How FeLV affects cat welfare and what supportive care can achieve for affected cats.
FeLV-positive cats can live good-quality lives with appropriate management, though their prognosis is variable and depends on whether they have progressive or regressive infection. Cats with progressive FeLV infection require close monitoring and prompt treatment of secondary infections to maintain welfare. Quality of life remains high during asymptomatic periods, and many owners successfully maintain FeLV-positive cats in enriched indoor environments for years. The welfare harm comes from the uncertainty of the prognosis, the need for monitoring, and the eventual progression in cats with progressive disease. Vaccination prevents this welfare burden for susceptible cats, making FeLV vaccination one of the highest-impact preventive care decisions for cats with outdoor access.