Basically, there are two ways to prevent sand colic:
1) Making sure your horse doesn’t ingest sand;
2) Making sure sand is ‘flushed’ from the horse’s bowel regularly.
Minimizing sand intake
Your horse ingests sand when it grazes a meadow with short grass or is kept in a sandy or muddy paddock. Sand can also be ingested when hay is dusty or sandy, or when your horse eats its feed off the bare ground. Please note that mud, clay and other soil types can also cause sand colic!
This means you have to be careful when keeping your horse in a grazed-down meadow or paddock! Sand intake can be prevented by using a grazing mask or a special sand mask (soon to be available). Please make sure your horse does not wear a completely closed mask for prolonged periods. Horses need regular meals and should not be fasting for more than a few hours. Otherwise this may cause them colic! Never use a watertight mask, as the horse always needs to be able to drink.
Pay close attention to your feed and hay. Is it dusty or does it contain sand or clay particles? Be alert and prevent sand intake with feed. Also make sure your horse does not eat from the barren ground. Tiles, rubber matting or sturdy feed boxes (that cannot be overturned) are ideal.
A small minority of horses can be considered ‘sand junkies’. They eat sand by the mouthful. In young horses, this can be a phase that they grow out of. In older horses it is wise to check the horse’s blood for any mineral deficiencies that may be present. Sometimes – unfortunately – this sand eating is a grazing reflex or learned behavior (like stable vices such as weaving or cribbing).
Sand colic is generally more prevalent during autumn and winter. Please pay extra attention during this time!
Maximising sand excretion
To remove sand from your horse’s bowels, it is wise to regularly give your horse a psyllium treatment. Psyllium contains mucous components and can absorb a lot of water, causing it to increase up to five times in volume. Thus, a sticky pulp is formed in the horse’s bowels. The sand is transported out with the manure. Psyllium also seems to have a positive effect on the intestinal flora.
Psyllium is best given dry over the horse feed. Make sure your horse has access to unlimited clean water when you provide psyllium.
To prevent sand colic, the general advice is to give your horse 100 to 200 grams (3,5 to 7 oz) of psyllium over the course of 5 to 7 days, once a month at the most, during the time that the horse is at risk of ingesting sand. It is always a good idea to check your horse’s particular needs with a vet.
Linseed is also used instead of psyllium. It has a comparable function, but needs to be boiled before use. As the price of linseed is comparable to that of psyllium (at least it is in Europe), most people opt for the easy way and use psyllium.