Jeske Noordergraaf, VMD

Horses don't pretend.  If your horse won't move when normally he is happy to go into the barn, there is probably a problem.  Before calling your veterinarian, it is helpful to determine the cause of the pain so that we can bring the needed equipment along and schedule accordingly.  I am going to go over normal values so you have something to compare to.

 Taking a horse's temperature is done rectally.  We use a human digital thermometer and just hold it for the two minutes that it takes to register.  If you are wondering if the thermometer works, try it on yourself or in water.  Normal horse temperature is 100° +/- 1°.  If a dark horse has been standing in direct sunlight or a foal has been running around, it may be higher.  Wait for the horse to cool down and take it again.  Elevated temperatures are generally caused by infections.  Pain may also cause a slight increase in body temperature.  Most colics have a normal temperature.  A low body temperature may indicate that the horse is in shock.  If you still have an old glass thermometer, use that.  I have never heard of a horse sucking the thermometer into the rectum but the string and clip on the end which you fasten to the tail keeps the thermometer from falling onto the ground and breaking.  Teaching your horse to stand still while the temperature is taken will be greatly appreciated by your veterinarian.

 A normal horse respiratory or breathing rate is 12 – 16 breaths per minute.  We usually count the breaths that the horse takes in a fifteen second  period and multiply by 4.  The nostrils should not flare unless the horse has been working hard.  A horse at rest should not have wide nostrils and the ribcage movement in and out should barely be noticeable.   Several common causes for an increased respiratory rate are heaves (chronic obstructive pulmonary disease), pneumonia, and obstructions.  Normal discharge from the nose is clear and non odorous and small in amount.  Yellow or green nasal discharge may indicate that your horse has an infection.  Food comes out of the nose when there is an obstruction in the esophagus, a choke, which is a true emergency.

 The heart rate can be measured either by using a stethoscope over the heart or by light digital pressure over an artery.  The easiest artery to use is the facial artery as it goes under the jaw bone.  Very light pressure is needed to feel the pulse and most people comment on how slow the rate is.  Again, we count for fifteen seconds and multiply by four.  Normal heart rate for a horse at rest is 32 – 40 beats per minute.  Pain makes the heart rate increase.  The severity of a colic is usually related to the increase in heart rate.  A horse with a pulse over 100 beats per minute needs surgical intervention while one with a pulse of 46 might do fine with medical treatment.  Next time you have the vet out, ask them to demonstrate taking the pulse.

 Gum or mucous membrane color represents the status of the circulation in the body.  Pale gums are seen with blood loss, anemia or shock.  Brick red gums or gums with a toxic ring which is when it is darker just around the teeth, correlate with a  horse where bacteria are releasing toxins into the blood stream.  This horse needs to be seen by a veterinarian as soon as possible.  Lastly, we measure the capillary refill time in the gums.  This is done by pressing on the gum with one finger which turns it white, then we count the time it takes to regain the original color.  If the blood isn't circulating well in the horse, the capillary refill time will be prolonged.  Normal capillary refill time is 2 seconds.

 Horses enjoy eating and there is always food in the gastrointestinal tract.  Normal borborygmal or gut sounds should thus always present and you should hear 1-2 good contractions per minute.  It is not normal to have a completely quiet belly.   Manure is produced every few hours.  A lack of manure during the night can indicate an impaction.  Diarrhea also is a sign that something is wrong.  Both of these probably warrant a visit from your veterinarian.   Overactive guts may go along with diarrhea or colic, something is irritating the gut such as sand or a toxic plant.  Take a listen while your horse is normal so that you know what is normal. 

 Hooves should feel cool and the digital pulses on the back of the fetlock should barely be palpable.  Increased blood flow to an area indicates that there is inflammation as with laminitis or a hoof abscess.   It is better to treat a laminitic horse early to help prevent  further problems.

 So is your horse sick?  In veterinary school they teach us that you need to know normal to recognize abnormal.  Learn your horse's normal values and impress your veterinarian.