Failure of Psyllium Mucilloid to Hasten Evacuation of Sand From the Equine Large Intestine

Objective —To examine the efficacy of psyllium mucilloid in evacuating sand from the equine large intestine. Animals —12 clinically healthy pony geldings. Procedure—Twelve ponies were assigned to 2 groups of six each. One group was treated with psyllium and the second was a control group. All ponies had an exploratory celiotomy and 10 g/kg body weight of sand was placed into the cecum. Ponies were fed a grain mixture alone at 1 g/kg (controls), a grain mixture plus psyllium pellets, each at 1 g/kg body weight (3 ponies), or fed a grain mixture and given psyllium powder by nasogastric tube at 1 g/kg body weight divided into two daily doses in 3 L of water (3 ponies). Radiographs were taken on days 1 (3 per group), 5 (all ponies), and 11 (3 per group) to monitor sand transit through the large intestine. Ponies were euthanatized 11 days after surgery. Sand was collected from the contents of the cecum, ventral colon, dorsal colon, and small colon. Dry weight of the recovered sand was compared between the two treatment groups as a percentage of the dry weight of sand placed in the cecum. Results —No significant differences were detected in the mean percentage of sand recovered between the two treatment groups ( P < .05), with 39.2% recovered in ponies treated with psyllium and 27.4% recovered in control ponies. Clinical Relevance —Psyllium mucilloid had no apparent effect on sand evacuation from the equine large intestine. When intake of sand is prevented, the equine large intestine can reduce and possibly eliminate its sand burden.