Colic – The Vets Role
So far this month we have taken a look at Colic – The Different Types of Colic followed by What to do if you Suspect Colic. Carrying on with our focus, here we look at the role the vet takes when visiting a horse with suspected Colic.
The colic examination involves building up a picture of a number of clinical parameters and symptoms, providing vets clues as to what type of colic is occurring. A full clinical examination will be carried out assessing everything from respiratory rate to temperature as well as their general demeanour and condition, however the following observations are particularly useful:-
Mucus membranes (gums) and capillary refill time: By checking the colour, moistness and the speed of blood refilling when the gums are pressed, helps vets to assess the horse’s hydration status and blood perfusion. Normal gums are a pink and moist with a refill time of less than 2 seconds. Concerning signs are alterations in the colour to brick red, paleness, muddy grey or purple and extended refill times.
Heart rate: A normal resting heart rate for a horse is approximately 32-40 beats per minute. Any elevations in heart rate can indicate both pain and/or a compromised cardiovascular system.
Skin tent: By pinching a section of skin, often over the neck, and seeing how quickly it returns to normal can indicate the hydration status of the horse.
Gut sounds: As well as listening to the heart, your vet will also use their stethoscope to determine how active the abdominal contents are. We divide the left and right sides of the abdomen into upper and lower quadrants and group gut sounds into increased, normal, decreased or absent. Increased gut sounds tend to occur with spasmodic colic and reduced gut sounds with an impaction, complete absence of gut sounds is a concerning sign and can indicate a surgical colic.
Rectal examination: Abnormalities within the abdomen (for example an impaction or enlarged loops of bowel due to a twist) if within reach, can be identified by rectal examination. Such examinations do convey a small amount of risk for both horse and the vet. Resentment to the procedure by the horse can result in kicking out and hence injury to the attending vet. The risk to the horse is much smaller but there is potential for a rectal tear. However, the potential benefit of rectal examination is far greater than the small risk to your horse. In order to minimise the danger to both vet and horse we will sometimes use sedation as even the calmest, most gentle horse can become dangerous when it is painful.
Nasogastric tubing: By passing a long plastic tube via the nasal passage into the oesophagus and then into the stomach vets can both diagnose colic and also help correct it. Horses are unable to vomit, therefore if something stops the stomach contents emptying into the intestines (for example due to a blockage) fluid builds up within the limited capacity of the stomach and this is very painful and even runs the risk of rupture. If gastric reflux (stomach contents exciting the stomach via the tube) occurs it is often an indication that the colic could be surgical. Stomach tubing is also used to help administer fluids to a dehydrated horse or to help break down and move impactions.
Abdominocentesis: In certain cases we may perform abdominocentesis or a ‘belly tap’. This is performed by placing a needle into the abdomen to sample the fluid that surrounds the abdominal contents. By analysing the fluid it can give us an indication to the condition of the bowel.
With thanks to Merete Hass BSc (Hons) BVSc MRCVS – Equine Vet at Hampton Veterinary Centre, Malpas, Cheshire