Probably the most common disease condition veterinarians see in horses is colic. Basically, colic is defined as abdominal pain but in most cases, at least in horses, the disease is related to the gastrointestinal tract. However, a recent study indicates that horses with severe colic may also suffer heart damage. The heart rate in many colic cases increases and is a good indicator of the amount of pain the horse is experiencing as well as the severity of the colic. Horses with colic may have: sepsis, which is an infection in the blood stream; hypovolemia, which is decreased fluid volume that leads to decreased circulation: and endotoxemia, which is the release of poisons produced in the body. All of these parameters can affect the heart and cardiovascular status is strongly associated with survival of a colic episode.
Cardiac troponin is a chemical released by the heart in various species when heart damage has occurred. It is a poor prognosis for survival. A recent study was published in the AVMA journal indicating that horses with severe intestinal lesions had increased levels of cardiac troponin in their blood. Because of these levels, it is reasonable that horses with severe colic also have heart damage. Horses in the study that survived had lower cardiac troponin levels than those that did not survive, and it is believed the heart damage is due to decreased perfusion of the heart and small blood clots decreasing blood flow to the heart. It is important to realize that in acute, severe cases of colic, many horses may not survive due to secondary heart disease. The colic itself and the measurement of cardiac troponin may help with the prognosis of colic cases.