Nearly every horse owner at some point or another has seen a horse go through a colic episode.  This highly prevalent condition can have detrimental consequences and is the most common cause of death in adult horses if not managed quickly and appropriately.  Even though there are many causes of colic, poor nutritional management can initiate disturbance of the intestinal environment and eventually lead to colic.  Good nutrition is of absolute importance for overall health and function of the gastrointestinal tract.

Causes of colic

There are many known risk factors for colic but in most cases when a horse presents itself with colic, an exact cause is rarely identified during diagnosis. Colic comes in many shapes and forms, from worms, gas or “stones” (i.e. enteroliths) building up in parts of the intestinal tract to displacement or entire twists of the intestine itself.  Most result in moderate or severe symptoms of abdominal pain which are well known by most horse owners (e.g. pawing, looking or kicking at their belly, distension of the belly and rolling).

Why colic happens isn’t always clear but several studies have associated different nutrition-related risk factors with colic such as eating large amounts of grain and little forage, poor quality of forage, grazing on grass high in fructans, lack of water and in particular sudden changes in the diet.  Horses are also more prone to colic at times of stress. For example long transportation, changes in housing or activity, extreme weather, during foaling and weaning and many other situations that may cause some form of stress for the horse.

Tips for proper nutritional management to prevent colic episodes

  1. Forage

    Preferably forage should be available at all times since the digestive system of a horse is made to obtain most of its nutrients and energy from forage. This happens through microbial fermentation of fiber in the hindgut (i.e. cecum and colon) of the horse. Maintaining a normal microbial population is of vital importance for optimal gut health and absorption of nutrients. The normal population of these healthy fiber digesting microbes is easily disturbed when they do not receive enough forage or when large amounts of starch from grains and sweet feeds are fermented. This disturbance will decrease the capacity to digest fiber and lead to complications such as acidosis (i.e. to low pH), gas formation and potentially colic. Providing the horse with adequate amounts (min. 1.5% of body weight in forage per day) of forage is therefore essential.

    Research shows that horses on pasture are generally less likely to develop colic since grazing provides not only continuous amounts of fiber but also light exercise and allows for normal social behavior (if in a herd), all of which contributes to a happy, healthy horse.  However caution should be given to the quality of the pasture, as early spring and fall grass can be high in fructans, in particular on colder days.  Fermentation of large amounts of fructans can upset the hindgut environment in a similar manner as starch and cause colic or even laminitis.

    It is equally important to be aware of the quality of the hay when horses cannot be kept on pasture.  Always provide good quality, clean (i.e. no dust or mold) grass or legume hay according to your horse’s need.  Avoid giving large amounts of poor quality forage (e.g. straw, old hay,…) as this may cause impactions.

  2. Grain

    With increased physical demands, addition of concentrates to a horse’s diet is often necessary to meet energy requirements. However, the digestive system of the horse is not designed to handle large quantities of grain and therefore undigested starch will escape into the hindgut where it is easily fermented by microbes. It is not surprising that colic is in particular prevalent in performance horses, who generally receive large portions of concentrate a day.

    As mentioned previously, large amounts of starch fermentation is a considerable risk factor for colic because it causes a disturbance of the microbial environment thereby altering digestive processes.  Acidosis also reduces intestinal wall integrity allowing toxins to enter the bloodstream that may cause various problems.Grain digestion depends on factors such as grain type (e.g. corn vs oats vs barley), meal size and methods of feed processing.

    In particular the latter can have a large influence on the degree of digestion. For example puffing grains expands the starch granule making it much more accessible to digestive enzymes in the small intestine thereby reducing to chance of undigested starch to leak into the hindgut.  When feeding concentrates is necessary (e.g. sport horses), it is therefore important to choose a good quality, easily digestible feed (g. Cavalor® Perfomix, Cavalor® Endurix, Cavalor® Superforce) and always supply adequate amounts of forage throughout the day.

  3. Water

    Water is essential for optimal health and function of the gastrointestinal tract and absorption of nutrients. Dehydration is an important risk factor for colic, however it is commonly overlooked. It is therefore important that all horses have unlimited access to water at all times and that the water source is checked daily to ensure it is clean (e.g. free of bedding, feed or manure) as horses will stop drinking if the water is contaminated.  Although automatic waterers require less manual labor, having water buckets when horses are stabled will allow for better monitoring of how much the horse is drinking.

  4. Feeding strategies to avoid digestive upset

“Little and often” should be the main nutritional strategy for horses that are receiving considerable amounts of concentrate. Smaller, frequent boluses of starch are less likely to escape into the hindgut in comparison to a starch overload in one meal.  To support healthy gut function energy-rich concentrates can be mixed with low-starch/high-fiber feeds (g. Cavalor® FiberForce).

In any case, horses should always be fed sufficient amounts of good quality forage.  The better the quality of the forage, the less grain needs to be fed to meet nutritional requirements.

A safer option to meet energy requirements while reducing the amount of starch fed, is a diet with easily fermentable fiber (e.g. beet pulp, chopped alfalfa) or a higher fat content.  Fat can be incorporated into the concentrate pellets or top dressed as an oil (e.g. Cavalor® Oilmega).

The biggest risk factor for colic is probably sudden dietary changes (e.g. change of hay batch or type, change in concentrate, moving to a different pasture,…).  The equine digestive system does not tolerate drastic nutritional changes very well and these should therefore always be introduced gradually to avoid colic.

Changes in environment, transport and competitions are occasions during which many horses commonly colic.  This is most likely caused by a combination of stress and a change in normal feeding behavior.  Make sure to prepare your horses “physically and nutritionally” prior to competition season and always provide enough forage before and during transport.  Not only is forage important for maintaining a healthy gut, it also has a large water holding capacity (in particular legumes such as alfalfa) which is beneficial for rehydration in case the horse doesn’t drink enough under stress.  Try to keep feeding times similar to the horse’s normal routine and avoid dietary changes.

Monitor water intake closely to ensure your horse drinks enough. Be aware that a difference in water taste is a subtle but common reason for horses to refuse to drink.  If you know your horse doesn’t drink well in new places, bring water from home or mask the taste by adding flavors.  However, familiarize your horses to these flavors before going to competition!
Providing tasty, wet mashes, soaked forage or beet pulp are other options to get some water and nutrients in your horse when he’s not eating or drinking enough, especially upon arrival to the competition grounds.

Natural supplements containing pre-/probiotics and/or yeast to support gut function can be given daily (Cavalor® Vitaflor365, Cavalor® Digest), prior to transportation or during mild discomfort (e.g. Cavalor® Emergency 911) to prevent or treat minor intestinal disturbances.

Nutritional management after a colic episode

Colic can either be treated medically (first intervention) or surgically (in severe cases).  Since feed cannot properly pass through the digestive tract, most horses will be withheld from feed by putting on a muzzle.  Depending on the severity of the colic this fast can last a couple hours to several days and intravenous fluid should be administered to ensure the horse remains hydrated and receives minimal necessary nutrients.

During recovery of both medical as well as surgical colic a gradual refeeding program is essential to avoid complications.  Since gut function has been shut down or compromised, easily digestible, fibrous feed should be provided, which will typically be in form of warm mashes (e.g. Cavalor® Mash & Mix) in combination with short periods of access to forage.  Keep a close eye on your horse in the first couple days after a colic episode.  When no further problems occur, the horse can gradually be unmuzzled for increasing periods of time until the veterinarian decides the horse is able to have free access to feed.

It is recommended to keep your horse on an easily digestible feed, such as mashes, for about 10 days after which other concentrates can gradually be reintroduced.  These feeds should preferably be high in fiber (e.g. Cavalor® FiberForce) to help regenerate the intestinal environment.

Supplements including pre- and/or probiotics (Cavalor® Vitaflor365, Cavalor® Digest) to further support gut function and strengthen the microbial population in the hindgut are beneficial to rebalance intestinal flora.

When the horse is completely recovered and passes regular, normal manure it can go back to its normal feeding program.  However, recurrence is not uncommon after a colic episode, in particular after surgery, therefore proper nutritional management of these horses is even more important to prevent future problems.

Conclusions

For all horses and in particular those prone to colic it is important to provide a diet that allows for natural feeding behavior.  Pasture turnout is preferred but if this is not possible always supply adequate amounts of hay throughout the day to maintain a healthy microbial environment. Energy dense meals should be fed little and often, avoiding starch fermentation and acidosis in the hindgut.

Prepare your horses properly in anticipation of stressful events and always introduce any dietary changes gradually, allowing the digestive system to adapt.

With proper nutrition and management many colics can be prevented, however in the unfortunate event that your horse does go through a colic episode, act quickly and appropriately.  When colic symptoms are noticed, a natural supplement containing pre- and probiotics such as Cavalor® Emergency 911, can quickly help to rebalance any minor disturbances in the hindgut. However, if no improvement is seen within 30 minutes, call a veterinarian for further medical treatment.
The refeeding program during recovery of a colic should be introduced gradually and consist of easily, digestible feed rich in fiber.

Proper nutritional management is a number 1 priority in the prevention of digestive illnesses!
A healthy gut is a healthy horse!