Horse Colic

If you are reading this because your horse has colic now, we suggest you go straight to section Emergency Suggestions, at the bottom of the page.

Colic means 'abdominal pain'; it is not an illness in itself but rather a symptom. There are many different causes of colic (pain in the abdominal region), some of which are minor issues which normally go away by themselves (e.g. the pain which a mare may experience after giving birth) and others of which require emergency treatment (e.g. a twist in the intestine). Although many cases of equine colic fall into the former group, serious cases of colic occur often enough that it is a leading cause of death in horses (most studies indicate at least 10% of domestic horses die from colic) and some horse mortality studies have concluded that it is the main cause of pre-mature death in domestic horses. 

The main topics covered below are:

  • 1.0 Colic Causes
  • 2.0 Colic Prevention
  • 3.0 Colic Symptoms
  • 4.0 Colic Remedies & Treatment
  • 5.0 Why do Horses get Colic?
  • 6.0 Emergency Suggestions

For information on other equine illnesses, click on horse disease.

1.0 Colic Causes

The most serious forms of colic are due to problems with the digestive system. For example, the intestine twisting (preventing passage of feces and cutting off blood flow), blockage of the intestine (preventing passage of feces and gas), movement of the stomach out of its correct position. For a detailed discussion of these types of colic, click on this horse colic article, which is a good article for intestinal colic but does not cover the other types in detail. 

Some common causes of colic are:

  • Blockage of intestine. The intestine can be blocked, preventing the passage of feces and gas (leading to painful bloating). Possible reasons for blocking include
    • Dental issues. If the horse is unable to chew its food properly, the inadequately chewed food can form a blockage. This can happen due to dental issues (e.g. teeth worn down or painful) or pain in the jaw joints (making chewing painful). Both conditions are common in older horses due to wear.
    • Incorrect food. If a horse eats inappropriate food (such as stall bedding), it may not be adequately brooken down, leading to blockages. Eating of stall bedding (straw, or other types) occurs in many horses, although fortunately in the majority of cases it does not lead to blockage.
    • Foreign materials. Many horses ingest foreign materials, which cause blockages. For example, horses that are bedded on sand may ingest some of it (especially if they are fed in their stables and food falls on the sand bedding). Likewise, horses that are on overgrazed pastures may ingest sand and dirt, leading to impaction (or internal abrassion, leading to infection).
    • Bolting. Horses that 'bolt' their food (swallow quickly, with inadequate chewing) can have food blockages due to the food being inadequate chewed or inadequated moistened or a combination of the two.
    • Water. Insufficient access or consumption of water can result in food drying out in the intestine and forming a blockage.
  • Displacement of colon. Variety of causes, including excessive rolling or horse becoming 'trapped' (e.g lying against a wall or fence and unable to get up).
  • Intestinal worms. Excessive intestinal worms can cause blockages (or even deadly punctures) of the intestine. For details on worm types, symptoms and treatment, click on Guide to Horse Worming.
  • Ulcers. Stomach and intestinal ulcers are relatively common in horses, especially horses which are fed infrequently or fed concentrated food or have limited access to pasture. It is also associated with stress (e.g. frequent transport and showing) and use of certain medications (non-steroidal anti-inflammatory drugs).
  • Infections. Various types of infections (e.g. of urogenital or respiratory tract) can result in abdominal pain.

2.0 Colic Prevention

The best treatment for colic is prevention; ensuring that the horse does not get colic in the first place. To avoid the common causes of colic:

  • Worming. Ensure that the horse is on a regular deworming schedule. All other horses which share the same pasture should be on a syncronized deworming schedule, to prevent cross-reinfection. If a horse has a heavy infestation of worms to start with (e.g. if it has not been dewormed for a long time), then the actual deworming itself can be dangerous, so one should use a laxative to reduce the worm population prior to starting a deworming schedule. 
  • Food and Pasture. Horses have evolved to eat and digest throughout the day. Their digestive systems are based on 'continuous processing', rather than periodic feedings (such as one finds in people or large carnivores). Consequently, restricting them to feedings only twice or even a few times per day is unnatural and places a strain on their system. The ideal situation is for the horse to spend the majority of its time on pasture, constantly eating and moving. If this is not possible, it should be fed as often as possible so that one comes as close as possible to the 'continous processing' it has evolved for. One should never feed food which has gone off (e.g. moldy, fermented).
  • Hay before Grain. The horse digestive system is designed for 'high volume, low calorie' food such as grass and hay; foods which are 'low volume, high calorie' such as grain does not provide the volume they require and can lead to various medical conditions (in particular, ulcers). Consequently, use high-roughage foods in preference to grains, unless there are specific reasons otherwise (e.g. for intensive sports, grain may be neccessary).
    • Furthermore, if one is providing both hay and grain, the hay should be fed first. One reason for this is that by reducing appetitie with hay, it is less likely that the horse will 'bolt' the grain (see 'bolting' below). Another reason is that there is evidence that hay following by grain is digested much better than grain followed by hay.
  • Soak Pelleted Food. It is adviseable to soak pelleted food before feeding to horses. The main reason for this is that pelleted food expands in contact with water, so if a horse 'bolts' a large quantity of dry pelleted food, it can rapidly expand to an excessive volume upon contact with fluids in the stomach. By pre-soaking the pellets, the food is expanded before it is eaten. This also reduces the rate at which the horse eats, reduces the risk of choke and ensures that additional water is ingested (for horses that are poor drinkers).
  • Excessive Feed. Horses sometimes manage to get into the feed stores (e.g. where you store grain or other high-calorie food) and stuff themselves, which can result in colic. It is wise to keep the room with feed locked, so that if a horse gets out of its stable or pasture, it will not be able to get into the feed room.
  • Bolting. If your horse 'bolts' (swallows without chewing) its food, discuss options with your veterinarian. For example, with hay pellets one can pre-soak them in water.
  • Water. Ensure that the horse has access to water at all times. If for some reason the horse has not had water for some time, provide water in small amounts at first rather than allowing it to drink a large amount at one go (particularly after exercise). Likewise, if a horse has not been drinking for some time (horses often refuse to drink during transport), ensure that when it resumes drinking that it is gradual.
    • During winter, try to provide warm drinking water. A study by the University of Pennsylvania School of Veterinary Medicine determined that this increased water consumption by 40% (warm water compared to near freezing water). As inadequate water comsumption is an important cause of colic (impactioni colic), providing warm water is advisable. Further, there is strong ancedotal evidence that consumption of large quantities of cold water in a short time (e.g. after exercise or after water deprivation) can cause colic.
  • Exercise. Colic can be caused by inadequate exercise (e.g. horse spends most of day in stall), excessive exercise (especially if horse is out of condition), or rapid changes in the amount of exercise. Consequently, one should avoid these extremes.
  • Bedding. Ensure that the horse does not eat its bedding, certainly not in large quantities. If it persists in eating its bedding, change to another bedding type which it does not eat.
  • Sand and Dirt. Do not feed the horse on sand or dirt surfaces. Avoid stabling the horse on sand or dirt. Do not leave a horse on over-grazed pasture.
  • Dental Care. Correct and periodic dental care (e.g. annual examination, with work if required) will minimise the risk of horses not chewing their food properly due to dental pain.
  • Trapped. A horse will sometimes lay down or roll so that its back is against a fence or wall, with the result that it cannot get up. Remaining in this position for a lengthy period risks serious colic (e.g. movement of colon into a dangerous position), so if one sees a 'trapped' horse one should quickly move it, taking care to avoid accidental injury to oneself. Likewise, a horse that lays down in a paddock sometimes gets its legs trapped under or in the fence rails and needs to be freed.
  • Temperature. Extreme temperatures (very high or very low) and rapid temperature changes can cause stress on a horse, particularly those which are weak (old or sick). During extreme weather, consider keeping the horses in their stalls. Alternatively, there are a range of horse jackets to protect from rain and/or cold. These should be used if there are sudden extreme changes in weather or if a horse is weak. In addition, although stables should have good ventilation, they should not be drafty (in general, drafts are more of a risk than simple cold).
  • Change. Finally, one should be aware that horses do not react well to change or stress. One should minimise these as much as possible; if a period of change or stress is neccessary (e.g. long distance transport, changes to feed), one needs to monitor the horse much more closely than normal and take special care of it. The ways in which change can affect a horse negatively are numerous. For example, horses will often stop drinking during periods of stress or if they are moved to another area where the water tastes different. As another example, adding or removing a horse from a herd can upset the herd social dynamics, resulting in considerable stress.

One of the more interesting studies into the causes of colic is 'Dietary and Other Management Factors Associated with Equine Colic' by Noah Cohen, VMD, PhD; Pete Gibbs, PhD; and April Woods, BS. Using the histories of horse colic cases, they calculated for each of the following factors the increase in risk. For the following table, a value of 1.0 is no increase in risk, a value of less then 1.0 is decreased risk, a value of 2.0 is double the normal risk.

Factor Risk Multiplier
Recent diet change 5.0
Recent change of hay 9.8
History of previous colic 3.9
History of previous abdominal surgery for colic 4.6
Weather change during 3-day period before examination 3.2
Recent change in stabling 2.3
Regular deworming program 0.4 (60% reduction in risk)
Not on regular deworming 2.2
Anthelmintic received during 7-day period before examination 2.1
Arabian breed 2.1
Age > 10 years 1.5

 

3.0 Colic Symptoms

The obvious sign of colic is the horse being in pain. There are a number of symptoms (e.g. those based on rectal examination, or extraction and examination of stomach fluids) which are normally considered only by veterinarians. Among the symptoms which are easily measured by the non-medical horse owner are:

  • Decreased abdominal digestive noise. An increase in digestive noises, although less common, can also indicate colic. 
  • Increased heart rate and/or increased respiration rate
  • Addominal distension, contraction, or muscle spasms
  • Fecal examination for changes in quantity, consistency, or foreign materials (e.g. sand)
  • Behavorial changes (e.g. Pawing and/or scraping, Stretching , Frequent attempts to urinate , Flank watching: turning of the head to watch the stomach and/or hind quarters, Biting/nipping the stomach, Pacing, Repeated lying down and rising , Rolling , Groaning, Excess salivation , Loss of appetite, Refusal to eat). A horse that throws itself on the ground and rolls violently may well be in the final stages of colic; it is dangerous to be around until sedated (even the most gentle horse can be dangerous when in this much pain) and will likely need immediate emergency treatment (quite possibly surgery once it has reached this stage).

4.0 Colic Remedies & Treatment

There are two forms of treatment for colic: treatment when the cause of the colic is unknown and treatment once the cause has been identified. 

When the cause of the colic is unknown, many vets will:

  • Get the horse on its feet and keep it on its feet, preventing it from lying down or rolling. The reason for this is that rolling (especially the violent rolling of a horse in pain) can move the stomach out of its correct position (or, if it is already out of its correct position, make the situation worse). Consequently, keeping the horse on its feet can prevent further damage.
  • Walk the horse, to encourage the digestive system and blood circulation, as well as preventing the horse from lying down.
  • Give an injection direct into a vein (normally in the neck) to provide pain relief and as an anti-inflamatory. This is partly done to reduce the suffering of the horse but mainly because many types of colic can be successfully treated during the early stages in this way. A horse in colic often has tight abdominal muscles which are in spasm; by reducing pain and inflamation the muscles can relax and this can allow the digestive system (if displaced) to work its way back into the correct position rather than being pulled further out of postion by muscle spasms.

These actions are often taken before the examination is complete or the cause of the colic definitely determined. One reason for this is that the earlier colic is treated, the better the response, so many veterniarians prefer to do a quick initial treatment, followed by a more lengthy examination and diagnosis. The second reason is that the reaction of the horse to this treatment provides some diagnostic information as to the severity and type of colic.

Once the exact cause of the colic has been determined, more specific treatments can be applied. As there are douzens of different types of colic, it is not surprising that there is a great range of different associated treatments. Here are some examples of real cases, to illustrate the diversity of colic and treatment.

  • Post-birth colic, exacerbated by stress. A 4-year old mare (Rusty) had given birth to her first foal. After birth, the owners noticed that the mare was in discomfort and that the abdominal muscles were in spasm. The veterinarian's diagnosis: initial pain due to giving birth, becoming worse due to stress of nearby horses (the mother felt threatened by the presence of other horses near her newborn foal). The treatment was simply to remove the other horses from the vicinity, allowing mother and foal to relax. Muscle spams and colic soon went away naturally.
  • Digestive issues due to cold. An elderly horse (Misou) appeared to be in discomfort and lathargic. The veternarian observed that the digestive system made much less sound then normal (a horse's stomach makes constant noises, associated with digestion), the body temperature was below normal, and that recent weather had been colder than normal. The diagnosis was that the cold weather had led to a drop in body temperature, causing slowdown and consequent problems with digestion. Immediate treatment was to move horse to warm stable for a gradual increase in body termperature, with advice that horse should wear a horse jacket during particularly cold weather (a rain-proof jacket, if it rained during cold weather). Colic gradually improved during the day, although it was 24 hours before the horse was fully normal and active.
  • Displaced colon, unknown cause. Aprroximately 2 weeks after moving to a new stable, a 6-year old mare (Maybeatle) was found in the morning lying down in the stable in distress. A veterinarian was called out and determined that the digestive system was abnormally quiet and gave standard treatment for colic (pain relief, anti-inflamatory, walking). Over the next 2 hours the mare became more distressed and repeatedly tried to lay down and roll. Veterinarian called out second time and advises that horse goes to specialist clinic. The clinic uses ultrasound examination to determine that the colon had moved and immediately begins intensive treatment (including repeated treatments of paraffin into the stomach via tube). Estimated 50/50 chance that the treatment would be successful; if not the horse would require emergency surgery to save. After 24-hour treatment and observation for a further 2 days, the horse was able to return to its owners (cost for treatment - approximately 2000 euros). Following a short period of rest, it returned to full and active health.
  • Twisted intestine. During morning stable mucking out, stallion found to have colic. A veterinarian administered normal treatment. No improvement by early afternoon so further treatement administered. By mid-afternoon the owners were advised to transport the horse to a clinic for treatment. Horse loaded into trailer but died during transport to the clinic.

When faced with a case of colic, both owner and veterinarians face the dilema of how aggressive to be in treatment. In many cases, minor treatment is sufficient so there is a reluctance to incure the financial and time costs of taking the horse to a specialist clinic (equipped with ultrasound and other diagnostic equipment) for examination and possible treatment. However, in some cases (e.g. twisted intestine), the routine colic treatment is unlikely to have any positive effect and the horse requires surgery within hours if it is to be saved. The great problem is that the average general veterinarian who is examining the horse on-site (rather than in his clinic) often lacks both the diagnostic equipment and the experience to always detemine the severity of colic (minor or emergency), with the result that the horse may not be sent for specialist treatment until it is too late. The second problem is that even if surgery may save the horse's life, the cost of such surgery is often greater than the financial value of the horse; an important consideration for uninsured horse owners. In our experience, the number of horses which die from colic is largely due to these two factors.

As a final note, a study by the Morris Animal Foundation concluded that anti-inflamatory drugs which are often used as a colic treatment (to reduce inflamation and pain) slow down healing after colic, so such drugs should be used in moderation.

5.0 Why do Horses get Colic?

The horse digesttive system has a number of traits which makes it predisposed to problems. These include:

  • A horse has a long intestine, which can become entangled (twisting, knoting) more easily due to its length.
  • The digestive process in horses produces a large volume of gas through fermentation. This large volume can exacerbate any problems (e.g. partial blockage, or temporary displacement of colon or intestine).
  • Unlike humans, a horse cannot vomit if it eats something unsuitable. Consequently, unsuitable materials (e.g. moldy hay) are forced through the digestive system.
  • Horses have evolved to be foragers (note: foragers, not grazers), moving and eating most of the day. When their movement is restricted and/or the eating period is shortened, as often happens with domestic horses, their digestive systems have difficulty coping.

 6.0 Emergency Suggestions

 If your horse has colic now and you don't know what to do, here are our suggestions:

  1. Call a vet immediately. Only a trained person can tell you if the colic is serious or not. If it is serious, you can't waste hours on the internet educating yourself on colic, your horse will need immediate treatment.
  2. If your horse is in a lot of pain, is rolling around on the ground, or behaving very strangely. Any one of these is an indication that the colic may well be very serious. In this case, you should insist on a veterinarian urgently (e.g. less than an hour). If your vet is unavailable for some hours, contact another veterinarian. If you end up speaking with a receptionist on the phone (rather than a veterinarian) who does not understand the situation, make it clear that you have a potential emergency colic. If you cannot get a veterinarian promptly, consider loading your horse into a horse trailer and taking it to a specialist clinic.
  3. Call a friend. Don't waste a lot of time phoning about (your horse needs you) but if you can quickly get a friend over (perferably one that knows horses), it may well come in handy.
  4. Do not let your horse roll. If your horse is rolling, it is very important that you stop it, as rolling can make the colic much worse. Get it on its feet (even if you have to use force) and walk it (it is more difficult for it to get down and roll while it is walking).
  5. Walk the horse. Encourage the horse to walk. This helps prevent rolling and also helps gets the digestive system moving properly. Of course, you don't want to exhaust the horse or stress it out by using a lot of force to get it to walk. However, if you can gently pursuade it to a slow and steady walk, this is a good thing.
  6. Make the horse comfortable. Try to make the horse comfortable. For example, if it is over-heated, move it into the shade. If it is cold, put a warming blanket on it.
  7. Stay with the horse. Stay with the horse and follow steps 4 to 6 until the veterinarian arrives. If there is a sudden change and you feel that you need to call the veterinarian clinic or load it into a horse trailer, this is where a friend's help is useful as one person can be with the horse while the other can be making any required arrangements.
  8. Specialist Clinic. A specialist horse clinic has more equipment and expertise than a general veterinarian to deal with horse colic. If the horse is getting worse rather than better after the first visit by the local veterinarian, rather than waiting for a 2nd and then 3rd visit, you need to consider if it is time to go to a specialist clinic. Although clinics are generally expensive, prompt treatment by a specialist may be cheaper, since waiting until the colic gets much worse may result in much more intensive treatment being required (or may even mean the loss of your horse).

These suggestions are not a substitute for professional veterinarian advice. We take no responsibility (legal, moral, or otherwise) for their completeness or accuracy. They are a personal opinion, based on our experience.