A horse is ingesting too much sand in case more goes in than comes out. Of course, this is difficult to keep track of. You can assess how much sand is excreted, that at least tells you something. Of course, it is a good thing when your horse gets rid of sand in the natural way. But if too much sand is present in its manure, this is a sign that the horse is eating too much sand.
Testing manure for sand
You can test your horse’s manure by putting five balls of manure in a transparent plastic bag with some water. Squeeze the balls until they fall apart (when they are already in the bag so you don’t get your hands dirty). Hang the bag from a rope or something for about an hour. When the ‘soup’ has settled, the sand will have sunk to the bottom of the bag.
When you have them available, you can also use those plastic gloves that vets use. The sand will sink into the fingers of the glove. You could also use a bucket and pour the manure slowly from it after it has settled. The sand should then remain on the bottom of the bucket.
A few grains of sand in five balls of manure are not a problem. If a teaspoon or more can be found, it is time to take action.
Use a rectangular ziplock bag. You can hang this at an angle, with one corner pointing downward. The sand will accumulate in this lowest corner, and will be easy to see.
Always do the test on several days in a row. If you don’t find sand, but don’t trust the outcome, feed your horse psyllium for a week and test the manure every day. After about four or five days the sand should be excreted.
If you really want to know exactly how much sand is present in your horse’s bowels, a powerful X-ray is the only option. Not all vets have this type of equipment available, you may have to travel to a specialised clinic. Sonography generally does not show sand compactions very well.