When you go to the barn for evening chores you hear banging in the far stall – your horse is down and rolling. He gets to his feet when you run to the stall, but immediately starts pawing and circling and quickly drops down again to roll. He’s sweaty and in pain – clearly, he’s colicking. But this is not the first time this has happened. After your vet comes and treats him again for “just a gas colic,” you ask yourself, “what can I do to avoid calling the vet once a month for my horse’s colic?”

Preventing colic in horses starts with understanding what causes equine colic, then making adjustments to your horse’s dietary routine, introducing probiotics and prebiotics, avoiding equine obesity and parasites, and keeping up with regular dental care.

What causes equine colic?

Horses are more prone to digestive upset than other domestic animals because of how their gastrointestinal (GI) tracts function and how we feed them. The horse evolved as a grazing animal, and its digestive tract is designed to utilize forage. It functions best and remains healthiest when they’re allowed to roam at pasture, eating continuously and consuming small amounts often. In domesticating horses, we’ve confined them and typically feed hay and grain in scheduled meals. This unnatural environment often leads to digestive problems and colic.

Horses are one of a few animals that digest most of their feed in the hindgut (cecum, colon, and large intestine) rather than in the stomach and small intestine. The horse’s GI tract is designed to transfer food to the hindgut as swiftly as possible. Feed can travel through the small intestine to the hindgut in a matter of a couple hours, which can create digestive problems if owners offer high volumes of grain per feeding, because some reaches the hindgut before it is fully digested.

Horse feed schedule: Small amounts of forage, often

You can improve your horse’s digestive health by managing his dietary regimen the way nature intended. Ideally, a horse’s diet should be comprised of good-quality forage (hay or pasture), with added grain and concentrates only if their level of work demands it.

The trouble with a large concentrate meal is there’s not enough time to digest it in the small intestine. It moves down to the hindgut too quickly, and the microbe population shifts toward those that can rapidly digest starch, creating gas in the process. If the horse is not able to adequately pass the gas, it can stretch the wall of the intestine, leading to painful signs that owners recognize as colic. If the change is too severe, with large proliferation and die-off of certain bacteria, toxins might be produced, leading to more serious problems such as laminitis.

Keeping your horse moving while they graze helps keep circulation going, simulating pre-domestication free ranging, when they were walking all the time. Ensuring your horse eats small amounts continually keeps their digestive tract moving, promoting gut motility. While proper gut motility can be challenging to achieve for horses that live in stalls, the risk for colic increases the more a horse stands still, especially if they are standing still without anything to eat.

While turnout that allows a horse to graze continuously is best, this might not be realistic for your situation. If a horse must be confined, maximize the amount of forage you feed. Alterations like feeding forage in a slow feeder so your horses stretch those two flakes out to four instead of 30 minutes has been shown to minimize colic or abdominal pain. Daily turnout, longeing, or any other type of daily exercise can also be beneficial to digestive health.

Prebiotics and probiotics for horses with colic

For the horse’s fermentation-focused digestive system to process forage, the hindgut’s microbial population must be healthy, with appropriate numbers of helpful bacteria. Many horse owners feed commercial supplements or feeds containing some of these microbes. Use of these products (called probiotics) began several decades ago in an attempt to replace normal gut flora after animals were sick (and not eating) or given oral antibiotics that destroyed good bacteria along with the bad. Now we have multiple probiotic and prebiotic products that can stabilize the good microbes. They also have some effect in guarding against harmful bacteria, helping maintain normal gut function.

Recent studies on various strains of pathogenic bacteria showed that only probiotics normally found in the equine digestive tract were effective in decreasing their growth. Probiotics that work for a dairy goat or a cow may not be as effective for a horse.

In contrast to probiotics, prebiotics are a newer development and not microbes; instead, they’re ingredients that feed and maintain the microbes. Prebiotics are indigestible sugars that make their way through the digestive tract, stimulating beneficial bacteria growth. Some of them trick bad bacteria into binding to them and are excreted in manure. These can benefit a horse that has a sensitive gastrointestinal system or a hard time with diet and stress.

Ask your veterinarian about prebiotics and probiotics for horses with colic; your horse may benefit from adding probiotics and/or prebiotics to their diet.

Prevent equine obesity

Obesity and parasites also are risk factors for colic, but a conscientious owner can prevent and manage these concerns. A horse should be fed by weight, not volume, because the density of hay varies from bale to bale. Horses should be pastured on non-irrigated, dryland pasture when possible. If the only pasture option is a rich, irrigated field, then many problems, including obesity, can be avoided by fitting a horse with a grazing muzzle or by limiting turnout time. This prevents intake of highly fermentable, rich grass that can contribute to gas or spasmodic colic episodes.

Avoid parasites with regular equine deworming

Small strongyles and tapeworms are the most worrisome of the internal parasites that can lead to colic, and they are ironically not found on most routine fecal tests that you may request. Tapeworms cause as many as 22% of spasmodic colic cases across the U.S., with more cases found in the northwest and southeast states. Parasite control is managed with regular deworming schedules using an appropriate anthelmintic. Dewormers with praziquantel are the only products that effectively kill tapeworms. The only dewormer that can kill both tapeworms and small strongyles with one administration is Quest® Plus Gel.

Cleaning up manure at least twice a week limits development of other infective parasite larvae in areas where the horse might eat. Pasture rotation limits overgrazing and facilitates ultraviolet kill of remaining infective larvae.

Routine equine dental exams

Poor mastication (chewing) can lead to maldigestion, and esophageal and intestinal impactions. To help prevent colic, we recommend your horse receive routine oral examinations. Have your veterinarian check your horse’s teeth on an annual basis until age 18-20, then have bi-annual dental checks and dental floats performed. Routine dental care may be a long-term investment, but two equine dental exams a year for your geriatric friend is still cheaper than an emergency colic visit on Thanksgiving night.

Tips for preventing colic in horses

  • Feed at least 60% of the daily ration as forage (hay or pasture). Current recommendation is 1-2% of body weight per day in forage.
  • When possible, pasture in non-irrigated fields, and/or use a grazing muzzle to control weight and intake of rich forage.
  • Limit grain to as little as possible – high fat/low starch is preferable.
  • Provide feeding systems that limit the intake of sand and dirt.
  • Provide plenty of turnout and exercise each day.
  • Provide clean, ice-free drinking water. Add powdered electrolytes when travelling or at horse shows to minimize the risk of dehydration.
  • Implement regular and frequent deworming programs for the herd. Consult your veterinarian to see what they recommend for your horses.
  • Implement a herd health program of preventive care dentistry on an annual basis.
  • Minimize stress (transport, herd dynamics, housing, illness, injury) as much as possible.

Unfortunately, the cause of any colic episode often goes undiagnosed, and many times, colic may be initiated by a combination of factors. Although some factors are believed to play an associative role in increasing colic incidence, the reality is most colic episodes occur due to undefined causes and all or none of the above risk factors for colic may contribute to any one episode. Consult with your veterinarian to work through the possible causes of your horse’s colic, and develop a plan to keep your horse healthy.