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Know Your Horse’s Vital Signs

Everybody who owns, rides or handles horses should know their horse’s vital signs. These simple checks will help tell if your horse is healthy or if you will have to call the vet. By being able to tell your veterinarian these simple but crucial parameters during an emergency (often when you have to give information over the phone), you will get more accurate and appropriate treatment for your horse.

Your horse’s vital signs should be regularly monitored. It may be a good idea to write them in a diary and keep a note on the horse’s behaviour and general condition. This will give you an idea of what your horse’s normal vital signs are.

Temperature

How to measure
The best way to take the horse’s temperature is rectally. Keep a plastic digital thermometer in your medical kit. They are safe, easy to use, inexpensive and available at most pharmacies and are operated by pressing a button to turn them on. Simply lubricate with petroleum jelly (Vaseline) and insert the thermometer into the horse’s rectum.

“Always clean the thermometer well before returning it to its case…and especially if used on an ill horse, to prevent the spreading of an illness.”

It may take one to three minutes for an accurate reading, although many digital thermometers take readings quickly and beep when they are done. Simply read the digital display for the horse’s temperature.

(Note: So you don’t lose the thermometer in your horse, attach a piece of string to the handle end along with an alligator clip. When the thermometer is inserted, fasten the alligator clip to tail hairs, thus securing it!)

Understanding the information
Normal body temperature is 37-38° C, but environmental factors can affect the readings by 0.5-1° C. Horses tend to have higher temperatures in warm weather. Exercise, stress or excitement will raise temperature as well.

This is why it’s important to take your horse’s temperature many times and in many different situations so you will know what the norm is. Respiratory colds and infected cuts usually generate temperatures in the 39-40°C range.

Viral infections cause either early subnormal temperatures (similar to chills one feels with a viral cold) or very elevated temperatures, 41-42°C.

Occasionally, infections will cause biphasic fevers that show a normal temperature in the morning, but will spike a high temperature in the afternoon. When you are concerned about possible illness, record the horse’s temperature twice a day and look for patterns and changes.

The Pulse

How to measure
The pulse in the horse can be taken from an area under the jaw, from beneath the tail at its bone, or from an area on the side of the horse’s foot. The simplest and most effective way is by placing your hand or stethoscope on the left (near) side of your horse’s chest under the elbow. (If you can’t find the pulse, your veterinarian will be happy to show you.)

Since most horses will not stand still enough to count heartbeats for a full minute, count for 15 seconds and multiply by four.

“Be sure to count each lub-dub as 1 beat.”

Understanding the information
The pulse measures the rate and strength of the heartbeat. A normal resting horse has a heart rate of 38-40 beats per minute, foals (70-120 bpm), yearlings (45-60 bpm) and 2 year olds (40-50 bpm).

Maximum heart rates can exceed 180 beats per minute, but a rate above 80 should be considered serious in most non-exercising horses. Heart rates that stay above 60 in a horse that is calm can be a sign of trouble.

Exercise, stress, fear, pain and excitement will elevate the horse’s heart rate. Infection will cause an increased rate, as will traumatic cuts, kicks, fractures and so forth.

The most common cause of elevated heart rate is colic or intestinal pain. Such pain can cause mild to severe elevations, and the degree of increase can be a sign of the severity of the colic pain.

The intensity or force of the pulse is sometimes an indicator of other problems in the horse. A weak or soft pulse means the heart is not pumping forcefully and may indicate heart disease.

A hard, forceful pulse can be felt in a horse that has been exercising and is pumping a lot of blood to carry oxygen to working muscles.

This forceful pulse can also be felt as a reaction by the body to some drugs, toxins or some disease conditions. Knowing your horse’s normal heart rate and pulse quality allows you to make comparisons in order to evaluate situations and judge your horse’s response.

Textbooks on conditioning the sport horse will also make mention of the rate of return, after exercise, to a normal heart rate. This statistic is the single most effective indicator of fitness in horses. Being able to simply take your horse’s heart rate allows you to evaluate and monitor training and fitness in your equine athlete.

Respiration

The average respiration rate of a mature horse at rest is 8-15 breaths per minute. A horse’s respiration rate increases with hot or humid weather, exercise, fever or pain. Rapid breathing at rest should receive veterinary attention, and keep in mind that the respiration rate should NEVER exceed the pulse rate. A horse should also spend equal time inhaling and exhaling. You should wait at least 30 minutes after work before checking the respiratory rate at rest to obtain a true reading.

How to understand the respiration rate:
Watch or feel your horse’s ribcage/belly for one minute. Be sure to count 1 inhale and 1 exhale as one breath (not as two). Each breath is fairly slow. If you are having difficulty seeing the ribcage move, try watching the horse’s nostrils or place your hand in front of the nostrils to feel the horse exhale.

An even better method is to place a stethoscope to the horse’s windpipe to listen to his breathing. This will also give you strange sounds if the horse’s windpipe is blocked by mucous or if the he has allergies or heaves.

Gut sounds

The gut sounds that come from your horse’s stomach and intestines can be very important information, which your vet uses to diagnose an illness. Gut sounds should always be present. The absence of gut sounds is more indicative of a problem than excessive gut sounds. Usually, an absence of gut sounds indicates colic. If you don’t hear any sounds, contact your veterinarian.

How to check for gut sounds:
Press your ear up against your horse’s barrel just behind his last rib. If you hear gurgling noises, he’s fine. Be sure to check gut sounds from both sides.

If you do not hear any sounds, try using a stethoscope in the same area.

Dehydration

Healthy horses drink a minimum of 20 litres of water per day. If your horse is dehydrated, it is very important that you urge him to drink. If he refuses to drink water, try adding flavour to it (molasses or cordial is ideal), and contact your veterinarian if he still won’t drink. During hot, humid conditions horses should drink a lot more. A horse in race training in these conditions may drink up to 70 litres per day. To ensure you have an indication of your horse’s water consumption, it may be wise to use buckets instead of waterers if horses are continually stabled.

How to perform a pinch test:
Pinch the skin on your horse’s neck. If the skin flattens back into place in less than 1 second when you let go, the horse is fine. If it doesn’t, it means he isn’t drinking enough water and is dehydrated.

The longer the skin stays pinched up before flattening, the more dehydrated the horse is.

Capillary Refill Time (CRT)

Capillary Refill Time (CRT) is the time it takes for blood to return to blanched tissues in the gums. This is an indicator of blood circulation. Normal refill time is 1 to 2 seconds.

How to check CRT:
Lift your horse’s upper lip up and firmly press your thumb against his gums for 2 seconds to create a white mark. This white mark should return to the normal pink colour within 1-2 seconds after releasing the pressure.

If the CRT takes longer than 2 seconds, the horse may have shock.

Mucous Membranes

The mucous membranes are the lining of a horse’s eyelids, his gums and the inside of his nostrils. The colour of the mucous membranes, are another indicator of blood circulation. A healthy horse’s gums are slightly paler than a human. If a horse’s gums are very pale, bright red, greyish blue or bright yellow, call a veterinarian immediately.

Colour of mucous membranes
Moist Pink: Healthy normal circulation.
Very Pale Pink: Capillaries contracted, indicates fever, blood loss or anaemia.
Bright Red: Capillaries enlarged, indicates toxicity or mild shock.
Grey or Blue: Severe shock, depression and illness.
Bright Yellow: Associated with liver problems

If you witness any signs which may alert you to a problem with your horse. It is always wise to seek the advice of your veterinarian sooner rather than later as the earlier a vet can examine your horse the more time they will have treat the problem.

Article courtesy of David Nash BSc and HyGain Feeds Pty Ltd