Although liver problems in horses are relatively uncommon, one every horse owner should be familiar with is hepatic lipidosis. This dangerous condition, in which fat deposits into the liver, is fatal in up to 80% of horses that develop it. And although hepatic lipidosis is most common in Miniature Horses, ponies, and donkeys, the ailment can affect horses of all shapes and sizes.

Philip J. Johnson, BVSc(Hons), MS, Dipl. ACVIM, ECEIM, MRCVS, a professor of equine medicine and surgery at the University of Missouri’s College of Veterinary Medicine, delivered a presentation about the condition at the American Veterinary Medical Association Convention, held July 16-19 in St. Louis, Mo.

Hepatic lipidosis is a condition often prompted by a change in a horse’s eating habits. When a horse stops eating or drastically reduces the amount of feed he consumes (often the result of another factor such as colic or stress) his body does not get the energy it needs to carry out daily functions, as energy comes from converting food into glucose. When this happens, the body tends to find another source of energy. In some cases the body will mobilize fat into the blood stream and send it to the liver to convert it into glucose. As fat builds up in the bloodstream, the liver, and other related organs, the horse’s body stops functioning properly.

When the liver is overcome with fat and isn’t able to clear toxins out of the blood, the horse often feels uncomfortable and will typically reduce feed intake even further. This lack of consumption simply adds to the problem, increasing the amount of fat circulating through the bloodstream and into the liver.