Feline leukemia virus is a leading cause of death in cats. Vaccination, testing, and preventing exposure through responsible management protects cats from this serious and often fatal disease.
Feline leukemia virus causes progressive immune suppression that leads to a cascade of secondary welfare harms. Lymphoma — the most common FeLV-associated cancer — causes tumour-associated pain and organ dysfunction. Secondary infections from immune suppression cause repeated illness requiring frequent veterinary intervention. Anaemia causes weakness and lethargy. Infected cats experience a reduced quality of life that, depending on disease progression, can be managed effectively for a period with supportive care. Prevention is straightforward: vaccination, testing, and management that limits exposure to infected cats. The tragedy of FeLV welfare impacts is that they are largely preventable through these measures. Outdoor cats without vaccination and cats introduced to households without prior testing represent avoidable welfare risks.