Colic in Horses

Updated May 2011

Colic is the term often used to describe any abdominal pain or discomfort in a horse. There are many causes, some of which are more serious than others.

Colic can not always be prevented, but there are some steps that can be taken to reduce the chances of it occurring. Always allow your horse free access to fresh, clean water. Make all feed changes gradually mixing old feed with the new. Allow hay to cure/sweat at least 30 days from the time it is baled to the time you feed it. Minimize parasite load by proper stall/pasture management and deworming. Avoid feeding horses on the ground especially in sandy areas. Never feed rotten or moldy feed. Allow exercise opportunities for your horse on a daily basis either with pasture turn out or riding. These are all steps that can help minimize the chance of your horse experiencing colic.

The basic signs a colicky horse may exhibit are restlessness, shifting weight on its legs, pawing, looking back at its belly, kicking at its belly, frequently rolling, reluctance to move, loss of appetite or desire to drink, throwing itself on the ground, or sweating unexplainably. Not all horses will show all of these signs, and signs may in fact be subtle. 

Some causes of colic involving the gastrointestinal tract may include:

·         Spasmodic/gas colic which is often a build up of gas in the intestines.

·         Impaction, when the intestines are obstructed by feed, foreign material, sand, or parasites.

·         Displacement, when a section of the large colon becomes trapped in an incorrect place or position in the abdomen.

·         Torsion or twisted gut, when the intestines actually are displaced and twist back on themselves obstructing flow of feed and impairing blood supply. 

·         Extra luminal obstruction, when something outside of the GI tract impinges on it such as a mass or strangulating lipoma (fatty tumor).

Any of these can occur in the large or small intestines although some are more common to involve the small intestines and some more commonly involve the large intestines.

It can be difficult to assess the severity of the colic episode. Some parameters that can be looked at include:

• Heart rate: a heart rate greater than 60 beats per minute can indicate a more serious colic and often a heart rate greater than 70 is highly suggestive for surgical management.  
• Gut sounds: if none are heard this may indicate that the GI tract is not working, also if very loud frequent sounds are heard this can indicate over exertion or gas build up in the GI tract.
•  Mucous membranes: the gums should be pink. When pushed on they should turn white (blanch out) and then return to pink in less than two seconds when your finger is removed. This procedure is commonly referred to a capillary refill time or CRT. If the gums are pale white this may mean the horse is in shock, if they are bright red the horse may have an endotoxic reaction, and if they are purple this may indicate poor blood perfusion. A slow CRT also indicates poor perfusion.

You must know what is normal for your horse to detect what is abnormal.

If you suspect that your horse is colicky you should have your veterinarian examine the horse. Prior to your veterinarian’s arrival you should keep the horse walking, this will prevent the horse from rolling. Rolling increases the chance of a medical colic turning into a surgical colic because the distended intestine is more apt to twist or torse than a normal healthy intestine. Often getting the horse into a trot, or a short trailer ride will cure a gas colic or a mild impaction. Horses should not be ridden as they can go down unexpectedly but can be worked in a round pen or ponied by another horse. Some horses will be uncontrollable and go down and roll without any notice so owners and helpers need to use caution as human safety should be their first priority.

When your veterinarian arrives they will be better able to determine the severity and possible cause. They will assess heart rate, mucous membranes, gastrointestinal sounds, and perform a general physical exam. Often the veterinarian will rectally palpate the horse to feel for impactions, displacement, obstructions or torsions. However not all of these can be palpated. Normally only the back third to half of the GI tract can be palpated depending on the size of the horse and the arm length of the veterinarian. The veterinarian will often also pass a nasogastric tube down the horse’s nose. If there is excessive gas or fluid in the stomach it will often indicate that the source of the colic is in the proximal small intestines. Only after the horse has been thoroughly examined can a proper treatment program be implemented. 

Treatment options include medical and surgical treatment. Basic medical treatment for simple colic often involves fluid therapy via the nasogastric tube and medication to manage pain and/or relax the gastrointestinal tract. More advanced medical management may include hospitalization, IV fluids, or different drugs for pain management, an indwelling nasogastric tube and other supportive care as needed. Surgical treatment often involves an exploratory surgery of the abdomen and correction of the primary problem. Most surgical cases will have to be stabilized and transported to a surgical facility.