Sand Colic in Horses
by Robert N Oglesby DVM

Introduction
Sand accumulation in the bowel of the horse is a common occurrence for those on sandy soils. The problem is exacerbated by feeding on the ground and overgrazing pastures. This article consists of a number of posts to the forum over the years and addresses diagnosis and treatment.

Clinical Signs
Typical signs can be diarrhea, reoccuring colic, impaction, and death.

Diagnosis
Classically several fecal balls where put in a jar or water and swirled until all the sand had come out. If more than several tablespoons are present along with typical clinical signs sand colitis is dianosed.
Recently it has been stated that if normal motility is present, clinically significant amounts of sand can be auscultated just behind (caudal) the xiphoid process. This is on the ventral midline just behind the ribs last costo-condral junction. The sand makes a grating, raspy noise. If the noise is not present sand is unlikely to be the cause of clinical signs. On the other hand the sand is auscultable before signs develop. If motility is slow or nonexsistant the sand is difficult to detect. In sandy areas this should listened for during yearly vaccine updates. If sound is present, psyllium should be instituted.

Treatment
If the horse is stable conservative treatment can be attempted. Banamine can be used for pain relief but the only known successful treatment is removal from all sources of sand. Psyillium can be used in conjuction with removal from sand but research continues to show that horses on psyllium clear the sand no faster than those not on it. Recent research shows a horse clears about 15% of the sand in his bowels daily, removing about 2/3 to 3/4 of all the sand in two weeks.
If a horse has worsening symptoms and is nonresponsive to pain relief surgery can be attempted but prognois is only fair.


Prevention
The only reliable prevention is keeping horses off of sand. Again, horses do not appear to clear sand more rapidly with psyllium added to the diet so do not rely on this alone.
In areas with sandy soils it is near impossible to prevent them from grazing on it. Helpful adjuncts are:

Do not allow overgrazing, making sure the grass stays at least 4 inches in length. When the grass is short move the horses to nonsandy paddocks, and feed hay, until they recover.
Do not put feed on the ground.
Provide lots of good quality hay up off the ground. Using mangers with trays underneath to catch the falling hay, or on top of a nonsandy surface, is ideal.
Monitor fecal sand and have the bowel auscultated for sound of sand accumulation.

Surgical treatment of sand colic. Results in 40 horses.
Vet Surg 1989 Jan-Feb;18(1):48-51
Ragle CA, Meagher DM, Lacroix CA, Honnas CM
Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis 95616.
A retrospective study of 40 horses that underwent surgical treatment for sand colic was performed. Three horses were euthanatized and one died during surgery. Of the 36 horses that recovered from anesthesia, five died before discharge from the hospital and seven died after discharge. Twenty-four horses survived at least 12 months. Sand impaction of the right dorsal colon was present in 26 horses. In addition to sand impaction, 10 horses also had colonic displacement or volvulus.

Failure of psyllium mucilloid to hasten evaluation of sand from the equine large intestine.
Vet Surg 1998 Nov-Dec;27(6):547-54
Hammock PD, Freeman DE, Baker GJ
Department of Veterinary Clinical Medicine, University of Illinois, College of Veterinary Medicine, Urbana 61802, USA.
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.