Published in the November 2007, edition of the Western Horse Review
BY JENN WEBSTER
The ability to take your horse’s body temperature is a vital horsemanship skill. As horses are warm-blooded creatures, their temperature should remain at a constant level, regardless of the ambient environment. This means, the range of normal body temperature is 37°C to 38.3°C, or 99°F to 101°F for the horse.
Monitoring body temperature is extremely useful in determining if the horse is ill or has an infection – or if the animal is on the road to recovery – and also for insurance or pre-purchase exams.
HOW TO TAKE A READING:
1. In the age of technology, using a digital thermometer is the easiest way to take a horse’s temperature. However, if you are required to utilize an old-fashioned mercury thermometer, ensure you shake the mercury line down below 36°C before proceeding. Attach a string with a clip securely to the end of the thermometer.
2. Lubricate the thermometer with water, saliva, Vaseline or KY Jelly lubricant. (2a, 2b)
3. Position yourself close in against the horse’s rear leg, just in front of the stifle.
4. Reach around the horse’s rear and lift up the horse’s tail.
5. Insert the bulb of the thermometer gently into the horse’s rectum and advance it at least two to three inches.
6. Clip the thermometer to the horse’s tail hairs and leave in place for one to three minutes. If the thermometer breaks or is swallowed by the rectum, it will likely come out with the next defecation. A swallowed, broken glass, mercury thermometer is an emergency situation – a string securely attached to the thermometer can help prevent this situation. Digital thermometers often ‘beep’ to signal they are finished taking the reading.
7. Remove gently.
8. Wipe the thermometer clean and note the reading.
If your horse’s temperature seems abnormal and the animal otherwise appears healthy, consider if there was an error made in the temperature reading. Air in the rectum during the time of thermometer insertion, a faulty thermometer, or failure to place it inside long enough can result in false readings. It’s also possible to inadvertently lock the bulb of the thermometer into a fecal ball, or neglect to shake the mercury line down far enough for the thermometer to take a correct reading.