Research overview: FeLV-associated lymphoma and leukemia

FeLV is a major cause of hematopoietic neoplasia in cats, classically producing lymphoma and leukemias through insertional mutagenesis and activation of cellular oncogenes. Historically, FeLV-positive cats showed elevated rates of mediastinal and multicentric lymphoma, often at younger ages than FeLV-negative cats. Widespread testing and vaccination shifted lymphoma epidemiology over the decades, with a relative rise in alimentary lymphoma in older, FeLV-negative cats. This overview synthesizes the oncology literature rather than a single study, describing the mechanisms by which a retrovirus drives malignant transformation, how prevention programs changed the disease landscape, and why FeLV remains an instructive model of virus-induced cancer relevant to both veterinary oncology and human tumor virology research.