By Danielle Pleasant

Warm summer days have many equine enthusiasts ready to saddle up and ride, however with the rising temperatures, we must be cautious of overheating our equine partners. Being aware of our horse’s physiology, as well as, knowing the signs and symptoms of dehydration and heat related illnesses can help us provide the best care for our animals during sweltering summer days.

Horses release excess body heat by sweating. As the sweat evaporates, it causes a cooling effect. High humidity, along with high temperatures, compromise this effect, reducing the horse’s ability to efficiently cool down. A good rule of thumb is if the combined air temperature and humidity are over 150 care should be taken to ensure the horse does not become heat stressed.

As horses sweat, water and electrolytes are lost. The average horse typically consumes 6-10 gallons of water daily. Factors such as diet, exercise and temperature can greatly influence water intake, increasing the maintenance level anywhere from 20-300 percent. Meaning a horse may drink 20 or more gallons of water during hot, humid weather. Providing clean, fresh, cool water along with salt will help avoid dehydration. If electrolytes or flavorings are used, be sure to offer plain water as well (Ivey).

Take advantage of cooler temperatures in the early morning, late evening and even overnight for turn out times. Sunscreen, masks, and flysheets may be beneficial for horses prone to sunburn. It is best to avoid riding or exercising during the hottest part of the day. However, if your horse must be worked (perhaps for a show or competition) help keep them cool between classes and after excising by taking advantage of shady and natural breezes, utilizing fans and misters, and sponging or hosing them off. Be aware that water can be insulating and if not scrapped off, negatively affecting the horse’s ability to cool down (Porr).

When stalling your horse, keep the barn as open as possible and use fans if necessary to keep good ventilation; just be sure to keep electrical cords and plugs out of the horse’s reach. Pasture kept horses also need shade, run-in sheds and trees are sufficient. Be aware that shaded areas may change throughout the day as the sun moves, so have a plan to provide sun relief throughout the day (Johnston).

Body condition and feed management also affect a horse’s ability to stay cool. The additional body fat in an overweight horse acts as insulation, trapping body heat, making cooling down more difficult. Furthermore, the digestion of feed generates body heat, with some grains and forages producing more heat than others. This can be a problem, particularly for thin horses, if a horse goes off feed when too hot. Adding fat to the daily ration(s) will increase calorie intake without increasing the volume of the feed. Fat also produces less heat when digested compared to protein and carbohydrates. Additionally, feeding grass, instead of legume, forages will also decrease metabolic heat (Porr).

Knowing your horse, as well as the dangers of prolonged exposed to high temperatures are vital to maintaining your animal’s health and avoiding costly treatment. Overheating, due to hot weather, excising, standing in a hot stall or trailering can result in dehydration, muscle spasms, colic, heat stress and even heat stroke.

Profuse sweating or lack of sweat, lethargy, dry mucus membranes, prolonged skin tents (4-10 seconds), increased heart rate, incoordination and rectal temperatures above 103° are common signs of heat related illness. If you suspect your horse is suffering from a heat-related illness, move your horse to a cooler environment and contact your veterinarian immediately. Prevention is much easier and less detrimental to your horse and wallet, so before saddling up, think about how you are going to keep your horse cool (UMN Extension).