In acute cases of (suspected) sand colic you ALWAYS call your vet!
Please do not waste any valuable time by trying to play doctor to your horse. The information below is only intended to give you some background. Time is of the essence in acute cases!
Sand colic is generally treated (by veterinarians) by giving the horse paraffin oil and psyllium seeds or husks. These two combined help to bring out the sand in the manure, via the natural transport route. If this method proves insufficient, an operation may be needed.
Psyllium seeds are the basis of almost all products against sand entheropathy. The small black seeds can be used whole, or milled. The milled husks have a tan color. Psyllium comes under a variety of commercial names. The seeds come from a plant called Indian Psyllum, or Plantago Ovata in Latin.
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.
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.
Paraffin is a mineral oil product, that is not absorbed by animal cells or tissue. Vets often give paraffin directly into the horse’s stomach, using a plastic tube. It acts as a lubricant, slicking both manure and sand, which are then excreted more easily. Paraffin is used to treat sand colic, but also in case of obstipation and bowel obstruction (caused by worms for instance). If your horse eats well, you can also mix paraffin (in small amounts) with horse pellets or muesli. The amounts of oil you can give are smaller though.
Dosages and use
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.
In acute cases of sand colic a lot more psyllium is often required, combined with plenty of paraffin. That’s why you always need to contact your vet when the horse shows signs of colic.
In cases of sand colic vets will often give the horse a liter or two (up to half a gallon) of paraffin, using a tube to the stomach. Mixed through horse feed you can only give a small portion of that amount. The latter option could be useful for horses that you suspect have ingested sand, but that show no signs of colic (yet). Again: in cases of colic, always call your vet!