The first thing to do for a horse with “heat exhaustion” is get it into the shade. Stop all physical activity, and if it was being ridden at the time, take off all the tack.
Hose the horse down with cool water, concentrating on the legs and neck (where the big jugular veins run) and the back. Then either scrape off the excess water and hose again or put the horse in front of a good, high-powered fan or several fans for better cooling. An overheated horse can heat up the water sitting on its skin, which literally insulates the heat against its body!
For a severly high fever (rectal temperature over 104.5 degrees F), towels soaked in ice water can be repeatedly applied to the horse’s back and neck, or ice water can be sponged onto the horse. Rubbing alcohol can be poured down the horse’s back for evaporative cooling, or it can be added to your ice water mixture. Be careful not to get the alcohol in the horse’s eyes or any open wounds.
Often times these horses are dehydrated as well, so offer the horse a fresh bucket of water, preferrably tepid or cool, but not ice cold. Water with electrolytes is okay, but make sure there is a source of plain water availabe, too. It’s a good idea to keep a salt block near the water source or add a small amount of salt to the feed. Have water in several locations so that horses do not have to travel a long way or compete for it.
Sometimes a horse with heat exhaustion still needs veterinary care, as a prolonged high temperature or severe dehydration can cause organ damage. An examination and bloodwork is usually required to determine the extent of such damage and the treatment necessary.
Anhidrosis (poor sweating or not sweating at all) can lead to heat exhaustion. Please see our “links page” for a web article on anhidrosis.