidebar “Heat Can Kill.”)

3. Cold water will cause founder or colic.
It won’t. But studies have shown that horses given warmish water will drink more. So it’s a good idea to draw a bucket of water and let it warm up a bit if your water supply is very cold.

4. Horses cool out faster when wearing a cooler.
Nonsense. Never put any kind of cooler on a horse in hot weather. When you’re hot, do you crawl under a blanket or take off extra clothes? The same thing goes for your horse. You want his body heat to transfer to the air and blow away, not be trapped close to him.

5. Never clip a horse because his hair helps him cool out quicker.
Like #4, this is also false. Common sense alone will tell you that the less you have between skin and air, the quicker cooling will occur.

Keep Cool with Salt
Hans is a German Warmblood competing in combined training. He’s a very talented horse, but his progress through the ranks was limited by a problem with overheating and panting. He also didn’t drink well when away from home. A review of his diet showed his salt intake probably wasn’t high enough. When his owner started adding salt directly to his meals, the panting and overheating disappeared. He also drinks well now, wherever he goes.

Heat Can Kill
Horses overworked in the heat can develop body temperatures of 105º or higher and risk damage to their brain, muscles and internal organs — even death. Overheating is possible any time the temperature and humidity combined are more than 150 (e.g., 80º temperature and 70% humidity, 100º  temperature and 50% humidity, etc.), so use caution in those instances. When you add “normal” summer temperature and humidity percentage, they often total at least 150. You may be tempted to ignore this advice, thinking that you’ve frequently worked your horse hard when the total is over 150. But veterinarians tells us that they see a fair number of horses collapsing from the heat every summer, or at least having low-level heat exhaustion.

Over 150, don’t push your horse, keep your rides slow and easy, and be sure you both have frequent access to water. Overheating is a very strong danger when the combined numbers are more than 180, so extreme caution is needed then and, in fact, you probably shouldn’t ride in those cases.

Dark horses overheat quicker than lighter colored ones, and horses that are not fit also overheat much quicker. Heavy sweating, or heavy sweating followed by a drop in sweat production, fatigue, stumbling and rapid breathing are all warning signs. Also, heat-related problems are especially likely when the heat is a sudden weather change, where the horse has not yet had a chance to adapt.

If you think your horse is overheating, stop work immediately, remove all tack, get him out of the sun, offer water (about a gallon at a time, at five-minute intervals) and run water over the horse constantly. If his body temperature does not drop back to a normal of 100 or 101 rapidly within the first few minutes, call your vet immediately. Heat exhaustion/stroke is a medical emergency.