TOO HOT TO Handle

Find out what to do if your horse has a fever.

- ANNA O'BRIEN, DVM

Normal adult equine body temperature runs higher than our human version of 98.6° Fahrenheit, although anything above 101.5° is considered a fever for horses. What do you do when your horse is running a temperature? Let's take a closer look, including possible causes and how you can help.

What causes a fever?

The medical term for fever is pyrexia (pyro from the Greek word for fire). A molecule that causes a fever is called a pyrogen.

Think of any warm-blooded animal's normal body temperature as a thermostat set by a part of the brain called the hypothalamus. A pyrogen changes this internal set-point within the brain and turns the dial up, resulting in a fever.

Pyrogens can come from both outside and inside the body. Some types of bacteria contain specific chemicals that will directly cause a fever. Other bacteria, viruses, and infectious organisms stimulate the body's immune system to produce pyrogens that travel through the bloodstream into the brain and tell the hypothalamus to turn up the heat.

Typically, a feverish horse will be lethargic and off-feed. He may have droopy ears and seclude himself from the herd or won't come to the fence or stall door for a treat. If severe enough, he may show signs of dehydration, such as an extended skin tent and/or dry and tacky gums.

Taking a horse's temperature

Ideally, you should train your horse to accept having his temperature taken before he gets sick. Temperatures should be taken rectally on horses; temporal thermometers designed for use on your forehead will not work through a horse's hair coat.