Psyllium Mucilloid Effective In Removing Intestinal Sand?

Horses living near a coast or in the warm desert sun might seem to have a luxurious life, but many equines in these areas are threatened by abdominal sand on a daily basis. These occurrences were a problem for a group of veterinarians from Arizona Equine Medical and Surgical Center (AEMSC). Those practitioners studied 24 horses suffering from intestinal sand between 1991 and 1993. This previously unpublished study reported that psyllium (horse-strength Metamucil) could be an effective means of eliminating sand from the gut of a horse. This contradicts a study that said psyllium is ineffective for helping a research pony rid sand placed in his cecum.

Mark Revenaugh, DVM, was a collaborator in the Arizona study. He now works with B.W. Furlong & Associates veterinary firm in New Jersey. Revenaugh explained that many horses ingest sand on a daily basis in the Phoenix Valley, and he recalled cases where up to 50-60 pounds of sand were found in the right dorsal colon. "(In surgery) you had to be careful that you didn't tear the colon--it was like picking up a bag of concrete," he said.

Veterinarians are not sure why the horses ingested the sand, but Revenaugh said there were no indications that horses had a mineral imbalance that might have caused the consumption. In fact, questionnaires returned by the horse owners did not verify any significant management issues that would contribute to such behavior except that they were fed at ground level.

After seeing so many horses suffering with a virtual beach in their GI tract, Revenaugh, Gayle Leith, DVM, MS, ABVP, and Kent Allen, DVM, (now of Virginia Equine in Middleburg, Va.), all of whom were practicing at AEMSC at the time, began a study that involved 24 horses suspected of suffering from intestinal sand build-up. Symptoms were abdominal discomfort (38% of the admitted horses), weight loss (38%), or diarrhea (24%), all with sand in the manure and characteristic abdominal sounds. All diagnoses were confirmed by observing sand on abdominal radiographs, and each horse underwent a full physical examination. Horses were started on a daily dosage of psyllium, then evaluated monthly.

Although the mechanism of action is uncertain, it is suspected that psyllium acts as a bulk laxative. "If you take (psyllium) and wet it, it almost forms a gelatin-like substance, which seems to blot up the sand," explained Leith.

It's believed by these veterinarians that these "globs" of gelatin-like substance, which form readily, move accumulated sand out of the system. Revenaugh explained that psyllium works differently than bran, another laxative. In fact, more of the horses in the study had been fed bran prior to the study than not.

According to Revenaugh, 63% of the horses showed a "marked decrease" in intestinal sand seen radiographically after one month, and 91% improved after two months of psyllium treatment. The statistics didn't change significantly during the third month, other than virtually cleaning out the sand. Findings suggested that most horses in the study cleared virtually all abdominal sand after three months of psyllium therapy. Most horses' initial symptoms were resolved long before sand was completely eliminated, suggesting there's a threshold of sand accumulation before clinical signs appear.

It was recommended that the 9% of study horses which did not respond to therapy be kept away from sand completely. Revenaugh said he thought those animals were ingesting sand at the same rate it was eliminated. In fact, one horse ate sand so ravenously that sand volume actually increased during the study. After hospitalization and aggressive psyllium treatment with a nasogastric tube, virtually no sand was detectable clinically or radiographically in four days.

However, a study presented at the 1998 American Association of Equine Practitioners Annual Convention found that psyllium was ineffective for normal ponies which had sand surgically placed in their cecum. They reported that 70% of the sand was passed whether the ponies were treated or not.

While the studies had different outcomes, both recommended limiting access to sand to prevent ingestion.

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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