Equine Colic

By: Mary Newell Sanders, DVM

TVMA Member
Bellville, TX

Published June 2014

Photo by Dr. Tracy Fant Colvin

What is Colic?

Colic is a general term used to refer to abdominal pain in horses. There are a number of different types and causes of it in Texas. Whatever the type or cause, it is a serious condition, as it is responsible for more equine deaths than any other disease. Approximately seven out of every 100 horses will experience colic at some time during a year’s span. Fortunately, 80 percent of those cases are mild cases and will resolve with medical therapy. Only two to four percent of colic cases are severe enough to require surgery. There are some predispositions to colic.

Clinical signs of colic include laying down and not wanting to get up, rolling, biting at the abdomen, pawing and not eating. If you are able to listen to your horse’s chest and abdomen, you may notice an increase in heart rate and decreased and/or absent gut sounds. The average 1,000-pound horse will have a heart rate of approximately 30 to 50 beats per minute and will have large gut movements one to two times per minute. The more pain your equine is in, the higher his heart rate will be. Absent gut sounds typically indicate a more severe case of colic than do decreased gut sounds.

Types of Colic

There are four main types of colic: impaction, gas, volvulus and inflammatory. Impaction colic results when hay or other materials obstruct the intestinal opening. Gas colic occurs secondary to excess gas formation and can often lead to volvulus, or twisting of the intestine. Inflammatory colic, also known as anterior enteritis, is characterized by inflammation and swelling of the intestine and loss of intestinal activity. The exact cause of this type is still unknown, though some believe it occurs secondary to bacterial overgrowth within the small intestine.

Causes and Prevention

There are, however, a number of causes that the owner can control. The key to reducing your horse’s risk of colic lies in good equine management.

Sudden changes in grain or type of hay are a very common cause of colic as is overfeeding. Find a good, high-quality feed that is appropriate for your horse’s life stage and feed only that to your equine. Do not frequently switch brands or types of feed. Also, make sure that you are feeding your horse the appropriate amount of grain. Suddenly increasing the amount of grain your horse eats increases the risk of colic.

Remember that horses are grazers. They are naturally meant to have small amounts of food in their stomachs at frequent intervals. If you feed your equine grain, divide the daily ration into two or three smaller meals. Don’t feed the entire ration in one feeding. Ensure that your horse’s hay contains highly digestible fiber since poor-quality forage predisposes your horse to an impaction. Make sure your horse’s pasture is in good condition. Overgrazed pastures expose your horse not only to sand but also to parasites, both of which are common causes of colic. If your pasture doesn’t have a lot of grass or your equine is kept in a dry lot, do not feed it on the ground. This increases sand and parasite egg ingestion. Have a good deworming program in place. Not all larval stages are killed by routine dewormers, nor are tapeworms.

Thoroughbreds and Arabians tend to colic more than other breeds. Horses younger than two years and older than 10 years are less likely to it than middle-aged horses. Horses that have had previous episodes of colic are more prone to have repeat episodes.

Finally, your horse is more likely to colic if he has had a sudden decrease in exercise. Movement is required for gut motility, so your equine is much better off on a well-maintained pasture than in a stall.

There are a number of causes of this disease that are unique to Texas. The majority of colics in Texas are impaction colics due to the large amount of coastal Bermuda grass hay that is fed. Also, Texas is prone to sudden weather changes. Water consumption in horses decreases when the temperature changes drastically from morning to evening. During the cooler nights in Texas, your horse doesn’t sweat as much and therefore doesn’t drink as much water. The temperature rises quickly the next day, and your equine is consequently not well-hydrated and can quickly become colicky. To combat this in Texas, add table salt or electrolytes to your horses feed during the spring and fall seasons or any other time when the temperature changes more than 30 degrees in a 24-hour period.

Treatment for Colic

If you see your equine colicking, immediately call your veterinarian. It is best not to give any medication or initiate any kind of treatment without your veterinarian looking at your horse first. Your veterinarian will perform a thorough physical exam to determine the cause and severity of the problem. They may check mucous membraneA tissue that secretes mucous and that lines many body cavities and tubular organs including the gut and respiratory passages. color, take a heart rate and listen for gut sounds. He or she may also rectally palpate your horse and/or perform an abdominal ultrasound to better assess your horse’s gut function. Your veterinarian may also recommend bloodwork, fecal assessment or abdominocentesis (drawing fluid from the abdomen). Treatment varies depending on the type of colic, but typically your veterinarian will give your equine some pain medication and pass a nasogastric tube through your horse’s nostril into the stomach. Your veterinarian can then look for reflux and administer water, electrolytes, mineral oil or anything else deemed necessary to make your equine more comfortable. It is often necessary to place an intravenous catheter and begin fluid therapy. Your horse may need to be hospitalized for further treatment and, in severe cases, may require surgery.

Surgery is the recommended treatment for those types of colic that can’t be managed medically, like a volvulus (twisted gut). Surgery is also recommended for horses that are unable to be kept comfortable with medical management alone. In surgery, an impaction can be manually removed, and large amounts of gas and/or fluid can be drained from the intestines. The surgeon will also examine each part of the intestine to make sure it appears healthy and may remove pieces that appear seriously damaged. Colic surgery is major abdominal surgery, and there are many complications that can arise post-operatively. Therefore, horses are kept hospitalized to ensure that they do not develop any signs of infection as well as to ensure that they begin eating and drinking and are passing normal amounts of urine and stool.

This is a very serious illness in horses. There are a number of different causes, but fortunately, you as the owner can greatly reduce your horse’s risk by implementing good management practices. If your horse does colic, learning to identify the clinical signs and seeking immediate medical attention will give your horse the best chance at a full recovery.

Dr. Mary Newell Sanders practices at Marek Veterinary Clinics in Bellville and Sealy, Texas.