By Dr. Amy Plankenhorn
Feline leukemia virus (FELV) was recognized as a serious infectious disease of cats in the late 1960s, and by the 1970s blood testing for the disease was widely available. Until fairly recently, FELV-related tumors were the most common cancers in cats. Fortunately, the development of safe and effective vaccines for FELV has reduced the frequency and risk for the disease in our domestic cat population. The bad news is that there are plenty of unvaccinated outdoor cats who are still spreading and carrying this incurable disease.