It’s the middle of summer and much of the country is going through extreme heat and humidity. Horses can get heatstroke just like humans.
Here is some important information about summer riding and signs of heatstroke in horses.
Summer riding reminder
The Heat Index is the sum of the temperature plus the humidity.
For example: If the temperature is 80 degrees Fahrenheit and the humidity is 20%, then the Heat Index is 100 (80+20=100).
If the Heat Index is less than 120, it is ok to ride. Start watching it as it rises above 120, at 150 your horse’s cooling system won’t work effectively. If it is greater than 180, your horse will be unable to thermo-regulate.
When is it too hot to safely ride my horse?
Written by: Sallie S. Hyman VMD, DACVIM, CVA
Knowing how your horse thermo-regulates will help you better understand how to keep him cool. A horse’s body produces heat when he works. Horses have several mechanisms that get rid of this heat.
The most important mechanism is evaporation. Most heat is generated from a horse’s large muscle mass. The cardiovascular system (the heart and blood vessels) move the heat from the muscles and organs to the skin. As your horse works, he produces sweat in glands in his skin. This sweat is composed of water and electrolytes (sodium, chloride, potassium, and calcium). As the sweat evaporates, it dissipates large amounts of heat, thus cooling your horse. To give you an idea of how much a horse needs to sweat to keep cool, the amount of heat dissipated by one liter of sweat equals just one to two minutes of maximal exercise, or five to six minutes of sub maximal exercise!
Signs of Heatstroke in Your Horse:
•A Respiratory Rate Higher than 30, that does not return to normal after several minutes of cooling off
•A Heart Rate Higher than 80, that does not return to normal after several minutes of cooling off
•Excessive sweating, or ceasing to sweat at all
•Temperature of more than 103° F, that does not decrease after several minutes of cooling
•“Thumps” – diaphragmatic flutter due to calcium loss. You will see this as twitching of the stomach area.
If you see ANY of these problems, cool your horse with plenty of cold water, allow him to drink if he wants, and call your veterinarian! You can give paste electrolytes orally as well, such as Neogen Stress-Dex Gel or Summer Games Electrolyte Paste. Your veterinarian will decide if IV fluids and electrolytes are needed.
Horses who do experience heatstroke should be rested for ten days and given a few days of light work before being brought back to normal work. Keep in mind that horses that experience overheating are more prone to do so again, so best to prevent it in the first place!