When horses overheat, they can quickly become dehydrated, weak, and uncoordinated, and in severe cases they may collapse or suffer heat stroke. Signs include heavy breathing, a very fast pulse, profuse sweating or, sometimes, no sweating at all, plus lethargy and stumbling.

What it looks like

A horse that is overheating may start breathing hard, stop performing normally, and seem dull or shaky. More serious cases can show a very high body temperature, dark urine, dry skin, or even convulsions or coma.

Why it happens

Heat buildup is more likely during hot, humid weather, intense exercise, poor ventilation, transport, or if the horse is overweight, unfit, very young, old, or ill. Horses cool themselves mainly by sweating and by moving heat out through the skin and blood flow, so anything that disrupts those systems raises risk.

What to do

Move the horse to shade or a well-ventilated area, stop exercise, and cool the body with cold water, especially over large blood vessels. Offer small amounts of water, and get veterinary help quickly if the horse is weak, not recovering, or showing severe signs.

Prevention

The best protection is to avoid hard work in extreme heat, provide shade and airflow, monitor hydration, and watch humidity as well as temperature. Horses that are not sweating normally need extra caution because they can overheat much faster.

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