Colic in horses 

The word ‘colic’ means ‘abdominal pain’. So colic is not a single disease – rather it is a clinical sign of a range of different conditions. Depending on the cause, the pain can range from mild to severe, and from transient to continuous. The vast majority of colic cases involve a problem with the gastrointestinal tract (i.e., the stomach, small intestine, or large intestine).   

The main types of gastrointestinal colic are:  

• Gas (tympanic) colic: accumulation of gas in the intestines  
• Spasmodic colic: periodic spasms of the intestines  
• Impaction colic: presence of a mass, usually made of food or partially formed faeces, in the intestines  
• Sand colic: accumulation of sand in the intestines  
• Enteritis/enterocolitis: inflammation of the intestines  
• Displacement colic: movement of a part of the intestine to an abnormal position  
• Strangulating colic: any type of colic in which a part of the intestine loses its blood supply (this is the most dangerous form of colic for the horse) 

Sometimes, the underlying cause of a case of colic is obvious – for example it could be due to a tumour, worms, or equine grass sickness. Often, however, the reason for development of excessive gas, unusual spasms, an impaction, or a displacement is never known.  

The clinical signs of colic pain range from mild to severe. The most obvious signs include restlessness, pawing, rolling, and flank-watching (looking round at the flanks). Less easy to spot are the early and more subtle signs which may include lying down more, eating less, and/or passing fewer droppings than normal. This is why knowing what is normal for your own horse is so important – if you don’t know what is normal, you won’t be able to spot when things are abnormal. Other cases that may be missed are the horses that started experiencing colic during the night or during a period when they were not observed and that are found muddier than normal (if they are turned out) or with cuts or abrasions to their head or bony prominences. These injuries are common in horses that have rolled violently and should alert you to the fact that something is wrong.   

Colic-like signs are sometimes shown by horses with conditions unrelated to the gastrointestinal system. These include laminitis and urogenital discomfort. However, it is usually fairly straightforward for a vet to determine that a horse has abdominal pain (i.e., colic). What is not always so easy is determining which type of colic the horse has. However, in most cases, this is not that important – the important thing is for the vet to determine, as soon as possible, whether or not the horse requires referral to an equine hospital (if this is an option), and to provide immediate pain relief and appropriate treatment. If the horse requires surgery, the chances of success depend heavily on them arriving at the referral clinic as soon as possible. However, this is only one of many reasons that you should make an emergency call to your vet at the first signs of colic. Other reasons to do this include: 

• A vet can provide pain relief which will help to alleviate the horse’s suffering (note that you should never do this yourself, unless you have been advised to do so by a vet) 
• Although the severity of colic signs usually mirrors the severity of the disease, this is not always the case – any case of colic is potentially extremely serious and early diagnosis and appropriate management can, quite literally, make the difference between life and death 
• The signs shown by the horse may be due to something other than colic; a vet will be able to determine this and provide immediate, appropriate treatment – something that is important for conditions such as laminitis

When you call your vet, they should give you advice on how to manage the situation until they arrive. Typically, they will advise allowing continued access to water but not feed. Depending on the horse’s condition, they may also advise limited hand walking. However, this should only be done on the recommendation of your vet and never to the point that the horse is tired. The most important thing is to keep yourself and all other personnel safe (horses with severe colic and in significant pain may be very dangerous to handle) and to keep the horse as safe as their condition and the facilities allow. This is often most easily achieved by putting the horse in a well-bedded box from which you have removed anything on which the horse could hurt themselves. Horses that are found in the field with colic are also often best brought into a stable, particularly if it is dark, as colic cases require constant monitoring and this is much easier to do in the light. 

You should not give the horse any medication, as this can make it more difficult for the vet to decide whether referral to an equine hospital is necessary. When the vet has assessed the horse, they will advise on treatment and management options.  

Some cases of colic are so severe that the horse requires transport to an equine hospital for life-saving medical treatment or surgery. However, this may not be an option, perhaps because the horse is now too sick to be transported or because the estimated cost of such treatment is prohibitive or greater than your vets’ fees insurance limit. In this situation, the priority must be to keep the horse as comfortable as possible during a period of continued monitoring. If the horse’s condition deteriorates further, if their pain cannot be controlled, or if it is obvious that surgery is required but is not an option, euthanasia should be performed to prevent further suffering. 

Risk factors and prevention

The cause of an episode of colic may never be known. However, we know a lot about factors that affect the risk of colic. To minimise the risk you should:  

• Ensure that the horse’s diet is composed mostly of forage (grass, hay, or haylage)  
• Make any changes in diet gradually, preferably over 10–14 days  
• Minimise the amount of concentrates fed, feed only low starch/sugar feeds, and split any concentrates fed into as many feeds/day as possible  
• Ensure that the horse always has access to fresh, clean water  
• Never allow horses to graze on sparse grazing on sandy soils  
• Never feed grass clippings or unsoaked sugar beet 
• Follow a vet-led worm control programme  
• Have your horse’s teeth checked by a vet or equine dental technician (EDT) every 6–12 months  
• Minimise the number of hours spent stabled and maximise grazing time  
• Allow as much turnout/free exercise as possible  
• Make all changes to routine (e.g., 24/7 stabling vs turnout, amount of exercise) gradually  
• Minimise the number of people who care for your horse, and ensure that all carers know your horse’s habits and routine  
• Be particularly careful in checking for signs of colic after travelling (transport increases the risk), especially if water has been withheld