Hepatic lipidosis is a liver disease primarily affecting cats when they stop eating. Obese cats are particularly at risk. It can ensue within days of complete anorexia. Unfortunately, there is no way to predict which cats and when. Individual cats seem to have an individual predisposition for and rate of developing hepatic lipidosis. Generally, any age or breed of cat can be affected. Hepatic lipidosis is considered a secondary disease, with the primary disease process causing the cat to stop eating. If hepatic lipidosis develops, treatment of the primary condition is complicated and the prognosis usually becomes somewhat poorer.
Hepatic lipidosis is also referred to as fatty liver disease. This is because of the liver literally becomes overwhelmed by an accumulation of excess amounts of fat. When the cat is not eating and no new energy is thus taken in, the body mobilizes energy stores. Fat is one such store. Cats, for some reason, mobilize the fat and deposit it in the liver. The function of the liver then becomes compromised.
Signs of hepatic lipidosis (and altered liver function in general) include: lethargy, nausea, icterus/jaundice (yellowing of the skin, whites of the eyes, and/or gums), vomiting, weight loss and anorexia. The signs are not always clear because the signs of the underlying primary disease process are usually occurring on top of this. Because fatty liver is caused by anorexia and itself causes anorexia, a vicious cycle can develop.
A presumptive diagnosis is based on clinical signs and routine blood work. There are several liver injury and function values on the general chemistry screen that can lead to a suspicion of this disease. Additional function tests can be run individually, if needed. Certain ultrasound findings can further support the diagnosis. Liver aspirates and/or biopsy are needed to definitively diagnose fatty liver, and are valuable for ruling out other liver diseases that may be the primary cause of anorexia.
Treatment is based on getting the cat to eat again. Although this sounds simple, it can be quite difficult and frustrating. Many require a feeding tube, typically into the esophagus, for weeks or even months before they will start eating again for themselves. Appetite stimulants can be used and other supportive and symptomatic treatments are usually indicated. Above all, the underlying disease needs to be identified and treated if possible.
The prognosis for cats with hepatic lipidosis varies based on the severity of the underlying disease, duration of anorexia, liver values etc., but is generally poor to fair. A very dedicated owner is necessary, as rather intense at home care is often needed. The owner must have a realistic understanding of the prognosis, as well. This being said, some cats do very well and go on to have no long-term liver dysfunction.