When digestion goes wrong
Narrow tubes are always prone to getting blocked, and when a blockage of the oesophagus occurs, this is described as choke. It differs to choke in humans, which generally refers to a blockage of the trachea or windpipe. In horses, most episodes of choke will clear on their own, but in some instances, veterinary
intervention may be required.
The most common cause of diarrhoea is a change in diet that affects the water content in faeces, or disrupts/ changes the microbial population within the gastrointestinal system. Other causes may be a parasitic, bacterial or viral infection, a response to drug use, tumours or malfunction of other internal organs.
The risk of ulcers forming is increased by long periods of time spent with an empty stomach. A food ‘mat’ within the stomach helps prevent acid splashing and damaging the upper, unprotected squamous stomach lining. Diagnosis is usually by gastroscopy — feeding a long flexible endoscope (camera) down the horse’s oesophagus and into the stomach so the lining can be examined.
Colic is abdominal pain and may originate from any of the abdominal organs. However, the complex anatomy of the gastrointestinal tract means it’s involved in the vast majority of cases. Colic is broadly categorised into the following:
Idiopathic/spasmodic colic This is the most common type and occurs when the intestine contracts abnormally, creating painful spasms. Idiopathic is a veterinary term for ‘unknown origin’ as, despite investigation, there are still episodes of colic where the cause is never determined. Thankfully, the majority of these respond to simple medical treatment.
Impactions This is when a part of the gastrointestinal system is blocked by food material. It’s fairly common and may resolve with administration of fluids via a stomach tube. Occasionally, larger and more severe impactions will need surgery. Changes in the way a horse is managed is often the cause of impaction colic.
Displacements, strangulations and torsions Displacements happen when one section of the small or large intestine moves to an abnormal location within the abdomen. Strangulating colic describes an episode where the blood supply to a piece of gastrointestinal tract gets cut off. Torsions occur where the bowel twists on itself, cutting off the blood supply. Some displacements can be treated medically but severe ones, and all strangulations and torsions, require surgical correction.