A study was conducted to compare the effect of oral administration (via a nasogastric tube) of magnesium sulfate (MgSO4), psyllium mucilloid (psyllium), and a combination of the two to help remove large accumulations of sand in the large colon of adult horses.
Thirty-four (34) horses with naturally acquired sand accumulations (identified and measured with the use of abdominal radiographs) were randomly placed into one of three groups:
Psyllium - 12 horses
Magnesium sulfate - 10 horses
A combination of psyllium and magnesium sulfate - 12 horses
Treatments were administered once a day, via a nasogastric tube, for a total of four days. The horses were then radiographed again, and the area of sand was measured again. Of the twelve horses one the combination psyllium/magnesium sulfate therapy, nine had removed the sand from the colon and were considered to have resolved the sand accumulation. Only three of twelve horses in the psyllium group and two of ten in the magnesium sulfate group showed the same degree of resolution.
The researchers concluded that large accumulations of sand in the colon can be treated medically and that giving a combination of psyllium and magnesium sulfate was the most effective treatment.
Scientific Article: Niinisto, K. et al, “Comparison of the effects of enteral psyllium, magnesium sulphate and their combination for removal of sand from the large colon of horses.” Vet J 2014 Dec; 202(3): 608-11.
Companion Article: Oke, S. “Psyllium, Magnesium Sulfate’s Sand Clearing Ability Studied”. theHorse.com, Jan. 15, 2015, Article#35183.