Autumn prime time for sand colic in horses

R. Dean Meyer DVM
Lodi Veterinary Care
With summer far behind and once green pastures nibbled to the ground, horses may be at risk of accumulating sand in their digestive tracts - leading to a condition called "sand colic"

Lodi — This time of year, with the end of the growing season upon us, the pastures are getting short and eaten down. As the horses graze these areas, many of them are starting to accumulate sand in their digestive tracts. It is common in our practice to begin seeing “sand colic” cases from August through late fall, when we usually see a pretty hard frost.

A simple test to check and see if your horse is accumulating sand is to take a small amount of manure (5-6 fecal balls) from the top of a fresh manure pile. Put these fecal balls into a rectal sleeve and fill the sleeve with water. Manually break the manure apart; this will result in the sand settling into the tips of the rectal sleeve. More than ½ teaspoon of sand per 5-6 fecal balls is significant.

I recently had an interesting case involving sand. The horse had lost weight and was given a body condition score of 2 out of 10. The horse was lethargic, had diarrhea, but was not painful or showing signs of colic. On physical examination I found the heart rate to be 60 bpm, membranes were pink and moist, the temperature was normal and there were decreased sounds in the GI tract. I did a fecal exam and for the first time in 30 years of practice I pulled out a handful of sand, with no fecal material. The diagnosis was pretty clear!

As sand accumulates in the large intestine of a horse it will begin to act like sand paper, eroding the mucosa. Due to this irritation, water is not absorbed which will result in diarrhea. This is also why nutrients are not digested. I found it interesting that this horse was never painful. His body had adjusted to sand in the digestive tract. This was preventing absorption of nutrients and everything was passing in the diarrhea

I passed a nasal gastric tube and gave the horse, water, mineral oil, electrolytes, and Doctors Choice Daily Start Probiotic. This was repeated for two days. This treatment was followed by Doctors Choice Laxative (psyllium). I also instructed the owner to increase the number of feedings per day and add Rice Bran for extra winter weight. It was also fortunate that the owner had another, less sandy area he could move the horse to.

Once a horse has sand accumulation, psyllium is the only non-surgical way to get rid of it. There are many different psyllium products available on the market. Some studies have shown that the pelleted or granular form of psyllium does not work to rid horses of sand as well as a powdered form does. The feeding regime will vary depending upon the environment the horse is in. Ideally psyllium should be fed 5-7 days per month from April through November in our climate. This is because studies have shown horses kept continually on a psyllium product will have their digestive tracts learn to break down the product, thus making it non useful.

It has also recently been discovered that horses fed a probiotic in addition to the psyllium did a better job of clearing the sand. The probiotic provides a healthier environment in the digestive tract, aiding in the clearance of sand.

Grab some fecal balls and evaluate your horses if they are grazing on sandy soils. It is pretty reasonable to feed a psyllium and probiotic product in comparison to paying for a colic emergency call. To reduce the amount of sand ingested, you can also use rubber mats under feeders or feed in the stall on top of shavings or straw. Call your veterinarian if you have any concerns about the problems with sand in horses.