Colic is a general term that refers to abdominal pain, rather than a specific disease.  It most commonly originates from the gastro-intestinal tract but may be related to organs from other body systems, such as the kidneys or ovaries and uterus, also found in the abdomen.  The GI tract itself can be broken down into segments including the stomach (where ulcers commonly occur), small intestine (which can become inflamed, twisted, or blocked), and a rather extensive large intestine (which can fill with gas, become displaced, or be impacted with sand or feed material).

Signs of Colic:  As colic refers to pain, the signs become more intense and easily recognized as the pain grows worse.  A horse with mild colic may appear restless: not interested in eating and lying down more frequently.  A moderately painful horse will often turn its head toward or kick at its flank, repeatedly stretch as if to urinate, and sweat.  A very painful horse will drop to the ground and roll; as they become increasingly painful, horses no longer consider their own safety or that of those around them.  These intensely painful horses can be dangerous as they thrash about, injuring themselves and potentially others.

The amount of pain shown by a horse is closely related to the severity of the disease.  For example, intestinal torsions which cut off blood flow require surgical correction and are very painful.  Fortunately, colic episodes requiring surgery make up less than ten percent of colic cases.  Most are relatively mild caused by increased gas or intestinal movement and resolve with medical management.

Causes of Colic:  There are many causes and contributing risk factors for colic.  The most important include changes in feed or environment, access to water, and intestinal parasites.  Horses are herbivores and while their stomach and small intestines are similar to ours, they have a greatly expanded large intestine, filled with good bacteria that help them ferment and digest tough plant material.  The large intestine, in a sense, has its own mini-ecosystem which must remain in balance in order to function.  It functions best with a consistent diet made up mostly of roughage (hay or pasture) with limited concentrate (grain).  Horses, therefore, can be very sensitive to changes in their diet, such as being turned out onto lush pasture for the first time in the spring, or a sudden increase in grain.  Rich alfalfa hay can also cause colic, so we recommend feeding a grass hay or grass/alfalfa mix.  Changes in management or a horse’s routine can be stressful and contribute to colic risk as well.

Water is also very important, as a horse with minimal exercise needs to drink 4-5 gallons a day to remain healthy.  Vast amounts of water are secreted into and absorbed from the horse’s gut daily.  Therefore, ensuring your horse has access to fresh, clean water is very important.  If they do not have enough water, the feed material can become hard and impacted in the colon, blocking movement.  In the winter, make sure that your horse’s water source is not frozen (or very cold) with use of heated waterers or meticulous management.  In the summer, horses can lose large amounts of water through sweat, particularly if they have been exercising, so make sure to provide extra.  When traveling, some horses will not drink water from a new place, so make sure you bring your own water or prepare them for a change by adding a flavoring (such as peppermint) to their water at home prior to departure and then the same to the new source.

Intestinal parasites can lead to colic, particularly in the young horse.  Heavy infestations of roundworms can get stuck in the intestines blocking movement of feed material.  Tapeworms can irritate the lining of the intestine and cause it to telescope on itself, known as an intussusception.  These both require surgery.  It is important to have your horses on a regular deworming schedule including a product that contains praziquantel, as this is effective against tapeworms.  Adult horses should have regular fecal exams to customize a deworming schedule and make sure the products used are effective.

Managing Colic:  Despite your best efforts to prevent colic, there is still a chance that your horse will colic at some point during his/her life.  If this happens, the first thing to do is remain calm and assess your horse’s level of pain.  Think about any recent changes in feed, management, water access, or deworming.  These are all things that your veterinarian will ask you, as calling him/her is the next step.  It is impossible to know just what is going on without a veterinary exam.  While you are waiting for the vet to arrive, walking your horse can help to encourage GI movement and gas expulsion.  Your veterinarian will look at your horse’s gums, take a pulse and listen to GI sounds.  He/she may also do a rectal exam and pass a tube through the nose into the stomach (naso-gastric tube).  The rectal exam may tell if some parts of the colon are out of place, distended with gas, or impacted.  The naso-gastric tube allows the vet to check for reflux (meaning fluid is stuck in the stomach because it cannot continue through the intestines) and administer fluids and mild laxatives (e.g. mineral oil) if necessary.  Your veterinarian may also give an injectable sedative to facilitate procedures, which has a pain relieving effect as well or an anti-inflammatory such as banamine.  At this point, your veterinarian will have an idea of what is going on and can give you instructions for further management.  For mild cases, this may be withholding grain and slowly re-introducing hay over a couple of days, or may include more intensive management such as additional fluid administrations for some cases.  If your horse requires surgery, you will be referred to a surgical facility for further workup.

Colic is the most common emergency seen in horses, and can be quite scary even for the most experienced owners.  Maintain your horse on a consistent diet of high quality forage with limited concentrate; make all changes to feed or management gradual if possible; ensure access to fresh, clean water all year round; and limit intestinal parasites through strategic deworming and fecal exams.  If your horse colics, call the veterinarian immediately, before administering any medications and follow their directions carefully after their visit to ensure an uneventful recovery.