Taking Temperature

Choose an animal thermometer that has an eye at the end. Thread a string through the eye and tie a small clip or clothespin to the end. Check the thermometer to be sure it is reading below 96 degrees. If it registers a temperature from the previous use, hold it securely at the top and shake it sharply to get the mercury to drop down. Then apply a small amount of lubricating jelly to the business end of the thermometer. The lubricating jelly should be at room temperature, somewhere around 65 degrees. An assistant should be holding your horse, or your horse can be tied if he is used to having his temperature taken. Move your horse's tail off to one side. This tends to cause less tension in the horse than lifting the tail up. You will be inserting the thermometer into the anus at a slight upward angle. Gently ease the thermometer inward and upward until about 2" remain outside the anus. Do not insert the thermometer all the way. If you do, it has a greater chance of contacting warm fecal material, which will give you an inaccurate reading. Move the tail back into position. Clip the string onto the horse's tail so that in case the horse defecates suddenly, the thermometer won't drop to the ground and break. After two minutes, take the reading. Wash your hands and the thermometer with antibacterial soap when finished. The range of average resting temperatures for adult horses is 99-100 degrees. Temperature increases with exertion, excitement, illness, and hot, humid weather. Temperature decreases with shock, and a horse's temperature can also be a few degrees lower in very cold weather.

Taking a Pulse

Choose an artery close to the surface of the skin. Lightly press your fingertips against the artery. Count the beats for 15 seconds and then multiply by 4 to get the rate per minute. The maxillary artery, on the inside of the jawbone, is one of the easiest places to find a strong pulse, even on a quiet, resting horse. It's best not to let your thumb rest on the horse when you take a pulse as you might pick up a throbbing from your own heartbeat and get a misreading. Another easy-to-find pulse spot is the digital artery located on both the inside and outside of the horse's leg, just above the fetlock.
Normal resting pulse rates are as follows: 2 weeks old - up to 100; 4 weeks old - 70; Yearling - 45-60; 2 years old - 40-50; Adult - 30-40.

Measuring Respiration

A horse's normal resting respiration rate is usually between 12 and 25 breaths per minute. A foal's rate will be at the high end of the scale. One breath is measured as one inhalation and one exhalation. The ratio of the pulse to the respiration rate is often a more significant measure of stress than each of the actual figures. Depending on the horse's age, his normal resting pulse to respiration ratio should range from 4:1 to 2:1. If the ratio becomes 1:1 or 1:2 (called inversion), the horse is suffering from oxygen deprivation, which indicates serious stress. Call your veterinarian immediately.
When a horse is exercising heavily, it is easy to measure his respiration rate by watching his nostrils dilate and relax or by watching his ribs move in and out. The best way to determine a respiration rate is to use a stethoscope on the trachea. Press the bell firmly into the underside of the horse's neck about 4 inches below the throatlatch. Count for 15 seconds, and multiply by 4. Alternatively, you can listen to his lungs, but it takes more practice and experience to obtain a respiration rate this way. Place the stethoscope midway down the heart girth on the left side. You will hear the quality of the breathing process in his lungs but might not be able to identify definite breaths.

Using a Stethoscope

To determine a pulse or listen for heart function abnormalities, press the bell of the stethoscope into the horse's left armpit area. If you are using this method to take the pulse, count the heartbeat for 15 seconds and multiply by 4 to get the number of beats per minute. To listen to the intestines, select several sites on both sides of the horse. Steady the horse by placing your left hand on his back and using plenty of body-to-body contact with your left arm and shoulder. This way your horse won't be surprised when you place the bell of the stethoscope firmly into his belly. Become very familiar with what your horse's intestines normally sound like by spending 5 to 10 minutes for several days in a row listening to his gut both before and after he eats. As you move the stethoscope to other locations on the abdomen, try to classify the nature of the sound you hear to develop an ear for what is normal. Generally, you want to hear a moderate amount of gurgling, creaking, and swooshing. No sound could mean that the contents of your horse's intestines have become bound up (impacted), often from lack of proper moisture. Excessive gut sounds could be normal or could mean the horse has a hyperactive gut or diarrhea, such as might occur from a succulent pasture or rich alfalfa hay.