11 Most Common Causes of Colic in Horses [+ How to Prevent]

Symptoms
Treatment
Causes
Types

Colic is a painful, sometimes fatal, condition that strikes fear in the heart of any horse owner. Many cases of colic are mild and can be resolved with veterinary intervention. Others are severe enough to necessitate surgery or euthanasia. ^[1]

Colic is a generalized term is used to describe abdominal pain in horses. It is not one specific condition but rather a symptom associated with numerous abnormalities that affect the horse’s digestive organs.

Horses evolved as hindgut fermenters, grazing for most of the day while constantly moving. However, modern management practices are not always aligned with the natural lifestyle of horses.

Typical practices such as stall confinement and low forage intake have become key contributors to increased risk of colic. ^[1]

The most common types of colic are related to impaction, in which undigested feed or foreign bodies such as parasites block the movement of digesta through the intestines and cecum.

More serious cases involving “twisted gut” or intestinal strangulation can block blood flow to the area, causing tissue death. This must be caught quickly and treated with surgery to avoid further complications, but even surgery does not guarantee survival.

Symptoms of Colic

Symptoms of colic are usually easy to recognize since horses are often visibly uncomfortable.

According to the American College of Veterinary Surgeons (ACVS), common signs of colic include:

Depression
Inappetence (not interested in eating)
Pawing
Looking at the flank
Lying down more than usual or at a different time from normal
Repeatedly lying down and getting up or circling
Curling/lifting the upper lip
Kicking at the abdomen with hind legs
Rolling onto their back
Frequently stretching out like they need to urinate
Dog-sitting
Groaning
Sweating
Increased heart rate
Visible abdominal distention
Less than normal to no manure production
Diarrhea

Foals can experience colic as well. The most common signs in foals are rolling upon their backs, teeth grinding, and salivating excessively.

What To Do If Your Horse Colics

If you suspect your horse is experiencing colic, you should call your veterinarian immediately. With colic, the earlier you can intervene, the better your horse’s chance of recovery will be in most cases.

However, there are several things you can do while waiting for the vet:

Remove access to all hay and feed from your horse.
Walk your horse if he is comfortable enough to do so. (Never force an uncooperative horse to walk.)
Try to keep your horse as calm and comfortable as possible.
If recommended by your veterinarian, administer banamine paste as a pain medication. It is helpful to obtain a temperature and heartrate before giving banamine. If the horse can be kept somewhat comfortable until the veterinarian arrives, intravenous banamine is more efficacious and allows the veterinarian to observe the horse’s condition with no pain medicine.

Once your veterinarian arrives or if you take your horse to the veterinary clinic, several standard colic treatments are usually administered including:

Banamine, Buscopan and possibly some type of sedation to keep your horse calm
Laxatives such as mineral oil or magnesium sulfate administered into the stomach via a nasogastric tube
Rehydration with oral or IV fluids

Depending on what your veterinarian finds upon examining your horse, they may refer you to a surgical canter immediately or they may recommend medical monitoring.

Your veterinarian will perform a physical exam and may also pass a nasogastric tube, used both for therapy and to diagnose some types of colic. They will also likely conduct a rectal examination, and possibly an abdominal tap, an abdominal ultrasound and various blood tests. All of this information helps your veterinarian determine cause, severity, prognosis and treatment plan for your horse.

Top 11 Causes of Colic and How to Prevent Them

Not all cases of colic in horses can be prevented, but there are measures you can take to greatly reduce your horse’s risk of developing this painful condition. Most of these measures revolve around managing and feeding horses as naturally as possible

Here we list some of the top causes of colic, along with what you can do to prevent them.

1) Stall Confinement

Horses stalled more than 50% of the time are at increased risk of colic when compared to horses that have pasture turnout more than 50% of the time. ^[3]

Increased stabling (more than 12 hours per day) has been shown to have noticeable physiological effects on horses. This includes decreased colonic motility, and decreased movement of digesta through the gut. ^[3]

Stall confinement is also associated with wind-sucking or cribbing, which may contribute to an increased risk of colic. ^[1]

The solution to this problem is simple: turnout. By allowing horses as much turnout time as possible, you will automatically reduce their chances of developing colic since both movement and grazing will help keep the digestive system functioning smoothly.

2) High Grain/Low Forage Diets

Horses’ digestive systems are better equipped to process forage than concentrates. Research shows that feeding large amounts of grain or other concentrated feeds can increase a horse’s risk of developing colic.

When a horse is fed a high-grain diet, the digestive tract cannot process and absorb all the sugar in the feed before it reaches the hindgut. This can result in hindgut dysfunction and acidosis.

Twice daily feeding of concentrates is also associated with the secretion of large amounts of fluid into the small intestine which, in turn, leads to the absorption of fluid from the large colon. This can cause dehydration of colonic contents and impaction colic. ^[2]

Feeding horses appropriately can reduce their risk of colic. If concentrates must be fed, feed smaller, more frequent meals throughout the day.

Also, ensure that the majority of your horse’s diet is grass/forage or hay. A horse should consume at least 1-2% of their body weight in forage daily.

You can submit your horse’s diet for complementary evaluation by our equine nutritionists to determine whether your horse is meeting their nutritional and feeding requirements.

3) Inadequate Deworming Practices

In one survey study involving 774 equine veterinarians, researchers found that horses receiving dewormers on a regular basis had a decreased risk of colic.

However, research also shows that administering dewormers to foals can cause colic associated with intestinal obstruction from the rapid death of ascarids (parasitic roundworms). ^[3]

The consensus among veterinarians is that a regular deworming program using fecal analysis to look at parasite load will help to prevent colic in many cases. Check with your veterinarian to see which dewormers are recommended for your area and how often you should administer them.

Having fecal egg counts tested will help you appropriately pick your dewormers, see how well your deworming programs are working and prevent the development of parasite populations that are resistant to our current deworming options.

When deworming your horse, it is a good idea to supplement your horse’s diet with probiotics to restore balance to the digestive tract.

4) Sand Ingestion

Horses grazing or eating off of sandy ground may ingest too much sand which can cause sand accumulation in the colon and colic.

To prevent sand colic, avoid feeding horses on sandy soil. Instead, feed them in raised feeders or hay racks.

Some research suggests adding psyllium, probiotics and prebiotics to the equine diet can help increase fecal sand output to decrease the risk of sand colic. ^[4]

If you live in an area with sandy soil, consider a digestive health supplement containing prebiotics to decrease sand accumulation in the hindgut.

5) Abrupt Feeding Changes

Microbes in the horse’s gut acclimate to digesting certain types of feed and hay. When changes are made too quickly, a disruption occurs in those microbes which can lead to colic.

All feeding changes should be done gradually, over a period of 7-10 days. This goes for concentrates as well as changes in hay or pasture.

If you know that your horse is especially sensitive to any type of feed change, you can even prolong the transition to several weeks.

6) Dehydration

Horses that do not drink enough water are at higher risk of developing impaction colic. Since horses tend to drink less in winter, encourage drinking by providing a warm water source.

In one study, horses in cold temperatures provided with warm water (19^oC or 66^oF) drank 40% more water than horses given water near freezing temperatures. However, horses only consume larger quantities of water when warm water is the sole available option. When both cold and warm water are provided, horses tend to prefer the cold water and drink less water overall.

You can keep your horse’s water warm using heated or insulated buckets, or tank heaters. You can also soak hay cubes or pellets in winter to increase water intake.

Keep in mind that horses cannot lick ice or eat snow to stay hydrated.

It is always recommended to provide free-choice loose salt to encourage drinking throughout the year. A salt lick or salt block will not provide enough sodium to significantly increase water intake. Plain loose salt should always be available to your horse.

7) Moldy Feed or Hay

Mold in feed or hay can disrupt microbes in the horse’s gut and lead to colic. Some types of mold also produce toxins that can cause severe digestive upset. Therefore, never feed grain or any type of concentrate that has been exposed to moisture. If a feed smells off, it’s better to throw it out rather than risk colic.

The same goes for hay: if hay appears or smells moldy, do not feed it. Horses eating from round bales will typically leave any moldy parts alone. However, if their diet is more restrictive, they may eat hay they wouldn’t otherwise consume.

8) Stress

Stress has also been known to cause equine colic. For horses, common stressors include:

Long transport
Stabling changes
Intense training
Increased stall confinement
Changes to the social environment
Herd dynamics

Though not every type of stressor can be avoided, keeping stress to a minimum is an important part of colic prevention, especially for horses with a history of colic.

9) Long-term Use of NSAIDs

Long term use of non-steroidal anti-inflammatories (NSAIDs) is a common cause of recurring and often low-grade colic. Because NSAIDs inhibit chemicals known as prostaglandins, their use can lead to decreased mucous production and a lower gastric pH.

In turn, prolonged use of NSAIDs can cause gastric or hindgut ulcers and recurring colic can be a symptom.

NSAIDs are meant to be used for short term pain management, not as a long-term solution. Phenylbutazone (bute) has the lowest margin of safety as far as side effects are concerned and should not be given to horses with gastro-intestinal disease.

Firoxicib (Prevequine, Previcox) is known to be safer for long term use, but is not as rapid acting and sometimes not as effective a phenylbutazaone.

If your horse is dealing with a chronic issue such as arthritis, talk to your veterinarian about pain management alternatives to NSAIDs. For horses with arthritis or joint pain, we typically recommend MSM powder and w-3 oil with omega-3 fatty acids as natural supplements to support healthy tendons, ligaments and cartilage.

10) Dental Problems

Dental problems can lead to poor chewing and maldigestion, which in turn, can cause both esophageal impaction (choke) and/or intestinal impactions. Horses should receive regular dental care, especially as they age.

For older horses with worn teeth, feeding softer feeds, such as senior feeds, can be helpful. If they have trouble eating hay, consider soaking it or feeding soaked hay cubes or chopped hay.

11) Previous History of Colic

Horses with a previous history of colic or colic surgery are more likely to colic again. ^[1]

If this applies to your horse, it’s important to manage and feed them as naturally as possible.

Consider supplementing with a digestive supplement like Optimum Digestive Health or Optimum Probiotics to help keep the gut’s microbial population in balance and reduce the chance of recurring colic.

Types of Colic

Equine Colic is not one specific condition; it can have multiple causes depending on the type of colic.

The two main classifications for colic are non-strangulating and strangulating, describing whether blood flow to the intestinal tissue is restricted (strangulating) or not (non-strangulating).

Non-Strangulating Colic

Gas Colic

Gas colic occurs when excessive gas or fluid builds up in the horse’s intestines due to over-fermentation of food. Horses with gas colic will often have flatulence and may stretch out like they need to urinate.

The causes of gas colic aren’t always easy to identify, but it has been associated with feed changes, as well as changes in grass, such as new spring growth.

Horses prone to gas colic may benefit from a probiotic or additional support from a complete gut health supplement such as Optimum Digestive Health.

The good news about this form of colic is that, in most cases, it resolves on its own or with minimal veterinary treatment.

Spasmodic Colic

Spasmodic colic is a one of the most common forms of equine colic but is usually temporary and readily treated with Banamine® for pain and Buscopan® to help with gut spasm.

This form of colic involves hypermotility or more frequent contractions of muscles in the gut than normal.

Hypermotility can cause brief bouts of pain, similar to intestinal cramps in humans, and is frequently associated with flatulence in horses.

This type of colic can be associated with tapeworm infection. ^[10] As always, it is recommended to follow a regular deworming schedule to prevent parasite related colic and digestive dysfunction.

Sand Colic

Sand colic can occur when horses living in sandy areas ingest sand when grazing or eating hay or grain off of the ground.

Over time, sand can build up in the large intestine, specifically the right dorsal colon. This can eventually result in a form of impaction (blockage) colic.

Ileal Impaction Colic

This type of colic involves the ileum—the last part of the small intestine. Ileal impaction occurs mostly in adult horses in the southeastern United States and may be associated with feeding coastal Bermuda hay.

Bermudagrass is finer than other types of grasses and may not be thoroughly chewed by horses. These softer fibres are more likely to get caught at the junction of the ileum and cecum, causing a blockage. ^[5]

Coastal Bermuda hay should be introduced into the diet slowly and under guidance by an equine nutritionists to balance the diet, including physical characteristics of the forages.

Ileal impaction may also occur as a result of tapeworms. Therefore, routine deworming targeting tapeworms at least once annually is recommended.

Large Colon Impaction

Impactions can occur in the horse’s large intestine (colon), particularly in sections where the diameter is smaller.

A sudden restriction of exercise due to injury appears to be commonly associated with this type of colic. Also, many large colon impactions are diagnosed in winter, which may be related to reduced water intake, dietary changes, or increased stall confinement. ^[2]

Transitioning to a high-grain diet should be done slowly to minimize changes in intestinal fluid levels that can cause large colon impaction.

High-grain diets require more fluid production in the small intestine which leads to more fluid absorption from the large intestine. This dries out the digesta in the large colon which can lead to compaction. ^[6]

Enteroliths

Enteroliths are mineral stones consisting of magnesium ammonium phosphate that can form inside the large intestine. A horse can develop one or more enteroliths, but if these stones grow large enough to cause a blockage, surgical intervention is needed.

Enteroliths occur more frequently in the western United States, especially California, and have been associated with diets high in alfalfa hay. This is likely because high alfalfa diets result in a higher pH, as well as increased concentrations of calcium, magnesium, and sulfur in the large intestine. ^[7]

Ascarid Impaction

This type of obstruction caused by the parasite Parascaris equorum is almost always seen in weanlings with high parasite loads. If the weanling hasn’t been dewormed regularly, ascarid impaction can occur after they are dewormed and the mass die-off of parasites might obstruct the small intestine.

Foals should be dewormed beginning at 4-6 weeks of age to prevent maturation of the parasites.

Consult with your veterinarian regarding deworming schedule and which anthelmintic to use. Probiotic supplementation might be warranted during deworming to support gastrointestinal health, particularly in adult horses.

Displacement and Entrapment Colic

The horse’s large colon is suspended from the upper body at a single attachment point, allowing it to move around the abdominal cavity.

Displacement colic occurs when a segment of the horse’s gastrointestinal tract, typically the small intestine, shifts or moves from its normal position within the abdominal cavity.

This displacement can result in a partial or complete blockage of the intestine, leading to digestive disturbances and severe pain. The displaced segment of the intestine can become twisted or trapped, further worsening the condition.

Entrapment colic, on the other hand, refers to a situation where a portion of the intestine becomes entrapped or caught between other structures within the abdominal cavity. This can occur when a loop of the intestine gets trapped in a small space or behind a ligament or other anatomical structure.

An example is nephrosplenic entrapment, also known as left dorsal displacement. In this condition, a segment of the large colon becomes trapped over the nephrosplenic ligament, which connects the horse’s left kidney to spleen. ^[12]

A review of gastrointestinal colic cases in western Canada found that large colon displacement was the second most common cause of colic in horses, involving 16.5% of diagnosed cases. Of surgical colic cases, the prevalence of large colon displacement was 24.5%. ^[13]

Strangulating Forms of Colic

Strangulating forms of colic occur when there is restricted blood supply to part of the horse’s intestines, causing necrosis (death) of intestinal tissue. This can lead to severe systemic infections.

These types of colic are often referred to as a “twisted gut” and have a higher mortality rate than forms of non-strangulating colic. They more often present with severe symptoms of pain, including:

Thrashing
Violent rolling
Full body sweating
High heart rate
Poor gum color

Small Intestine Volvulus

In this type of colic, a piece of intestine twists around itself and cuts off blood supply to the small intestine. The middle portion of the small intestine is usually involved.

Prognosis for post-operative survival is considered good, at 80% in one study. ^[8]

Large Colon Volvulus

The large colon can also become twisted, and this is one of the most common types of “twisted gut” in horses. Large colon volvulus occurs most frequently in broodmares either during or right after foaling.

This is one of the most fatal forms of colic However, prompt surgical correction can result in a good outcome. ^[2]

Strangulating Lipoma

Lipomas are fatty lumps that can develop along the mesentery, or folds of membrane attached to the intestines. They can grow with a stalk or stem that may wrap around the intestine and strangulate it.

This form of colic is most common in older geldings and ponies and may be related to fat metabolism, although more research is needed to understand what causes these lipomas to form. ^[2]

Intussusception

One of the rarest and most deadly forms of colic is intussusception, where a portion of the large or small intestine ‘telescopes’ into the adjacent bowel, restricting blood flow to the tissue and causing bowel obstruction. The most commonly affected area is the ileum (the end of the small intestine) telescoping into the cecum.

Horses might be predisposed to this type of colic by tapeworms or other parasites, rapid dietary changes, and enteritis that can alter gut motility. ^[9]

Intussusception requires prompt surgery to avoid irreversible damage. If the horse survives and recovers from surgery, adhesions can be a complication that may lead to death or the need for euthanasia.

Summary

Yes, colic is a worrisome condition and one that horse owners never want to face. But the good news is that it can be prevented in many circumstances if you keep the above considerations in mind.

If your horse has recently experienced colic, consult with our equine nutritionists to identify dietary interventions that can support your horse’s gut health and reduce the risk of recurring colic.