THE ISLAND 22 EQUESTRIAN PARK

From Horsetalk.com

Recomend you read the full article here. Excerts below.

"It only takes 17 minutes of moderate intensity exercise in hot, humid weather to raise a horse's temperature to dangerous levels. That's three to 10 times faster than in humans. Horses feel the heat much worse than we do."

And the effects can be serious. If a horse's body temperature shoots up from the normal 37 to 38 C to 41 C, temperatures within working muscles may be as high as 43 C, a temperature at which proteins in muscle begin to denature (cook). Horses suffering excessive heat stress may experience hypotension, colic and renal failure.

Horses also rely to a significant extent on sweating to cool them off. They can sweat 15 to 20 litres per hour in cool, dry conditions and up to 30 litres per hour in hot, humid conditions, but only 25 to 30 per cent of the sweat produced is effective in cooling the horse by evaporation.

"Just giving the horse water will not rehydrate a dehydrated horse. When horses drink plain water, it dilutes their body fluids, and their bodies respond by trying to get rid of more water and more electrolytes."

"Many riders will train their horses in the mornings or evenings, when it's cool, then go to a competition held during the hottest part of the day. You need to get horses used to being ridden in the heat and allow them to develop the full spectrum of beneficial adaptations that come with heat acclimation."

"You can cool the horse two degrees in 10 minutes this way: pour on the water, scrape it off, pour on more, and just keep repeating it," says Lindinger. "The scraping part is important because otherwise the water will be trapped in the horse's hair and will quickly warm up. By scraping and pouring on fresh, cold water you keep the cooling process going."