Psyllium, Magnesium Sulfate's Sand Clearing Ability Studied
A simple combination of psyllium and magnesium sulfate appears to be both safe and effective for helping horses evacuate sand from their colons, an international group of researchers recently reported.

“The accumulation of sand in the large colon of horses is relatively common in some areas of the world,” said lead researcher Kati Niinistö, DVM, Dipl. ECEIM, director of the University of Helsinki, Finland, Equine Hospital. “Affected horses are at risk of colicking; chronic, intermittent diarrhea; and weight loss.”

In Finland, veterinarians frequently see sand colic in pleasure horses and ponies in the fall. Niinistö said sand impactions are to blame for 75% of the colics her hospital sees.

Although a variety of treatments exist, researchers haven’t been able to scientifically confirm any of their efficacies for clearing sand and minimizing disease in horses. So, Niinistö and colleagues conducted a prospective randomized trial designed to compare the effect of administering magnesium sulfate, psyllium, or a combination of both (each at a rate of 1 g/kg body weight) on clearing large (i.e., larger than 5 cm x 15 cm or 75 cm2) naturally acquired sand accumulations from horses’ large colons. They administered all treatments via nasogastric tube daily for four days.

On the fourth day, the researchers took radiographs of the horses’ abdomens to measure the area of remaining sand; they considered a case resolved if the area had decreased by at least 33.3%.

The team found that nine of the 12 horses treated with the combination of psyllium and magnesium sulfate successfully evacuated sand from their colons. By contrast, only three of the 12 horses treated with psyllium alone and two of the 10 treated with magnesium sulfate alone evacuated sand from their colons.

“These findings demonstrate that large accumulations of sand in the large colon of horses can safely be treated medically,” Niinistö concluded. “Clinicians should be aware, however, that healthy horses with normal magnesium levels in the blood were included in this study. Some horses, those with renal disease for example, may be susceptible to magnesium toxicosis and caution should be used.”

The study, “Comparison of the effect of enteral psyllium, magnesium sulphate and their combination for removal of sand from the large colon of horses,” was published in The Veterinary Journal.