The liver is the second largest organ in the body, second only to the skin, which is considered by most to be an organ. Today we are going to discuss liver disorders in horses. The liver plays a role in many different body functions, including metabolism (synthesizing, storing, and excretingvarious compounds), toxin removal, and immunity assistance. Disease of the liver can be the result of a process directly affecting the liver, or it can be injured secondarily by diseases affecting other organs. Typical clinical signs of liver disease include depression, loss of appetite, weight loss, colic, icterus or yellowing of the mucous membranes, and even symptoms affecting the central nervous system can occur.

Diseases of the liver can be acute, such as those caused by bacteria, viruses, parasites, or poisons taken into the body. Chronic liver disease can be caused by long-term exposure to poisons, cancer of the liver, or infections. Liver disease that affects foals from birth are usually related to an abnormality of the large blood vessels that cause blood to bypass the liver when returning from the body and allows it to go directly to the heart. In this condition, the blood is not acted on by the liver and the foal becomes sick due to the toxin buildup. Dr. Neil Williams from the University of Kentucky recently did a review of liver diseases in horses presented to the Kentucky Diagnostic Center and found hepatitis, which is inflammation of the liver, to be the most common liver condition diagnosed in horses. However, there are many other diseases that affect the liver of horses. Join us on our next program when I will discuss specific causes of liver disease.