Overheating: Dangerous!

Disclaimer: The following is only general information. If you believe that your horse has a problem please call your veterinarian as soon as possible.

If you are riding and you get really hot, then your horse gets even hotter. In fact a horse’s body will heat faster than a human’s and is less able to cope with the increase in body temperature.

2 650 Cross-Country

Dr. Michael Lindinger, an animal and exercise physiologist from the University of Guelph, explains that “It only takes 17 minutes of moderate intensity exercise in hot, humid weather to raise a horse’s temperature to dangerous levels. That’s 3 to 10 times faster than in humans. Horses feel the heat much worse than we do”.

If a horse’s temperature shoots up to 41°C then the temperature within its working muscles may be 43°C. At that temperature, the proteins in the horse’s muscle start to cook, which can lead to high blood pressure, colic and kidney failure.

The main reasons for this difference between humans and horses are:

Horses are larger and have more active muscle during exercise, which produces more heat

Horses can sweat 15 to 20 litres per hour in cool, dry condition and up to 30 litres per hour in hot, humid conditions.

Horses can only use about 25% to 30% of this sweat to cool themselves.

Humans can use up to 50% of their sweat to cool themselves.

The salt in horse sweat is four time more concentrated than in humans so they loose electrolytes faster and dehydrate quicker.

His tips for protecting horses from the harmful effects of overheating and dehydration are:

Teach your horse to drink an electrolyte solution, which is water with the right amount of salts dissolved in it – follow the manufactures instructions or veterinary advice. It can take a while for the horse to get used to this drink, so teach the horse before you really need it. Keeping your horse hydrated is the most important thing you can do to protect against heat stress. Plain water will not rehydrate a horse quickly and concentrated salts (such as pastes), without the horse drinking enough water at the same time, could make matters worse.

Acclimatise your horse to the hot conditions before you get to the event. To do this your horse will need to spend 4 hours per day at least 5 days per week outside during the hottest part of the day. This should be done for at least 3 weeks before the event. For the best results, exercise the horse for an hour during the second hour of his heat exposure. Most riders choose early morning or late afternoon when it is cooler, unfortunately this may not prepare the horse for competition or an activity which is held at the hottest time of the day.

When you are at the event look for shade and breezes to cool down.

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Never use a blanket or ‘cooler’ on a horse that is sweating.

The best way to cool a horse is to wet their body and scrape off, wet the body again and scrape off. Continue to do this and you can reduce a horses temperature by 2° in 10 minutes. You need to scrape the excess water off the horse otherwise it heats up and stops the cooling process.


Lastly, make sure that you pack all the necessary equipment you will need to cool your horse and keep him hydrated


The above information is only general in nature. If you believe that your horse has a problem, please call your veterinarian as soon as possible.