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.
Some people believe that it is important to take a horses temperature if they think the horse is colicking. The general thought is that if the horse has a temperature, then they shouldn't' be walked, if he doesn't, then its ok to walk him. However, this is not really the case. Some types of colic are associated with fevers and it is okay to walk the horse to keep him comfortable while waiting for the veterinarian to arrive. However, diseases such as pleuritis, tying up, and laminitis may show signs similar to colic and walking is contraindicated. Pleuritis is inflammation of the chest cavity (pleurisy). It can be detected by pain when the ribs are pressed. Tying up is due to muscle trauma. Muscles (especially in the hindquarters) may look swollen and feel firm. Laminitis or founder leads to heat in the foot and the horse is often reluctant to pick up either foot since it hurts to stand on the opposite limb. In general, if the horse feels better walking, do it. If walking seems to make the horse worse or if you detect signs of rib pain, foot pain, or muscle pain, then stop.