UNDERSTANDING COLIC: PREVENTION FROM A NUTRITION PRESPECTIVE

By Kentucky Equine Research

Multiple causes, multiple symptoms, colic in horses is a broad topic! Colic is a catch-all term to describe abdominal discomfort from any cause – from abrupt dietary changes, too much grain, too much grass, not enough water, sand, etc causing twists, blockage, gas, ulcers, disease…the list goes on. Suffice it to say that, for almost every metre of the horse’s long and complex gastrointestinal system, there’s a factor that can throw normal digestive function into serious disarray. The usual result: colic, the most common equine ailment and the subject of many stressful calls from horse owners to veterinarians.

Signs of colic include pawing, kicking at the belly, looking at or nipping the flanks, rolling, sweating, or straining as if to pass urine or feces. However, sometimes symptoms are less obvious – your horse may appear flat, tired or less engaged than usual. This is because colic pain may be mild or severe, constant or intermittent. If any of these signs are noticed or your horse is just acting odd, the best plan is to call a veterinarian immediately.

“Waiting it out” to see if the horse recovers on its own is almost always a bad decision, as there is no way for an owner to determine in the beginning stages how colic will progress. With early intervention by a veterinarian, the cause can usually be determined and proper treatment can be started.

A Complex Digestive System

Colic can involve any area of the digestive tract, which is a long and complex organ (https://ker.com/equinews/feeding-horses-effects-meals-equine-gastrointestinal-tract). The large intestine accounts for about half of colic cases, with the small intestine and stomach contributing 35% and 12% of colics reported respectively. While colic can result from a number of factors, feeding practices are among the most common causes and are probably the easiest for an owner to control. Consideration should be given to overall feed management as well as the forage and concentrate portions of the diet.

Fundamentals of Forage

The horse’s digestive system is designed to process a steady supply of forage. Pasture and hay form the bases of the basic equine diet, however horses can get into trouble if they are offered too little, too much, or the wrong kind of forage.

Horses in training are sometimes given limited forage, often much less than the daily 1.5% of body weight that is recommended. This practice results in a stomach that is frequently empty, a situation that may lead to gastric ulceration. Too much forage, especially in the form of fresh grass, might cause colic or other metabolic problems. In spring and autumn, lush grass provides a high carbohydrate level that may exceed the digestive capability of the intestinal tract. Carbohydrate levels are also high in some types of hay.

Horses on overgrazed or poor-quality pasture may forage on weeds, while those that eat their bedding can  risk impaction, a blockage of the digestive tract with resultant pressure, pain, and the possibility of tissue damage.

Wetter is Better

Sufficient water intake is essential for digestion and the smooth passage of ingested material through the gastrointestinal system. Limiting the horse’s access to fresh, clean water for even a few hours greatly increases the risk of colic, as dehydration can lead to impacted food masses that block the intestine. Ways to improve hydration can be found here: https://ker.com/equinews/reducing-risk-colic-winter

Grain, A Mixed Blessing

The demands of training and performance call for more calories than can easily be supplied by an all-forage diet. Many owners rely on cereal grain-based to provide energy in the diet, however these need to be fed with caution – unprocessed cereal grains (with the exception of oats) can risk digestive upset, and large amounts of grain per meal are also risky.

Studies indicate grain feeding at 3-5kg per day increased the odds of colic 4.8 times over horses given no grain, and the risk rose to 6.3 times for horses eating more than 5kg per day, according to an article by Kentucky Equine Research president Joe Pagan. His recommendation is to divide a horse’s daily grain ration into several small feedings of no more than 2.5kg each to avoid stressing the digestive tract. More info on meal size foun here: https://ker.com/equinews/keep-concentrate-meals-small-horses

Make Changes Slowly

Avoiding sudden changes in any aspect of feeding is one of the most important things for horse owners to remember. With any change, the microbiome that aids digestion must be allowed to adapt to the new feed. Once a feeding schedule (products, amount, and time of feeding) is established, it should be followed with as little variation as possible.

Studies have shown an increased risk of colic when even small changes are made to what a horse eats. To avoid problems, carry out any changes in the type of feed or hay gradually over a period of five to ten days. Begin by mixing a handful of new feed into the old ration, increasing the new product slightly every day until the switch is made. A new type or batch of hay should be introduced the same way, beginning by offering a small amount of new hay with several flakes of old hay and then gradually blending larger amounts of new hay into the diet.

Changes in the amount of feed, hay, or grazing time should be made little by little as well. Suddenly doubling a horse’s feed to help him gain weight is asking for trouble. Likewise, bringing a pasture-kept horse into a stable 24 hours a day or moving a stabled horse onto free-choice pasture can easily result in digestive problems. Begin with an hour or two per day of the new management, increasing by small increments. As a safeguard, offer extra hay in the box before turnout time so the horse will not enter the pasture with an empty stomach.

If you own or manage horses for any length of time, sooner or later you’re almost guaranteed to encounter colic. Attention to proper feed management can minimise the frequency of problems, and rapid veterinary intervention can often put your horse back on the road to health.