Feline Hepatic Lipidosis Study Guide

Overview and Clinical Importance

Feline hepatic lipidosis (FHL), also known as fatty liver syndrome, is the most common acquired hepatobiliary disease in cats, accounting for approximately 50% of all feline liver disease diagnoses. This potentially fatal intrahepatic cholestatic syndrome is characterized by excessive accumulation of triglycerides within hepatocytes (greater than 80% of hepatocytes affected), leading to hepatocyte dysfunction, intrahepatic cholestasis, and liver failure.

The condition develops when cats experience a period of anorexia (as short as 2-7 days), triggering peripheral fat mobilization that overwhelms the liver's capacity to process and export lipids. Understanding FHL is essential for the NAVLE as it represents a true veterinary emergency requiring aggressive nutritional intervention.

Etiology and Classification

Primary (Idiopathic) Hepatic Lipidosis

Primary or idiopathic FHL occurs in approximately 5-10% of cases when no underlying disease can be identified after thorough investigation. These cases typically occur in obese cats following stressful events such as diet changes, new household members, moving to a new home, boarding, or accidental confinement. Environmental stressors lead to anorexia, which triggers the metabolic cascade resulting in hepatic lipid accumulation.