Written By: Erin Malone, DVM, University of Minnesota
When your veterinarian arrives to examine a colic, she/he will try to determine the severity and the general type of colic. It is very unusual to be able to diagnose the exact cause of colic, but she/he may be able to determine if it is more likely to be an impaction or gas colic, or if it may involve damaged bowel or toxemia. A routine physical examination will help determine the horse's cardiovascular status and identify signs of shock or toxemia. If the horse is very uncomfortable, the veterinarian may give a short acting analgesic/tranquilizer to aid in performing the examination. Depending upon the situation, the veterinarian may then pass a nasogastric tube (from the nostril to the stomach), perform a rectal examination and/or evaluate the abdominal fluid by doing a "belly tap". The nasogastric tube is passed to make sure there is no fluid build-up in the stomach. If there is fluid, this can be a life-saving measure (to prevent rupture of the stomach). If there is minimal fluid, the tube can be used to give mineral oil to the horse to lubricate any impaction. It may also be used to give water to the horse if it seems to be dehydrated. This has the added benefit of stimulating gut motility. A rectal examination allows the veterinarian to palpate structures in the caudal half of the abdomen. Sometimes an impaction can actually be felt. A rectal examination is always somewhat risky, because of the potential for tearing the rectum. Finally, if your veterinarian is concerned about infection in the abdominal cavity or about damage to the intestines, she/he may stick a needle in the abdomen and try to collect fluid for analysis. This test is most useful for determining if the horse needs surgery and is often not performed unless there is a problem getting the horse to a referral institution or if the colic persists. If you have taken your horse to an equine hospital, other bloodwork and tests (such as ultrasound and radiographs) may also be performed. Continue reading →