Sand accumulation in the colon of horses was effectively treated using a combination of psyllium and magnesium sulphate, researchers report.
Psyllium is a type of fiber commonly used as a gentle, bulk-forming laxative which absorbs water. It can pass through the digestive system without being completely dissolved. Magnesiium sulphate, also known as Epsom salts, also has laxative properties.
Sand accumulation in the large colon of horses has been reported worldwide.
The condition is commonly treated medically but randomised controlled clinical trials on horses are scarce, noted University of Helsinki researchers Kati Niinistö, Mirja Ruohoniemi, Francesca Freccero and Marja Raekallio.
The study team, reporting in The Veterinary Journal, have described a study involved 40 horses with sand accumulation.
All had been admitted to hospital as clinical cases with suspected sand-related problems or had been referred from other clinics because of sand accumulation.
They were x-rayed and those assessed as having more than 100 square centimeters of sand in the large-colon imaging were offered the chance to take part in the study.
Horses were not used if they were under 300kg or if they had shown clinical signs of acute colic. Horses were also disqualified if they had already been given laxatives for the problem.
The control group of 20 horses went untreated. The other 20 were treated with 1 gram per kilogram of body-weight of psyllium and 1 gram per kilogram of body-weight of magnesium sulphate.
The treatment was given once daily by nasogastric tube for four days.
Both study groups had no access to soil during the study period. Water and timothy hay were available as they desired. However, hay was withheld at the discretion of the treating veterinarian when clinical signs of abdominal discomfort were noticed.
During the four days, 75% of the treated horses lost their sand accumulation. An additional horse did not clear its sand accumulation, but the area had decreased markedly in size. It was sent home with a recommendation to receive more psyllium by mouth.
Without medical treatment, 20% of the control horses underwent spontaneous resolution of the colon sand accumulation within the four days.
All horses tolerated the treatment well, the study team reported, and no adverse effects were observed.
Some treated horses developed mild softening of the faeces, but no diarhoea was detected.
Four horses required a single dose of flunixin meglumine, a non-steroidal anti-inflammatory painkilling drug, during the study – one because of fever and the other three to ease mild abdominal discomfort.
Three of the four horses that received flunixin meglumine went on to clear the sand within four days of treatment.
The four horses in the treatment group that did not clear their sand had the protocol continued for another three days. The amount of sand diminished in all of them, and all accumulations fragmented into smaller accumulations during the continued treatment.
However, none of these horses had completely cleared the sand by day seven, although it had decreased by at least 50 percent.
“The treated horses cleared their sand accumulations significantly better than horses in the control group, as indicated by the reduction in the relative size of the area of sand, based on the radiographs and by the number of horses with resolved sand accumulations on day,” the study team wrote.
Noting that 20 percent of the control group had cleared their sand accumulation without specific treatment (other than no access to soil), the study team said the capacity of an individual horse to do so could not be predicted from the radiographs.
Investigation of the treatment of sand accumulations in the equine large colon with psyllium and magnesium sulphate
K.E.Niinistö, M.O.Ruohoniemi, F.Freccero, M.R.Raekallio
Vet J. (2018) 238:22-26 doi:10.1016/j.tvjl.2018.06.005