Colic Pathology: Compact Guide

There is a long, exhaustive list of the causes of Colic and includes anything from heart problems to infection. It is, therefore, simpler to break the causes into two main groups; digestive tract related and non-digestive tract related.

Non-intestinal tract related illness can include, but not limited to; foaling, placenta retention, abortion, uterine torsion, pleuritis, botulism, renal and bladder stones, ruptured bladder, hepatitis, myositis and laminitis.

However Colic is much more commonly due to Digestive Tract conditions and diseases. The horse's intestinal tract is highly complex and has evolved over 1,000’s years to adapt to a diet of continuous grazing and the breaking down of the complex cellulose molecule found in grass. However, this finely tuned system is susceptible to disruption and consequently can result in these common conditions;

1) Distension: the digestive tract cannot perform the worm like movement to move food along.
2) Simple obstruction or blockage: Food cannot move along the tract due to a blockage.
3) Obstruction or blockage and partial or complete blood supply cut off: This can cause severe pain and can quickly develop into septicaemia.
4) Inflammation: Swelling can cause distension and stasis of the digestive tract.
5) Colon Displacement: more commonly found in Warmbloods. If the displacement of the colon is to the left, it will become lodged between the Spleen and left Kidney. If it is to the right, it will invade the area of the Cecum (a large digestion vat).

Delving a little deeper we can take a look at the more common root causes of these conditions;
1) Gas accumulation: this is the most common and can be due to a decrease in the horse's movement (i.e. if they are standing still for long periods of time) and accumulation of feed.
2) Impactions: feed impactions can be the result of poor dental health or dehydration, this can then lead to gas accumulation. Sand impactions, as suggested is the result of ingesting sand from feeding off the ground. Sand ingestion will be more problematic depending on the geographical location, for example, it is a common problem in California.
3) Enteroliths are mineral accumulations and can form a rock like substance in the large colon, remain there and accumulate over time and consequently can eventually become obstructive. Genetics plays a part, but this is more likely to be related to diet;
Arabian’s are predisposed to the condition.
4) Lipomas Are fatty tumours and are usually a disease of old age. In the later stages of the disease, they can block the tract and cut off the blood supply.
5) Infection: Examples include Salmonella, Clostridium and Potomac Horse Fever and will result in inflammation. Parasite infection can also result in impactions.

So there we have it. An extremely simplified, guide to how and why Colic may occur. With so many root causes it’s easy to understand why Colic is such a common occurrence in our four legged friends. Knowing the pathology also allows us to calculate how Colic can be avoided. Thus, following on from this, our next instalment of our Colic series will be top 10 Techniques to Prevent Colic.

Colic: is severe abdominal pain and the symptom of digestive tract, liver or kidney disease. 

All equestrians are well aware of the major health concern Colic poses to our close companions. Colic is the number one cause of a premature death and while most can be treated the best approach to dealing with Colic is prevention. There are many variations of the condition caused by a range of factors due to the complex nature of the equine digestive tract, but these 10 techniques will greatly help reduce the risk of Colic occurring in your beloved horse.

  • Routine: Maintain a regular schedule of feeds and exercise. Exercise/turnout should aim to be achieved daily.

  • Diet: should consist primarily of high-quality mould free hay and avoid 100% alfalfa hay. Split grain and supplement feed into smaller portions more often rather than one large portion less often.

  • Parasite control: Have regular check ups.

  • Water: simple but effective. Ensure fresh, clean and cool water is always readily available.

  • Medication: Anti-inflammatory and pain relief drugs can cause stomach ulcers just as they do in humans. Limit their use and always to be taken with food.

  • Sand: Avoid consumption of sand from feeding off the ground, use buckets or mats where possible.

  • Stress: Always observe your horse closely and their food consumption after particularly stressful incidents such as changes in their environment or heavy workload.

  • Toxins: Weeds, pests and indigestible matter such as bailing twine, inspect your horse's environment regularly and remove these objects.

  • Foaling: Pay close attention to mares while foaling as they are at risk.

  • Observation: Last but not least, pay close attention to the behaviour of your horse and watch for signs of Colic. Like most diseases, catching it early will significantly increase the effectiveness of treatment.

Erin McCaffrey