Colonic Ulcers in Horses

Most of us know that horses can suffer from equine gastric ulcers syndrome (EGUS), a condition where horses develop ulcers in their stomachs. Horses can also develop ulcers in their large intestines. This condition is referred to as colonic ulcers or right dorsal colitis (RDC). In a recent study of 545 horses tested for RDC, 44% of nonperformance horses and 65% of performance horses had colonic ulcers. Although they are not as prevalent as gastric ulcers, colonic ulcers are still a significant problem, especially in performance horses.

RDC seems to be closely associated with stress. When horses become stressed, their bodies release natural steroids that can over time irritate and damage the lining of the intestine. The more stress a horse is under, the more damage occurs. The administration of non-steroid anti-inflammatory drugs (NSAIDs) such as phenylbutazone (bute) and Banamine has also been connected to the development of RDC for much the same reason; they irritate the lining of the intestine and leave it open to further erosion.

In the early stages of RDC, a horse will present with several nonspecific symptoms, such as recurring episodes of colic, poor appetite, dull hair coat, and lethargy. As the problem gets worse, an owner might see a complete loss of appetite, fever, colic, and diarrhea. Horses who are left untreated can develop dehydration, ventral edema (swelling under the belly and legs), and weight loss. Since these symptoms can be similar to other illnesses, such as Potomac horse fever and salmonellosis, it is best to contact your veterinarian as soon as possible so that they can rule out infectious causes and properly identify your horse’s illness. The veterinarian will use a combination of your horse’s history, blood work, and perhaps ultrasonic examinations to diagnose colonic ulcers.

If the veterinarian diagnoses your horse with RDC you will probably be asked to make some dietary changes. These may include:

• Discontinuing the use of NSAIDs, per your veterinarian’s directions.
• Reducing the bulk in your horse’s diet for several months by replacing dry hay with an alfalfa-based complete pellet that allows the colon to rest. The diet switch should be done slowly over 7 to 10 days to allow the digestive tract time to adjust. (Once the colon heals, the horse will be able to return to a normal diet.)
• Feeding frequent small meals to ease the physical load on the colon.
• Adding psyllium mucilloid to the diet. It will lubricate the feed and shorten the transit time through the digestive tract. It also increases the water content in the intestine, which is beneficial. There is some evidence that psyllium mucilloid increases the concentration of fatty acids in the colon and reduces inflammation.
• Providing additional omega-3 fatty acids to support healing. It has been shown that omega-3s block the chemicals caused by stress, and reduce inflammation.
• Supplementing with yeast metabolites and Saccharomyces boulardii. They provide much-needed nutrients to the intestinal tissues, reduce inflammation, and support quicker healing.
• Your veterinarian may also recommend any variety of medications that coat the ulcer and protect it while it heals.

Management changes that reduce stress—such as confinement to a stall or dry lot, a decrease in strenuous training, and a reduction in travel—should be implemented. Horses can be allowed to graze on fresh grass for 10 to 15 minutes at a time, 4 to 6 times per day, to reduce boredom while confined.

Generally it takes 1 to 2 weeks to see a reduction in symptoms once the above changes have been implemented. Swelling in the colon should begin to decrease in 4 to 6 weeks. Your veterinarian will probably monitor your horses on a routine basis by taking blood samples and possibly performing additional ultrasounds until the ulcer is healed. Most horses recover well from colonic ulcers, especially if treatment is started promptly.

Proper nutrition and feeding practices will help reduce the incidence of colonic ulcers. Horses that lead stressful lives or those with a history of colonic ulcers may benefit from continual supplementation with yeast metabolites and Saccharomyces boulardii, which are beneficial to the maintenance of digestive tract health.

Learn more about Kentucky Performance Products’ Neigh-Lox Advanced.