Colic & Constipation

How Impaction Happens

• Feed material that is backed up in a horse's digestion system creates a blockage, or impaction, in the digestive tract. Impaction typically happens gradually, over the course of a few days. The cause of an impaction can be from myriad reasons, including but not limited to too much food, not enough water, limited exercise, heavy parasite load or a problem in the digestive tract itself that has obstructed the passage of digestive matter.

Early Signs

• The horse will show signs of discomfort as soon as his stomach becomes uncomfortable from the build up caused by an impaction. This may take a few days. However, if the horse is kept in close quarters, the owner who is meticulous about cleaning manure out of the horse's living area may notice a reduction or cessation in manure production before the horse shows signs of discomfort.

Other Signs

• The horse who is impacted and whose digestive tract has become stressed with an overload of digestive matter will show the signs of discomfort typical of colic. These signs can be one or all of the following: refusing food, lethargy, biting at the sides, sweating, laying down, rolling, getting up and down frequently or kicking at the abdomen with a hind foot. Heart rate and respiratory rate may increase, depending on the level of pain.

Prevention

• For some horses who have physiological or anatomical problems making them prone to impaction, prevention will be difficult. However, many impactions have an outside cause. Always be sure your horse has unlimited access to fresh water and make note of whether the horse is actually drinking. Horses produce limited saliva given their size. Intestinal motility, or movement of food through the digestive tract, requires large amounts of liquid. Electrolyte imbalances can have a negative effect on intestinal motility. When feeding baled hay, be sure baling twine is not left in the horse's hay pile; twine can become ingested and create an obstruction. Place horse's feed off the ground and keep their feeding area clear of debris so they do not ingest items that can provide the foundation for stone (called enteroliths) creation, which will eventually obstruct the bowel and cause impaction. Hardworking grain-fed horses should be fed their daily ration in several small meals so large amounts do not sit in the stomach increasing the chance of the heavy stomach twisting on itself if the horse were to roll or run shortly after a large meal. Also, deworm horses according to your veterinarian recommendations for your area to prevent impaction from a worm overload or an overload of dead worms causing an impaction at deworming time.

Solution

• If your horse shows signs of colic, always contact your veterinarian immediately. She may suggest you try a dose of flunixin meglumine, a NSAID that will help relieve pain and may relax the muscles enough to resolve the impaction. However, most impaction colics require veterinary attention in the form of "tubing" (a procedure where fluids and mineral oil are deposited directly into the stomach), IV fluids to help rehydrate the animal and perhaps also some pharmaceutical intervention to help increase gut motility. Animals that do not respond to this treatment in a short period of time may require surgical intervention to remove or repair the cause of the blockage. Pre-surgical x-rays and ultrasound will help determine the cause, although in some cases such as enteroliths, the cause may not be evident through these kinds of diagnostics leaving exploratory surgery the only option.