Colic in horses is a generic term that encompasses a combination of signs alerting to abdominal pain. It can vary from mild discomfort that resolves on its own to cases more serious that require emergency surgical intervention. It can affect horses of all ages and types. The incidence of colic is estimated between 4 and 10 percent over the course of the horse’s lifetime and is the leading cause of premature death in domestic horses (Plummer et al, 2007).
The signs of colic in horses vary from case to case, however, horses with colic display some of the following behaviours:
- Rapid respiration
- Get up and down
- Curl their upper lip
- Backing into a corner
- Kick at their abdomen
- Lie down for long periods
- Repeatedly look at their flank
- Paw continuously or intermittently
- Fail to pass droppings for longer than 24 hours.
- Stand in a stretched position as if trying to urinate
There are several different types of colic in horses, all of which occur in the gastrointestinal tract. They can be divided broadly into the following categories:
Table 1: Types of colic in horses (Tinker et al, 1997)
||Occurs when the bowl is contracting in an abnormal manner creating painful spasms and an over-active gastrointestinal tract
||Pain is caused by a blockage in the intestines
||The horse ingests sand (and dirt), which accumulates in the gut. It can lead to inflammation in the bowel, diarrhoea or in severe cases peritonitis. Mostly seen in horses kept on sandy pastures, especially when limited grazing is available.
||There are various sections of the horse’s gastrointestinal tract that may twist upon itself, leading to an interruption in blood supply to that section. A twisted gut is extremely painful and requires emergency surgery.
||Pain is caused by a build-up of gas in horses gut due to excess fermentation within the intestines or a decreased ability to move gas through.
A variety of factors have been identified that may put an individual horse at an increased (or decreased) risk of suffering from colic. Measures to limit exposure to such risk factors can be difficult in some cases, however knowledge of these and proactive observation of signs can ultimately prevent the occurrence.
Exercise: Horses being exercised at least once a week compared to those with no ridden exercise reported an increased risk of colic (Cohen et al, 1999). A sudden increase in exercise can be a risk factor, however, so it is important to gradually increase the exercise program when returning from a break or starting a training program.
Parasites: Parasites are a well-documented cause of colic in horses. Worm larvae release material that irritates the gut, larvae burrow out of the intestine to lay eggs and Strongyles vulgaris, one of the most harmful parasites to the horse, invade the main arterial supply of the gut and can constrict blood vessels by cutting off blood supply. It is important for horse owners to consider ways in which parasitic populations can be reduced.
Feed types and feeding practices: Diets with an imbalance of roughage and concentrate increase the likelihood of colic. Diets should include at least 1% of a horse’s body weight as forage. Ad-lib pasture or hay access maintains the integrity of the gastrointestinal tract. If your horse requires grain due to an increased energy demand such as performance disciplines or racing, it is advised that small concentrates of grain are provided throughout the day with access to hay or pasture in between.
Dietary Changes: Sudden or frequent changes in diet can bring on colic due to the interruption in microbial balance in the intestines. Any changes to equine diets should be gradual and step-wise fashion to avoid a digestive upset and ensure acceptance.
Access to water: Horses with access to clean, palatable water 24/7 have been shown to be at a decreased risk of suffering colic (Cohen, 2003). While this may appear obvious, including electrolytes and salt in your horse’s diet can stimulate the thirst response. Ranvet’s Salkavite and Electrolyte Replacer provide all critical electrolytes needed to replenish those lost through sweat and trigger your horse to drink more water throughout the day. Alternatively, Ranvet’s Salt Lick can be introduced into your horse’s paddock for ad-lib access.
If you are suspect that your horse may be showing signs of colic, contact your veterinarian as soon as possible. Try and keep the horse calm and comfortable and monitor your horse’s vital signs until the veterinarian arrives.
Written by Eliza Barton BAnVetBSc Hons
Sources: Cohen, N.D. (2003) The John Hickman Memorial Lecture: colic by numbers. Equine Veterinary Journal. 35, 343-349.
Plummer, E. E., Bakestraw P.C., Hardy J., Lee R.M. (2007) Outcomes of medical and surgical treatment of caecal impaction in horses. J Am Vet Med Assoc. 231, 137801385.
Tinker, M.K., White N.A., Lessard P., Thatcher, C.D., Plezer K.D., Davis, B., Carmel, D.k. (1997) Prospective study of equine colic risk factors. Equine Veterinary Journal. 29, 454-458.