5. Get sand out of the ration.
Sand is one of those substances that, in individual pieces, is inconsequential, but cumulatively, can be disastrous to the horse's inner workings. Horses may ingest sand along with grain or hay that is fed directly from the ground. They may also swallow sand particles while closely grazing pastures that grow on sandy soil. The risk for horses is greatest in areas where sand is omnipresent, such as coastal states and desert regions.
Because it is heavier than other swallowed materials, sand settles in the horse's large intestine and stays there. "Sand doesn't get trapped until it reaches the large intestine because it's a pretty smooth trail up until then," says Crandell. "But the large intestine has folds and pockets where sand particles can get lodged. The sand irritates the lining, much like the effect of rubbing a piece of sandpaper. Large amounts can cause impaction or blockage."
One way to reduce your horse's sand intake is to never feed him from the bare ground. Offer grain in an untippable bucket or tub and hay from a rack or net with a catch pan or pad of nonearthen material, such as wood, metal, concrete or rubber matting. Another measure is to limit or reduce the number of horses sharing a field or paddock. Overstocking is a sure way to ruin the grass cover and force horses to grub in the dirt for their bits of roughage--and sand.
If possible, keep horses out of pastures and paddocks that have developed bare spots due to overgrazing or drought until new turf is reestablished to cover the earth. Feeding supplemental hay in these stressed pastures also helps reduce the amount of close grazing the horses practice.
Control Parasites, Control Damage
While turnout can go a long way in aiding your horse's digestion, exposure to parasites can undermine that effort. Dozens of species of parasitic worms, some as long as a piece of spaghetti and others, invisible to the naked eye, may reside in your horse's gut to feed, grow and reproduce. Each parasitic species gravitates to a different part of the body; gut dwellers often choose the large intestine, because it provides the eggs with easy access to the outside environment, where part of their life cycle plays out.
Horses typically ingest parasites orally by grazing near manure in paddocks or fields. The parasites, in the larval stage, travel specific pathways through the internal organs until they arrive in the gastrointestinal tract. There they mature and reproduce. The eggs laid in the digestive tract are passed outside in manure and once outside, the larvae emerge and continue to grow until they are ingested by grazing horses.
Parasites cause colic in several ways. Small strongyle larvae, for example, burrow into the lining of the cecum and colon, where they can live for six weeks to 2 1/2 years. When dormant in a fibrous cyst, these larvae cause little distress to the horse, but when they emerge from these enclosed capsules, they release secretory and excretory material that irritates the gut. The larvae do further damage as they burrow out of the intestine to breed and lay eggs. Large strongyles are often responsible for the more severe colic attacks. Strongylus vulgaris, one of the most harmful parasites to the horse, invades the main arterial supply of the gut and can constrict or plug up blood vessels, cutting off blood supply. When the larvae break out of the arterial walls, they enter the bloodstream which can carry them to any part of the small or large intestine. Those that go astray can damage other organs. Eliminating parasitism is an all-around boon to your horse's health.
6. Remove manure from paddocks and fields.
Since horses ingest parasites by grazing near manure, the best way to avoid this exposure is to remove the piles of manure. Craig Reinemeyer, DVM, PhD, at East Tennessee Clinical Research, Inc. in Knoxville, suggests removing manure in fields twice weekly. An industrial-strength vacuum, like those used to suck up leaves on a golf course or clean parking areas, can also pick up manure. Clear droppings from smaller paddocks with the same equipment you use when cleaning stalls.
Though it's always a good idea to keep stalls clean and free of muck, removing manure from fields and paddocks does more to reduce your horse's exposure to parasites, since larvae thrive in certain weather conditions and moisture levels found outdoors. "For strongyles, it's fairly essential that the eggs drop out in a pasture habitat or around vegetation," says Reinemeyer. "Their micro habitat is in the grass. Stalls are either too dry, or their source of moisture there is urine and ammonia, and that has a bad effect on larvae."
If you have an abundance of acreage and intend to rest a field to allow the parasites to die off, plan on waiting for a while. According to Reinemeyer, parasitic larvae are hardy and resistant, particularly to cold weather, and easily can survive for six to seven months outside a host. Ascarid eggs can survive in a pasture for years.
"If you have a contaminated field in the fall, the level of contamination won't drop until late spring or early summer," says Reinemeyer. "But if you rest the field from spring through the summer, it will become fairly clean. Freezing doesn't bother them, but temperatures about 85 degrees or more are not conducive to larval survival."