Resting is normal, but if you see a horse repeatedly lie down and get up, or if he’s assumed an odd position, he may be colicking. Photo by Bob Langrish.

The word colic strikes fear in every horse owner’s heart. While we have come a long way in understanding, treating and reducing the risk of colic in horses, colic is  still something that can take your horse’s life. Colic remains on the top of the list of medical emergencies.

What Is Colic?
Colic is abdominal pain in horses that can have many causes. Basically, a problem with any of the organs in the abdomen can cause abdominal pain—liver, spleen, urinary tract, reproductive tract or intestines. The vast majority of horse colics are caused by problems in the intestinal tract, but because the symptoms are largely nonspecific, only a veterinary exam can tell you what’s causing the problem.

Symptoms of Colic
The horse will "tell" you his belly is hurting in a variety of ways. Some of these are fairly specific for abdominal problems; others are not.

• Kicking at the belly. Unless the horse is being bothered by flies, this is a fairly specific symptom.
• Turning to look at and/or biting at the belly or flank. Same as kicking at the belly. The horse may rest quietly, or may alternate between lying flat and lying on his sternum.
• Restlessness. Horse may lie down and get up repeatedly, or pace.
• Nosing at water but not drinking.
• Grunting or groaning. Usually more likely to do this when they are down. May also be present with chest pain. Some horses may lift their lip or grind their teeth.
• Pawing at the ground. May indicate more severe pain than the previous signs.
• Rolling and/or thrashing when down. This indicates severe pain. Foals will often lie on their backs with their feet in the air.
• Change in manure. This includes no/less manure, diarrhea, change in size of the fecal balls, manure covered with mucus (which will look like a veil).
• Excessive gas production, abnormal abdominal sounds, or a complete lack of sound. Gut sounds that are obviously louder than normal and can be heard without a stethoscope. (Your vet will also use a stethoscope to detect other abnormalities in the intestinal sounds, including hearing no sounds at all.)
• Abnormal postures. Standing stretched out or a horse sitting on his haunches like a dog.
• Changes in mouth and gum color. Abnormally pale, or abnormally red or dark, or failure to regain color when pressed upon.
• Nonspecific signs that tell you the horse is distressed. These include depression, poor appetite, sweating, increased pulse rate, breathing more rapidly.

Types of Colic
Any condition involving an abdominal organ will cause the symptoms of colic. It doesn’t have to involve the bowel. Heavily pregnant mares for example are often colicky because the ligaments of the uterus are being stretched or due to slight twists in the uterus. If your horse is showing colic symptoms though, odds are he probably has an intestinal problem.

The simplest type of colic is spasmodic or "gas" colic. When this happens, a segment of intestine isn’t moving normally. Gas starts to build up and the horse gets uncomfortable. The exact sequence of events is usually not clear. There are several potential causes of irritation to the bowel, including parasites, digestive upset from a new feed, toxins in a feed, temporary displacement of a section of the bowel, partial obstructions (incomplete impaction), even irritation from sand/dirt in the gut.

Enteritis is inflammation of the bowel, usually caused by some type of infectious organism. If you have ever had food poisoning or a viral infection in your bowel, you know how painful this can be.

Handling a Horse in the Throes of Pain Colic is a painful and frightening condition for your horse. When in the throes of pain, even the most mild-mannered companion can become a raging monster. To help understand the situation, think of your colicking horse like a woman in labor, who may react in a seemingly irrational manner. Now, image your horse, who doesn’t understand why he’s in pain, and you can understand how behavior can change during an episode of colic. Just as women rely on practiced breathing techniques to relax and work their way through birthing, your horse’s basic training can help focus him while he’s colicking. You’ll probably want to keep your colicking horse on his feet and moving. To make this happen, he’ll need a confirmed go-forward cue. But keep in mind that even a well-trained horse might be reluctant to move forward when he’s in pain. On the other hand, a distressed horse could try to bowl you over if he’s not already conditioned to respond to your cues. College-level leading should be an important part of your regular training. That way, if the time comes, you can ask your horse to move away from you, even if he is upset. Your horse will also need to stand for examination, so work on your horse’s relationship with the veterinarian during routine calls. The horse that shies from the vet during vaccinations will be even more difficult to handle when under stress from colic. A horse prone to kicking or biting is likely to fall back on these defenses when he’s under stress, making him a danger to you, your veterinarian and himself. To help reassure your horse, try to keep a calm exterior. You’re right to feel scared or helpless, but try to keep your own negative emotions in check, and instead focus your energy on your horse’s needs. Finally, try not to take personally how your horse acts during a period of colic. He doesn’t know why he hurts, and he probably doesn’t understand that you’re just trying to help.

Although not terribly common, abscesses can form in the wall of bowel as a result of a partial puncture, or anywhere in the abdominal cavity after an infection in which bacteria were present in the blood (such as strangles or pigeon fever). These abscesses may be present for a very long time before they begin to cause problems because they have reached a large size. Abscesses as large as basketballs have been found.

Impaction is a common cause of colic. Blockages may occur due to large numbers of parasites (roundworms in foals, tapeworms in adults), or because a section of bowel has been damaged and is sluggish. But probably the most frequent cause is inadequate fluid in the bowel, which slows the movement of feed through the GI tract, causing the contents to start backing up. Impactions in the small colon may also occur after bouts of diarrhea, presumably because of irritation and abnormal movement of the bowel. Impactions can also be caused by enteroliths, which are stones that can form in the intestinal tract, or by build-ups of sand.

Most serious are problems that involve the loss of blood supply to a section of bowel. This can occur if the bowel becomes twisted, if a segment of bowel telescopes inside another segment (called intussusception), or if the bowel moves from its normal position and becomes trapped. In a displacement, that section of bowel may fill with gas and the pressure eventually shuts off the blood supply. The latter could happen with hernias for example. Lipomas are fatty tumors on stalks that can form in the abdomen and may become wrapped around the bowel like a bolero, shutting it off.

When to Call the Vet

This one is easy. Always call the vet if you think your horse has colic. Depending on the information you give your vet about the history and symptoms, he can decide if the horse needs to be seen right away. Either way, your vet will be alerted to the problem and can give you suggestions on things to try to help your horse until he arrives. With mild spasmodic colics, walking, or even longeing, the horse is often one of the first things to try. Light exercise may be all it takes to get the gut moving well again. However, this is a judgment call for your vet to make. Never give any pain-relieving drugs without the vet’s knowledge and instructions to do so. These can mask symptoms enough that your vet will not get a true impression of what’s going on with the horse.

What to Expect

When your vet arrives, he’ll first do a general physical exam, including careful monitoring of the chest and abdomen with the stethoscope. After this, if the horse is very agitated or distressed, he will likely give your horse pain-relieving drugs.

Your vet will pass a stomach tube to see if there is any fluid build-up on the stomach and upper intestinal tract. This can happen when there is a blockage or twisted/displaced section of bowel. It’s important to relieve that pressure on the stomach so it doesn’t rupture. Your vet will also do a rectal exam to feel for distended bowel, displaced bowel, or impactions. Your vet may also put a needle into the lower abdomen to attempt to retrieve some of the fluid surrounding the bowel. This will be collected into a tube for laboratory analysis, but the amount of fluid obtained and how it looks can also give your vet valuable information about what might be going on inside the abdomen.

Depending on your vet’s findings, and the information you are able to give, you and your vet will decide whether to treat the horse there or refer him to a surgical hospital. A referral doesn’t automatically mean your horse will have surgery, but it gives you more options in case the situation worsens. Some cases need more sophisticated diagnostic procedures to determine the best plan of action, and other cases require more intensive medical therapy than might be available at your own place.

Treating Colic

Spasmodic colic is treated by medications that relieve the spasms and by walking. The horse will sometimes need more than one dose of medication, but this type of colic generally responds to treatment.

Impactions rarely require surgery, but clearing them may take anywhere from a day to even a week. Pain medications like Banamine will help relieve the horse’s discomfort, and may be needed more than once a day. To clear the impaction, your vet will administer mineral oil or stool softeners, fluids, and electrolytes via stomach tube. Fluids may also be given intravenously to help rehydrate the horse. Some vets use enemas as well to help break up the blockages. However, some impactions may be too extensive to break up without surgery, so you and your vet will want to closely monitor the horse’s progress. Grass is the ideal food for a horse with an impaction, and regular walking or turnout will be encouraged. Otherwise, vets vary in their feeding recommendations. Soupy meals of soaked hay pellets or beet pulp are usually recommended rather than dry hay.

Enteritis does not require surgical treatment, but often the horse is in so much pain, with dehydration and changes in the gums, that a decision is made to do surgery just in case there is something going on that requires it. Once it is clear what the problem is, the treatment becomes intensive fluid therapy and antibiotics plus anti-inflammatories.

Surgical Solutions

A horse with a displaced or twisted section of bowel whose blood supply is compromised will need surgery to correct the problem. Horses with large enteroliths or abdominal abscesses also need surgery,

If it becomes clear your horse does need surgery, you’ll want to know what his chances of survival are. Some formulas have been developed that are fairly accurate (75% to 90%-plus) at predicting survival rates. Theses point systems rely on blood and abdominal fluid tests performed in a lab, and some of these tests are only available at full-service hospitals or clinics. So the bottom line is, your vet just won’t be able to answer that question for you at your barn. Once you get to the hospital and the tests are in, you’ll have some idea of the odds for your horse.

Reducing the Risk of Colic

Because of the complicated nature of the horse’s digestive tract, and the fact that much of the bowel is essentially floating loose inside the abdomen rather than securely held in position, some colics are basically accidents that you cannot prevent. That said, several studies have identified clear risk factors.

Inadequate water intake. The horse’s intestinal tract can hold as much as 35 gallons. Until you get to the very end of the gut, a large percentage of that is water. Much of the fluid in the gut comes either from saliva (a horse produces about 10 gallons per day), or fluids secreted along the intestinal tract, but the water in those secretions has to come from the horse’s diet or water bucket.

The horse’s natural diet, grass, is at least 80% water. When the horse eats grains or hays that are less than 10% water, he has to make up the difference by drinking. For optimal digestive tract health, a horse on a "dry" diet needs to take in at least 8 gallons per day of water. In summer heat and when exercising, needs are considerably higher. Insufficient salt is a common reason why horses don’t drink enough water. Make sure your horse has access to salt and also make sure he’s actually taking it in. He needs at least 1 ounce/day in winter, 2 to 4 ounces/day in hot weather.

Feed changes. While we’ve been repeatedly told to make any switches in grain slowly, fewer may realize that changes in hay can have an even greater impact on our horses’ health. Hays can and do vary tremendously in the levels of sugar, starch, protein and fiber types they contain. All these different nutrients are fermented by different types of organisms in the horse’s intestines. When you make a sudden change, they may not be able to adapt. Even if you always feed the same type of hay (such as orchard grass), there can be sizeable differences between cuttings and hays grown in different locations. Always try to make changes gradually, over about a week’s time.

Too much grain. Grains are low-fiber, high-starch feeds that are more suitable for humans than horses. The horse has a limited ability to digest starch due to a relatively short small intestine where that digestion occurs. Sugars and starches that don’t get digested end up in the large bowel and can cause serious problems. Equally bad is that horses eating grain do not take in as much fiber from hays. Most horses are fed way too much grain. You should only feed grain if your horse can’t hold a normal weight on hay alone. Limit grain feedings to 3-5 pounds, at the very most, per feeding. Remember, too, that brans and pelleted supplements often contain considerable amounts of sugar or starch, anywhere from two to three times as much as hay.

Inadequate deworming. The problem of parasites as a cause of colic, especially chronic, recurrent colics, has dropped considerably since the modern paste dewormers came on the market, but parasites still can be a problem. This is particularly true of roundworms in foals and tapeworms or small strongyles in adults. Young horses require more frequent dewormings than adults. Small strongyles are now resistant to many of the paste dewormers, so if you are using a rotational deworming plan, you need to talk to your vet about periodic fecal exams to make sure the products you’re using are getting the job done. Tapeworms aren’t sensitive to most of the common dewormers, so you need to attack these twice a year with either an ivermectin or moxidectin combo product labeled for tapeworms, or a month of a daily dewormer containing pyrantel tartrate.

Inadequate exercise. Exercise encourages good intestinal motility. A horse confined to a stall is a colic waiting to happen.

Through proper management practices, you can reduce your horse’s chances of colic and ward off tummy troubles that otherwise could threaten your horse’s life.