Feline Leukemia Virus Study Guide

Overview and Clinical Importance

Feline Leukemia Virus (FeLV) is one of the most significant infectious diseases affecting domestic cats worldwide. FeLV is a gammaretrovirus belonging to the family Retroviridae, first discovered in 1964. It affects approximately 2-3% of cats in the United States and Canada, with significantly higher prevalence (up to 30%) in high-risk populations.

FeLV is second only to trauma as the leading cause of death in cats, killing approximately 85% of persistently infected cats within three years of diagnosis. The virus causes a wide spectrum of diseases including lymphoma, anemia, and immunosuppression, making it a high-yield topic for the NAVLE examination.

Virology and Structure

Virus Classification

FeLV is an enveloped, single-stranded RNA virus that replicates using reverse transcriptase to convert its RNA genome into DNA, which then integrates into the host cell genome as a provirus. This characteristic makes the virus capable of lifelong persistence in infected cells.