KNOXVILLE, Tenn. — Colonic ulcers are more common in their equines than horse owners know, caused and aggravated by a number of factors.

Just ask Dr. Frank Andrews. The University of Tennessee professor, also section chief of Large Animal Medicine with its College of Veterinary Medicine, is conducting research into intestinal equine ulcers. Everyone’s heard of the stomach variety – humans frequently blame the stressful “rat race” for theirs – but he said less attention is given to the colon.

“The trouble is that medications designed to work on stomach ulcers just don’t provide relief or treatment in the colon,” Andrews told those attending his presentation at a seminar last summer. He cited research from veterinarian Dr. Franklin Pellegrini which suggested the possibility up to 63 percent of performance horses may suffer colonic ulcers. This is a result of defect in the mucosa, or wall lining, of the colon.

Under normal circumstances, Andrews said a horse’s large intestine – the colon – is responsible for the uptake of water from manure. Occasionally, the mucosa’s ability to absorb is poor, resulting in diarrhea. A sort of reverse disorder results in the leakage of protein into the intestinal tract from the bloodstream, leading to edema (fluid beneath the skin).

An ulcer is an open sore on the colon wall irritated by normal daily usage.

“That’s what we’re really talking about, colons that don’t function well,” Andrews explained.

Various stressors can lead to colonic ulcers. The cause with which he is most concerned is the strongyle, a parasitic worm transmitted by mites.

Their larvae develop in the horse’s colon and burrow into the mucosa.

“The problem with this parasite is they actually invade the colon and then become dormant during winter months,” Andrews said.

Strongyle eggs are passed in fecal matter and may hatch to infect other equines.

Other causes of colonic ulcers include:
•Salmonella
•Inflammatory Bowel Disease (similar to Irritable Bowel Syndrome in humans), which can lead to chronic ulcers
•Cancer
•Usage of anti-inflammatory drugs (such as banamine or phenylbutazone)
•Stress

Of these, stress probably sounds the most vague. Andrews explained it can be any type of stress; for example, a horse which is left stalled too long and then turned out among others suffers the stress of fitting back into a social “pecking order” with those animals. Overcrowding of horses is another possible stressor; so is diet.

“Because we’ve domesticated the horse, we’re probably more aware of the stresses on them,” he pointed out – compared to, say, cattle.

Clinical signs equine owners want to watch for include periodic episodes of illness; colic (chewing or kicking at one’s side or rolling); lethargy; loss of appetite; diarrhea; intermittent fever; dehydration; edema; weight loss; a thinning of the coat; or a darker red color to the gums.

Another clue goes back to the anti-inflammatory drugs – if a horse is taking one for chronic lameness or an injury and the diagnosing vet doesn’t already know, it is something of which they should be notified.

Ulcer treatments
While advanced ulcers are difficult or impossible to treat, many can be caught in time and, with proper care, healed.

Andrews prescribes for his patients a decrease in the bulk of raw roughage in their diet, since it serves to irritate an ulcer.

Eliminate hay gradually over a period of seven to 10 days and replace with a “complete” feed (such as Purina Equine Senior Diet with an alfalfa base).

He combines this with medication such as Sucralfate, which adheres to ulcerated tissue and “makes a bandage” over it. Often his regimen also calls for something as simple as adding a laxative, or corn or flaxseed oil to the horse’s diet, to ease pressure on the ulcer.

Part of Andrews’ particular research includes studying the effects of Succeed, an equine nutritional supplement manufactured by Freedom Health, LLC of Ohio, touted to keep a horse’s digestive tract healthy. The company is relatively new, he said, and is gathering experimental data through researchers like him.

“There’s no data whether it’s helpful or not,” Andrews explained, “but it’s out there.”

Andrews further advises his patients’ owners to keep up this combined regimen for three to four months.

Above all, the main principle for treatment of an ulcer is to look for and correct its underlying cause, be it environmental stress, drugs, parasites or disease. Repairing the ulcer doesn’t do much good, after all, if what caused it has a sure chance of doing the damage again.

This farm news was published in the March 22, 2006 issue of Farm World.