Feline Hepatic Lipidosis

(Fatty Liver Syndrome)

Hepatic lipidosis, also known as fatty liver syndrome (FLS), is one of the most common liver disorders of the cat.  It is also seen in horses, dairy cows and rarely in very young puppies.  In dogs, however, it is not thought to cause a significant illness.  In humans, it is a serious disease which can occur with pregnancy.

Contributing Factors

In most cases, the cause remains undetermined (Idiopathic FLS).  Obesity and a period of anorexia lasting at least one week are common historical findings.  Less commonly, the fatty liver syndrome occurs secondary to a disease that might lead to anorexia, such as cancer or an infectious disease. 

Prevalence

Idiopathic fatty liver syndrome is most common in cats that are overweight.  Many of these cats have lost up to 25% of their body weight when the liver problems are discovered.  Also, most cats with idiopathic fatty liver are middle aged and female.

Clinical Signs

In the anorexic cat, fat is broken down to supply energy for normal metabolism.  As this fat is mobilized, it is deposited in the liver.  Without an adequate source of dietary protein, the fat cannot be removed from the liver.  It continues to accumulate until liver failure eventually results. 

With time, the cat usually becomes icteric or jaundiced, as evidenced by a yellow color in the whites of the eyes or in the skin.  As toxins normally processed by the liver continue to build up in the blood, the nervous system becomes affected.  Depression, seizures, disorientation, and head pressing will occasionally occur.

Causes/Transmission

As noted above, for most cats, a cause is not determined.  In a few cases, fatty liver develops secondary to a disease that causes anorexia.

Diagnosis

Diagnosis of the FLS is made from blood tests for liver function and from a liver biopsy or fine-needle aspirate.  The latter involves inserting a very tiny needle through the skin and into the liver, removing a small number of liver cells, and examining those cells under the microscope.  The FLS cat will have a large amount of fat in and among the liver cells.

Therapy

This disease is treatable, but aggressive intervention is necessary.  The main thrust of treating FLS is geared toward nutritional support of the cat until it begins to eat voluntarily.  A consistently high quality diet will allow the liver to resume functioning so it may remove the fat.  This does not occur quickly; it takes an average of 6-7 weeks.  Therefore, a method of tube feeding must be used to allow you to feed your cat at home.