Most horses will have small amounts of sand in their intestines. Horses pick this up as they feed and it won't usually prove to be a problem. However, too much sand can lead to many health issues including a case of colic. Horses will ingest sand if they feed on sandy soils. Clay and silt soils don't normally accumulate in horses as the particles are extremely fine, but sand is a different matter. Sand grains are much larger and so tend to settle in the intestine rather than simply passing through. Over time, large quantities may build up and this could lead to diarrhoea, weight loss, colic and life-threatening obstruction.
Serious Health Issues
The sheer weight of the sand accumulation can exert enough pressure to restrict the blood flow to the colon wall. Sand is also abrasive and so will impact the lining of the intestine. A damaged colon will not effectively absorb nutrients or water, hence the diarrhoea. If the sand combines with feed, an obstruction can form and, to make matters worse, any damage in the intestine reduces the digestive function and leads to distension. This then encourages more sand to settle. An unfortunate chain reaction is created and any toxins produced could be absorbed and lead to other issues including laminitis. The colon can further displace or twist as time passes, resulting in an obstruction which is life-threatening and only solvable via immediate surgical intervention. In the worst-case scenario, the colon wall may become so damaged that it ruptures, propelling manure into the abdomen and causing rapid death.
The Symptoms of Sand Accumulation
Diarrhoea and colic are the most common symptoms of sand accumulation in horses. Affected horses may also show signs of depression, be reluctant to eat and suffer from weight loss and fever. General restlessness and apparent discomfort indicates colic. Horses may lie down, kick at their belly, sweat or roll. A horse with colic could exhibit any combination of these symptoms. It is important to seek the advice of a vet if your horse is obviously uncomfortable.
Searching for Sand
Your vet may be able to detect the presence of sand during a physical examination but an x-ray may be required. A powerful x-ray generator is necessary and this equipment will not be present at all veterinary hospitals. Ultrasound can also be used to detect the presence of sand.
Treatment
It is possible to move sand accumulations with high doses of psyllium (often given by stomach tube). It may take weeks for the intestine to clear completely. If the psyllium proves to be ineffective, surgery could be required.
Prevention
It is important to know what type of soil your horse feeds on. If sandy soil is present, provide feed on mats or in feeders. Alternatively, create a special feeding area which you can keep clear of sand. If good husbandry doesn't do the trick, doses of psyllium may be required on an ongoing basis. The psyllium is a plant extract which forms a gel and binds sand to it in the intestine.