There are many causes of colic of which sand is just one. It occurs when ingested sand accumulates in the large intestine. It can cause altered droppings – sometimes loose, other times small and hard. If your horse is ingesting sand, some if it will come out in the droppings. A handful swilled in a bucket of water will cause the sand to sink to the bottom. Horses ingest sand when they are grazing close to the soil and it is more likely on sandy soils, but many other soils contain a proportion of sand and these coarser, heavier grains sink to the lower parts of the large colon. Your vet can help with diagnosis as there is a distinct line across the top of the sand which can show up on an ultrasound, for instance, or they may be able to hear the grains of sand with a stethoscope.
Sand colic is a serious matter and can cause the horse to die or need to be put to sleep. It causes an impaction. Surgery may be possible but very expensive. It is better to adopt a strategy to avoid sand accumulating.
• Avoid grazing very close to the soil;
• Be aware of your soil type and any potential risk;
• Ensure the horse is on enough bulk/forage to keep the gut’s contents moving well;
• Feed linseed daily;
• Follow the advised protocol if using psyllium husk;
• Ensure free access to a plain salt lick;
• Offer hay in the field in suitable receptacles rather than on the ground;
• Long term use of organic matter (well-rotted manure) to provide more of a layer between the soil and the grass;
• When strip grazing, close off behind the horse to prevent access to very short grass;
• Reduce intensity of grazing to allow a layer of thatch to form at the base of the grass.
Very often, good doers are kept on “starvation paddocks” which are grazed almost to nothing and the horse will pull up roots covered in soil as they try to graze. This increases the risk of sand colic. And some horses seem to choose to eat soil or sand.
Ensure the horse has adequate forage. Lower calorie alternatives to hay can also be used for good doers, such as Organic Lucie Stalks. Well-soaked PuraBeet increases bulk, aids hydration and can help movement of ingestate through the gut. Daily feeding of linseed has been demonstrated to aid removal of sand (S. Sarkijarvi et al, Finland, EAAP 128, 2010). Instant Linseed fed at up to 65g/100kg could make a useful contribution to maintaining a healthy gut for susceptible horses. An economical mash feed for an occasional boost to sand removal could be a bucket of soaked PuraBeet with a mugful of Instant Linseed fed in place of the usual feeds one day a week or for a few consecutive days a month. Use proportionately less for ponies as these amounts are for an average 5-600kg horse. If you think sand could be causing your horse discomfort, you will need to consult your vet. For further feeding advice, contact the Simple System Feed Line.