Horses in some management conditions are susceptible to sand ingestion; here's how to avoid sand buildup and resulting complications such as colic.

Rarely do we see our horses lapping up sand like it's some rare commodity. But inevitably horses end up with burdens of sand in their intestinal tracts from grazing sandy pastures or eating off the ground. In areas with sandy soil, horses might pull up grass and ingest sand clinging to roots. Horses fed on the ground might eat sand as they clean up the last wisps of hay or kernels of grain. Even if fed in buckets or feed racks, horses might eat spilled feed from the ground. Intestines can be obstructed with sand, causing colic.

Sand moves through the digestive tract with food and is passed in manure, but it can irritate the intestinal lining along the way. This irritation can lead to diarrhea, weight loss, and colic. If sand accumulates, it weighs down the intestine and can impair motility, hindering proper digestion and function. Reduction in motility hinders passage of sand and leads to more accumulation, and in some cases the slowdown and accumulation cause a blockage.

David Freeman, MVB, MRCVS, PhD, professor and interim chair of the Department of Large Animal Clinical Sciences and chief of staff of the Alec P. and Louise H. Courtelis Equine Hospital at the University of Florida, says sand impaction is a well-recognized cause of colic. "Why it becomes a clinical problem in some horses– while others seem to carry fairly heavy sand burdens without a problem–is still not understood," he says.

"When sand becomes a problem, it is usually in t