Preventing Colic In Equines Difficult with No Clear (and Many) Cause

Findings of interest were that horses that were fed high-quality fiber, such as from hay or pasture grazing, were less likely to develop colic. Also, horses with access to multiple pastures or who were pastured at all times showed a reduced risk. Those who consumed less than 5.5 pounds of grain concentrate daily were less likely to develop colic, while those who received most of their caloric intake from grain, rather than fiber, were at higher risk.
Traditionally, many horse owners have blamed pellet feed for colic. Research has shown, however, no apparent difference in the risk of colic between horses fed sweet feed and those fed pellets.

One study did show an increased risk of colic in horses whose owners top-dressed their rations with corn, although it was not shown that corn causes colic. Top-dressing can tip the balance of energy intake toward grain and away from fiber, which creates a nutritional imbalance. However, if quality corn is mixed into a balanced diet with balanced nutrition, it has not been shown to cause colic, provided that the horse still gets most of its caloric intake from fiber.

Feed changes where shown to greatly increase the risk of colic. Two studies proved that horses with high colic risk had recently had a feed change, as did horses from farms that changed feed more than six times yearly. Researchers theorize that these feed changes affect the horse’s intestinal bacteria, resulting in increased colic risk.

Water is also extremely important in determining the risk of colic. Horses who spent as little as one to two hours exercising in a paddock without access to water showed a greatly increased risk of developing colic.

The breed of horse has also been thought to affect the risk of colic. While two studies showed that Arabian horses were more likely to develop colic, researchers are not sure if their data was accurate. Some feel that Arabian horses reacts more visibly to abdominal pain, or that Arabian horse owners watch their horses more carefully and therefore spot and report colic cases more.

Another study indicated that crossbred horses had a lower colic risk than purebreds. However, this study might also be inaccurate because of the usual use of crossbred horses. More research needs to be done before colic risk can accurately be ascribed to certain breeds.

Use and ownership also play a role in colic risk. Horses that are cared for by someone other than their owner were at increased risk. Those used for riding lessons had a lower risk than horses training for races.

Changes in a horse’s exercise or stabling pattern can increase colic risk as well. Horses who experience a decrease in the amount of exercise and an increase in the time spent in the stall—such as horses experience during the winter in cold climates—are at higher risk of developing a bowel impaction. One theory is that the reduction in physical activity results in decreased intestinal fluids. The lack of lubrication can create a bowel blockage.

One of the more important risk factors is whether a horse has had colic before. Once a horse has colic, it is more likely to develop it again in the future. Also, if a horse is being treated for conditions other than colic, it has a risk of developing colic as a secondary condition.

Many owners wonder if age and parasites affect the risk of colic. One study shows that horses between the ages of two and ten are more likely to become colicky than horses older than ten, although other studies were inconclusive. Parasites, while they do increase the risk of colic, are no longer considered to be its primary cause. No reduction in colic risk could be found based on deworming or fecal egg count. (However, deworming is important to maintaining the horse’s health for other reasons and should not be discontinued based on this study.)

Future studies are planned to address the correlation between mold toxins and colic. A current study at North Carolina State University is underway to evaluate whether mold toxins in grain or hay might affect the risk of colic. No study has yet found that any specific mold toxin is definitively the cause of a colic diagnosis, however.

While most horse owners don’t have adequate pastures available to keep their horses on an entirely grass diet, there may be ways to alter the grain diet and reduce the colic risk. New studies are showing that supplementing a horse’s diet with enzymes, digestive bacteria, yeast cultures or ammonia scavengers can modify the intestinal environment and improve the horse’s digestion. (Triple Crown feeds offer these supplements.)

Consistency and avoiding diet changes has been proven to reduce colic risk, as has increasing the fiber intake. However, the most inconsistent thing horses are fed is hay. Perhaps the use of more consistent forages could reduce colic risk. Some feel that mixing a consistent, quality hay chop into a horse’s grain ration could lower its colic risk, although this has not been specifically studied.

Regardless of breed, all horse owners should support research studies on the causes of colic. Becoming involved in breed associations, horse clubs, and local universities can help to raise needed funding for these expensive, vital studies. Quality studies are owners’ best hope of lessening colic’s impact on our horses.