Temperature, pulse, and respiration (TPR) are the three important vital signs you must know how to check if you own or ride horses, especially during an emergency situation. In January, Doug Byars, DVM, Dipl. ACVIM (internal medicine), ACVECC (emergency and critical care), of Byars Equine Advisory LLC in Georgetown, Ky., showed us four ways you can take a horse's pulse. He rejoins us this month to discuss how to monitor a horse's temperature and respiratory rates, as well as capillary refill time.

Temperature

A fever or subnormal temperature in a horse can be one of the first signs of a problem. A horse's normal temperature ranges between 99°F and 100.5°F. This range can vary from horse to horse and, Byars says, can be influenced by exercise or the environment. However, a temperature greater than 102°F in an adult horse at rest can be a cause for alarm and could mean there is an infection or other ailment affecting the horse.
 

NORMAL TPR RANGES

T emperature: 99-100.5 °F P ulse: 36-44 beats per minute R espiratory rate: 8-12 breaths per minute Mucous membranes: Pink Capillary refill time: Refill within two seconds Note: These are common averages. Monitor your horse's vital signs over several days to detect his normal ranges.

Foals are a little different in that a low temperature is more often an indication of a problem. "A foal or neonate will often have a lower-than-normal temperature rather than a fever when they have an infection," Byars says.

He explains, "The best way to take your horse's temperature is with a normal rectal or digital thermometer inserted into the horse's anus for about two minutes."

Respiratory Rate

An increased respiratory rate can be another indicator that something is wrong with your horse. A horse's typical respiratory rate at rest is eight to 12 breaths per minute. One way to take your horse's respiratory rate is to watch for him to exhale and count the nostril flares or the expansions of his rib cage or flank. However, Byars explains that the best method of monitoring a horse's respiratory rate is by using a stethoscope to listen to the inspirations in the chest or the windpipe.

"You can purchase an inexpensive stethoscope for about $10-20," Byars says.

For either method, count the breaths for 15 seconds and multiply that number by four to quickly calculate the number of breaths per minute.
Exercise, heat stress, nervousness, pain, and illness can all be factors causing an increased respiratory rate. A normal respiration rate is steady and effortless. If your horse has irregular, shallow, labored, or noisy breaths, this could be a sign of a serious problem and you should contact your veterinarian.

Mucous Membranes  

Mucous membranes line the body cavities that are exposed to the air such as the nostrils, around the eyes, and inside the horse's mouth. The  membranes' color can indicate the quality of the blood flowing through these areas. Healthy horses have a pink mucous membrane color. A bright red color indicates illness or fever, while a pale color can be a sign of anemia, and a dark red or bluish color can indicate shock or poor circulation.

In addition to color, monitor how long it takes the capillaries (blood vessels) within the mucous membranes to refill after pressing on the gum. A capillary refill time (CRT) longer than two seconds could be a sign of poor blood circulation or shock.

To take your horse's CRT, pull up your horse's top lip, press firmly on the mucous membranes above your horse's teeth with your thumb, and release after about three to four seconds. When you lift your finger, you should see a white area that should fill back in with color within one to two seconds. If the area takes longer than three seconds to refill, contact your veterinarian.

Take-Home Message

These vital signs can be a window to your horse's health and can help you intercept illness or other problems early. Become familiar with your horse's normal TPR values and monitor them regularly for any changes that might be signs of a health problem.