What is it?
Sand colic is caused by an impaction of sand that settles within the large intestine. It is often caused by horses grazing directly on the ground and ingesting sand along with their feed.
What to look for?
Clinical signs of sand impactions are very similar to other impaction-type colics. Your horse may not be interested in eating, have smaller than normal fecal balls or have reduced output, and mild abdominal pain, but often he or she will have a normal temperature, pulse and respiratory rate. Diarrhea is often seen with sand colic and can be a great diagnostic indicator. In some cases we many even see sand or dirt in the fecal balls.
How do we diagnose it?
As stated above, if the horse has diarrhea and no temperature, we often treat the colic as a sand colic. Rectal palpation can also help with diagnosis, though the impaction may not always be felt. Placing manure into a rectal sleeve and “floating” it with water is a good way to detect sand in the manure, as the sand will sink down to the fingertips of the glove. You can also do this on your own by taking a few fresh manure balls and placing them in a plastic Ziploc bag and adding water. Then check to see how much sand settles out in the corner of the bag. When performing the physical exam, listening to the abdomen at midline (just in front of the belly button) with a stethoscope, may reveal a sound similar to waves on a beach (I know this sounds funny, but it is absolutely true).
How can we treat it?
Most sand colics can be treated with medical management. As with many other colics, passing a nasogastric tube and pumping the horse with water and mineral oil can be a great treatment option. Depending on the severity of the impaction, this procedure may need to be repeated. Psyllium is a great treatment option as well, and comes in a powder or pelleted form. Psyllium lubricates and binds to the sand helping to relieve the obstruction.
How can we prevent it?
Unlike most other types of colic, sand impactions are avoidable if the right precautions are taken. Don’t feed on the ground – simply putting feed in tubs or feeding on rubber mats can be a huge help in the prevention of sand colic. If your horse is on pasture, do not allow overgrazing of the pasture. This increases the odds of your horse picking up sand as he or she grazes on the low grass. Lastly, prophylactic treatment with psyllium monthly can also prevent sand impactions. The proper dosage will be on the label, but 400g (usually 1-2 scoops depending on the brand) for a 1000lb horse for 7 days is an adequate treatment. Understandably we cannot prevent all horses from eating sand, but if we are diligent about our management and feeding practices we will be able to prevent a large number of horses getting sand colic.