Riding In The Heat

RIDING IN THE HEAT. Some information if you are considering riding in very hot and or humid conditions. Who is more likely to overheat – you or your horse? It might surprise you to know that your horse gets hotter, much faster than you and is more susceptible to the negative effects of heat stress. “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 are more susceptible to heat for several reasons. First, they are larger and have a higher percentage of active muscle than people do during exercise. When muscles are being used, they produce a lot of heat. 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 25-30% of the sweat produced is effective in cooling the horse by evaporation. “Because so much more sweat is produced than can be evaporated, the rest just drips off the horse’s body,” “By comparison, up to 50% of the sweat people produce is evaporated from our bodies during exercise and helps to cool us.” The salts in horse sweat are also four times as concentrated as in human sweat. “Those salts have to be replaced,” he adds. “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.” Horses also pant to dissipate heat, but this is only effective if the air is at least five degrees cooler than the horse’s body temperature. FOOD FOR THOUGHT WHEN CONSIDERING RIDING IN THE HEAT. Some exerts from: Michael Lindinger, PhD, MSc, an animal and exercise physiologist at the University of Guelph