Feline leukemia virus (FeLV) is a leading cause of cancer and immune suppression in cats. Prevention through vaccination and testing is highly effective.
FeLV-positive cats face significant welfare challenges including susceptibility to secondary infections and cancer. The prognosis has improved with modern supportive care, but cats still experience considerable suffering from the disease and its complications. Early detection through testing allows owners to make informed management decisions and protect other cats in the household. The welfare of FeLV-positive cats depends on minimizing stress, preventing secondary infections, and monitoring for early signs of disease progression. Euthanasia should be considered when quality of life cannot be maintained.