Colic in Horses: Why It Is a Symptom, Not a Disease

By Dr Duncan Houston

Colic is one of the words horse owners dread most. That fear is understandable, because colic can be mild and short-lived, but it can also become life-threatening quickly.

The most important thing to understand is this: colic is not one disease. It is a sign that your horse has abdominal pain. That pain may come from gas, an impaction, sand, a gut displacement, inflammation, parasites, toxins, reproductive pain, urinary problems, or another internal issue entirely.

That distinction matters. If you think of colic as one disease, it is tempting to look for one prevention method or one treatment. In reality, the safest approach is to recognize the signs early, call your vet promptly, and reduce known risk factors through consistent management.

Quick Answer

Colic in horses means abdominal pain. It is a symptom, not a diagnosis. Some cases are mild and respond to veterinary treatment within a few hours, but others involve obstruction, gut displacement, strangulation, shock, or conditions that require hospital care or surgery. Any horse showing signs of colic should be taken seriously and assessed by a veterinarian, especially if signs are severe, worsening, or not resolving. Colic is widely described by equine veterinary sources as a broad term for abdominal pain rather than a single condition.

What Does Colic Actually Mean?

Colic simply means your horse is showing signs of abdominal discomfort.

Most colic is related to the gastrointestinal tract, but the term itself does not tell us the exact cause. A horse may show very similar signs whether the problem is gas, an impaction, sand accumulation, a twisted section of bowel, enteritis, ulcers, or pain coming from outside the gut.

This is why colic should never be treated as a “wait and see for days” problem. The early signs may look vague, but the underlying cause can change the urgency dramatically.

Common signs include:

MSD Veterinary Manual notes that common signs include pawing, looking at the flank, kicking at the abdomen, lying down, rolling, sweating, stretching as if to urinate, reduced appetite, depression, and fewer bowel movements. It also points out that these signs indicate abdominal pain, but they do not identify which part of the digestive tract is affected. (MSD Veterinary Manual)

Why Calling Colic a Symptom Changes Everything

When owners ask, “How do I prevent colic?” the honest answer is: you cannot prevent every case.

That does not mean prevention is pointless. It means prevention should focus on reducing risk rather than chasing miracle cures.

Colic can happen because of management changes, hydration issues, feeding patterns, parasite burden, sand ingestion, stress, dental disease, toxins, motility changes, or problems that are not fully predictable. The American Association of Equine Practitioners states that not every case is avoidable, but management plays an important role in reducing risk. Its recommendations include routine feeding and exercise schedules, forage-based diets, avoiding excessive grain, regular parasite control, turnout, fresh water, and avoiding feeding on sandy ground.

In practice, the goal is not to make colic impossible. The goal is to make it less likely, recognize it earlier, and respond fast enough that a manageable case does not become a disaster.

What Usually Causes Colic in Horses?

Colic has many possible causes. Some are mild. Some are surgical emergencies.

Common causes

Gas or spasmodic colic
This can happen when gas builds up or the bowel spasms. These horses may look painful but can sometimes improve with veterinary treatment.

Impaction colic
This occurs when feed material, dehydrated ingesta, sand, or other material blocks normal passage through the intestine. Reduced water intake, dry forage, poor dentition, and sudden management changes can increase concern.

Sand colic
Horses fed on sandy or dusty ground may ingest sand with hay or grain. Over time, sand can accumulate in the large intestine and cause irritation, blockage, or more severe bowel problems. University of Arizona Cooperative Extension explains that horses can ingest sand from soil along with hay, grain, or pasture forage, and that sand may build up in the digestive tract and eventually cause colic. (UA Cooperative Extension)

Feed-related digestive upset
Sudden changes in hay, grain, pasture, or feeding schedule can disturb the hindgut environment. A systematic review in PLOS One found that management change is one of the most commonly identified risk factors, with feeding management changes and housing changes repeatedly associated with increased colic risk. (PLOS)

Large colon displacement or torsion
The large colon can move into an abnormal position or twist. These cases are often more serious and may require referral or surgery.

Parasites
Parasite burdens can contribute to digestive irritation, obstruction, and colic risk, especially when parasite control is inconsistent or not guided by veterinary advice.

Enteritis or colitis
Inflammation of the intestine can cause pain, fever, diarrhea, dehydration, and systemic illness.

Non-gut causes
Pain from the urinary tract, liver, spleen, uterus, pregnancy complications, or other abdominal organs can mimic gastrointestinal colic.

The key point is that the signs alone rarely reveal the exact cause. That is why veterinary examination matters.

How Worried Should You Be?

Colic should always be taken seriously, but not every case carries the same risk.

Low concern, but still call your vet

Your horse is mildly uncomfortable, still bright, has normal gum color, is not repeatedly rolling, and symptoms are brief or improving.

This may be a milder gas or spasmodic episode, but it still needs veterinary advice because early colic can change.

Action: Call your vet, describe the signs, remove feed, keep water available unless your vet advises otherwise, and monitor closely.

Moderate concern

Your horse is off feed, pawing, looking at the flank, lying down more than usual, has reduced manure output, or seems uncomfortable for more than a short period.

This is the point where waiting becomes risky. A moderate colic can still be medically manageable, but the window for early treatment matters.

Action: Call your vet promptly. Do not give medication unless your vet directs you, because pain relief can mask worsening signs.

High concern

Your horse is repeatedly rolling, sweating, getting up and down, showing increasing pain, has no manure output, has a distended abdomen, has abnormal gum color, or seems dull and weak.

These signs raise concern for obstruction, severe impaction, displacement, strangulation, shock, or systemic illness.

Action: Treat this as urgent. Call your vet immediately and be ready for referral if recommended.

Critical concern

Your horse is violently painful, cannot be safely handled, collapses, has very pale, dark red, purple, or muddy gums, has a very high heart rate, is severely bloated, or pain returns quickly after treatment.

Action: This is an emergency. Do not try to manage this at home. Call your vet or an equine emergency service immediately.

When Is Colic an Emergency?

Colic is an emergency when pain is severe, persistent, worsening, or associated with signs of shock.

Call a vet immediately if your horse:

• Repeatedly rolls or thrashes

• Sweats heavily without exercise

• Refuses all feed and looks distressed

• Has no manure output or very dry manure

• Has a swollen or tight abdomen

• Has pale, purple, dark red, or muddy gums

• Has cold ears or limbs

• Seems weak, depressed, or disoriented

• Shows fast breathing or a very elevated heart rate

• Has pain that returns after initial improvement

• Has signs lasting more than a short period without clear improvement

The real concern is not just the discomfort itself. The concern is what may be causing it. Some causes of colic can become life-threatening in a relatively short time, which is why AAEP emphasizes rapid recognition and veterinary help.

What Should You Do Right Now If Your Horse Has Colic Signs?

1. Call your vet early

Do not wait until the horse is dramatically painful. Mild signs are easier and safer to assess early than severe signs later.

Tell your vet:

• When signs started

• Whether your horse has eaten or drunk

• Whether manure has passed

• Whether there has been a recent feed, hay, pasture, turnout, travel, or housing change

• Whether your horse is rolling, sweating, or repeatedly lying down

• Gum color, if you can safely check it

• Heart rate, if you know how to measure it safely

2. Remove feed, but keep water available unless advised otherwise

Feed can worsen some impactions or add bulk to a gut that is not moving normally. University of Minnesota Extension notes that vets often recommend withholding hay and grain until manure passes and the colic resolves, because feed may add to an impaction. (University of Minnesota Extension)

3. Keep the horse safe

A horse that wants to roll can injure itself or you. If walking is safe, gentle walking may help some horses and reduce rolling. If the horse is too painful or unsafe to handle, leave it in a safe area and wait for veterinary help.

Do not exhaust the horse by walking for hours. That old advice has caused plenty of tired horses and tired humans.

4. Do not give medication unless your vet advises it

Pain relief can be appropriate, but it can also hide important clinical signs. Your vet may want to assess the horse before medication or may guide you on what to give based on the situation.

5. Monitor changes every 10 to 15 minutes

Watch for pain level, rolling, sweating, manure, appetite, water interest, gum color, and general attitude.

If signs worsen over minutes to hours, escalate immediately.

How Do Vets Diagnose Colic?

A vet is not just trying to confirm that the horse has colic. They are trying to work out how serious it is and whether the horse can be treated on the farm or needs referral.

A colic exam may include:

• Heart rate and respiratory rate

• Gum color and capillary refill time

• Gut sound assessment

• Rectal temperature

• Abdominal palpation, where appropriate

• Nasogastric tubing to check for reflux and give fluids or medication

• Rectal examination, where safe and indicated

• Blood tests

• Ultrasound

• Abdominal fluid analysis

• Referral for hospital monitoring or surgery

University of Minnesota Extension describes several diagnostic steps that may be used, including nasogastric tubing, rectal examination, blood work, ultrasound, radiographs, and abdominal fluid testing in selected cases. It also notes that some colics resolve with treatment within a few hours, while more severe or unresolved cases may need hospital care or surgery. (University of Minnesota Extension)

Why “Colic Prevention” Is Never One Simple Fix

There is no single supplement, feed additive, or routine that prevents every type of colic.

A horse can colic because of dehydration, sand, sudden feed change, parasites, stress, poor dentition, gut displacement, inflammation, toxins, or events no owner could reasonably predict. That is why good prevention is boring in the best possible way: routine, forage, water, movement, gradual changes, parasite control, dental care, and close observation.

Boring management saves dramatic vet bills. Not always, but often enough to matter.

Practical Ways To Reduce Colic Risk

1. Keep clean water available at all times

Water is one of the most important colic prevention tools, especially for reducing impaction risk.

Check water daily. In winter, make sure it is not frozen. In hot weather, during travel, or after exercise, expect water needs to increase.

Some horses drink better from buckets than certain automatic waterers. Oklahoma State University Extension notes that horses given a choice have shown strong preference for buckets over automatic waterers, and that low-flow or noisy waterers may reduce intake in some horses. It also notes that horses prefer lukewarm water over icy water in cold conditions, and limited winter drinking can contribute to dehydration and colic risk. (extension.okstate.edu)

2. Base the diet on forage

Horses are designed to eat fibre steadily through the day. High-quality hay, pasture, or appropriate forage should form the foundation of the diet.

AAEP recommends a diet made primarily of roughage and avoiding excessive grain or energy-dense supplements. It also advises dividing concentrate meals into smaller feedings rather than giving one large meal.

3. Avoid sudden feed, hay, or pasture changes

Changes in hay are often underestimated. Owners may carefully transition grain but switch hay overnight. The hindgut still notices.

Make changes gradually over 7 to 14 days where possible. This includes:

• New hay batch

• New concentrate

• Increased pasture access

• Change from dry lot to grazing

• Change in meal size or timing

• New supplements that alter intake or palatability

A systematic review found that feeding management changes, including changes in hay, concentrate, and diet, were associated with increased colic risk across multiple studies. (PLOS)

4. Provide turnout and regular movement

Movement supports gut motility. Horses kept stalled for long periods may have reduced natural movement, increased boredom, and greater disruption to normal feeding patterns.

Daily turnout, walking, grazing, or controlled exercise can all help, depending on the horse’s age, health, workload, and environment. AAEP includes daily exercise and turnout among its colic risk reduction recommendations.

5. Reduce sand ingestion

This matters most in sandy, dry, dusty, or overgrazed environments.

Useful steps include:

• Feed hay in nets, tubs, mats, or feeders

• Avoid feeding directly on sandy ground

• Use rubber mats beneath feeding areas

• Keep feed areas swept and clean

• Avoid letting hungry horses scavenge on bare sandy soil

• Ask your vet whether sand testing or imaging is appropriate if your horse is at risk

University of Arizona Cooperative Extension recommends not feeding horses on the ground and using tubs, hay nets, or feeders to reduce sand intake. It also notes that mats under feeders can help catch dropped feed and further reduce sand ingestion. (UA Cooperative Extension)

6. Maintain a consistent routine

Horses cope best with predictable feeding, turnout, exercise, and management.

Risk often rises around changes:

• Moving yards

• Travel

• Competition

• Sudden box rest

• New turnout group

• New feed supplier

• Weather disruption

• Change in handler or routine

The more changes happen at once, the harder it becomes to know what triggered a problem.

7. Use targeted parasite control

Parasite control should be planned with your vet, not guessed. Fecal egg counts, pasture management, and appropriate deworming all matter.

Over-worming without strategy is not good medicine. Under-worming high-risk horses is not good medicine either. The right answer is targeted control.

8. Keep dental care up to date

Poor chewing can increase the amount of long, poorly processed fibre entering the gut. That can raise concern for choke, weight loss, and some impaction risks.

Dental checks are especially important for older horses, horses dropping feed, horses quidding hay, and horses losing condition.

Common Mistakes Owners Make With Colic

Waiting too long to call the vet

This is the big one. Calling early does not mean you are panicking. It means you are protecting the horse.

Assuming rolling always means “just gas”

Some gas colics roll. Some surgical colics roll. The behaviour does not tell you the full diagnosis.

Giving medication before getting advice

Pain relief can be useful, but it can also blur the picture. Always speak to your vet first.

Feeding to “settle the stomach”

Food is not a safe home treatment for colic. In some cases, it can make things worse.

Walking the horse endlessly

Gentle walking can help if safe. Exhausting a painful horse is not helpful.

Ignoring recent management changes

A new hay batch, new pasture, travel, reduced turnout, missed water, or change in routine may be clinically important. Tell your vet.

Will a Horse With Colic Be Okay?

Many horses recover well, especially when colic is recognized early and treated promptly. Mild gas or spasmodic colic may resolve with veterinary care. Some impactions improve with fluids, pain relief, and careful management.

The outlook becomes more guarded when pain is severe, persistent, recurrent, associated with shock, or caused by bowel displacement, strangulation, severe inflammation, or obstruction. University of Minnesota Extension notes that many cases respond to treatment within a few hours, but severe cases, intensive cases, or cases that do not resolve on farm may need hospital care. (University of Minnesota Extension)

The practical takeaway is simple: early assessment improves decision-making. It also gives your horse the best chance if the cause turns out to be serious.

FAQs About Colic in Horses

Is colic in horses always serious?

Colic should always be taken seriously, but it is not always life-threatening. Some cases are mild and respond quickly to treatment. The problem is that early signs do not reliably tell you whether the cause is mild or severe.

Can colic go away on its own?

Some mild colic signs may settle, but you should still call your vet for advice. A horse that improves briefly and then becomes painful again is more concerning.

Should I walk a horse with colic?

Only if it is safe. Gentle walking may reduce rolling and support gut movement in some cases, but it is not a cure. If the horse is violently painful, unsafe, weak, or exhausted, do not force walking.

Should I let my horse eat during colic?

Usually no. Remove hay and grain while waiting for veterinary advice. Keep water available unless your vet tells you otherwise.

Can supplements prevent colic?

No supplement prevents all colic. Some products may have a role in specific situations, but the foundations are water, forage, gradual feed changes, turnout, parasite control, dental care, and consistent management.

Final Thoughts

Colic is not a single disease. It is your horse showing abdominal pain, and that pain deserves attention.

The safest mindset is to treat colic as a warning sign, not a diagnosis. Some cases are mild. Some are not. What matters most is recognizing the signs early, calling your vet promptly, and managing the risk factors you can control.

Good colic prevention is not glamorous. It is clean water, steady forage, daily movement, gradual changes, thoughtful parasite control, dental care, and a routine your horse can rely on. That quiet consistency is often the best protection you can give.

If you are unsure whether your horse’s signs are urgent, or you want help thinking through ongoing risk factors, ASK A VET™ can support you with clear, practical guidance.