As summer temperatures continue to rise, make sure you are carefully monitoring your horse’s health. Horses can produce a significant amount of heat through digestion of feed and exercise. Heat production can increase up to 50 percent during exercise compared to a horse at rest. If the outside temperature is warmer than the horse’s body temperature, sweating becomes the main means for a horse to cool itself because blood shunting is not enough. A horse’s body reacts to high temperatures by shunting blood towards the skin surfaces to dissipate heat. However, when there is hot and humid weather, sweat produced cannot evaporate and the horse’s body cannot properly cool itself. As the amount of sweat increases, so does the imbalance of body fluids and electrolytes. This can lead to heat stress.
Heat stress can lead to increased sweating, muscle weakness, rapid breathing, and unusually high temperatures. Preventative measures should be in place any time the temperatures begin to rise. If exercise is necessary, make sure it occurs at a time when it is cooler such as early morning or late evening. After working your horse, cool it down slowly. Make sure to offer sips of cool water to the horse to prevent dehydration and walk the horse. If horses are permitted to stand for a prolonged period of time immediately following strenuous exercise, their muscles can stiffen and will not dissipate heat efficiently. Try to feed your horse 3-4 hours before exercise whenever possible because chewing and digesting feedstuffs can generate a large amount of body heat. If you suspect water loss in your horse, you can use the pinch test. When you pinch the skin on the neck or shoulder, the skin should quickly recoil, if not, your horse is most likely dehydrated.
Left untreated, heat exhaustion can rapidly proceed to heat stroke. Horses with heat stroke exhibit hyperthermia and nervous system dysfunction. Signs of heat stroke include weaving when moving, rearing, falling, unable to rise quickly, seizures, coma, and worst case, death. These horses become unaware of their surroundings and their skin becomes dry and warm. Complications such as laminitis, kidney or liver failure, colic, or respiratory issues are known to be in response to heat stroke.
Knowing these warning signs and prevention methods can help them avoid heat stress. And remember, you can always contact your veterinarian for advice or help if you need it.