Taking a Horse’s Temperature

With today’s digital thermometers, it’s easier and faster to take a horse’s temperature than in days gone by. Years ago, rectal thermometers designed for horses had a small ring at one end to which owners tied a long piece of string with a clip on the end. The thermometer could be inserted into the horse’s rectum and the string clipped to the tail hairs. This measure prevented a disconcerting disappearance of the entire thermometer deep inside the rectal tissues of the horse. Older thermometers had to stay in place for several minutes, taxing the patience of horse and handler. Digital thermometers allow the handler to get a reading much more quickly.

To take a horse’s temperature, first tie the horse or have someone hold his head. Stand beside (not in back of) the left hind leg, lift the tail slightly to the side with your left hand, and insert the tip of the thermometer a couple of inches into the rectum with your right hand. Generally, you don’t need to use any sort of lubricant, and most horses don’t object to the procedure. It’s still wise to keep a tight grip on the thermometer! When the temperature has stabilized, remove the thermometer and read the result.

It’s a good idea to take your horse’s temperature a few times just to practice and to get a baseline of what his normal temperature is. In general, temperatures are a little lower in the morning and a little higher in the evening or after strenuous exercise. A reading of less than or equal to 101.5^o F (38.6^o C) for a mature horse or up to 102^o F (38.9^o C) for a foal is considered normal. Higher readings may indicate infection or other illness. If a reading is higher than normal, consult a veterinarian.