Is cancer contagious? Only a few years ago, most doctors would have answered this question with an emphatic "No!" Now their replies are likely to be less dogmatic. Researchers have long suspected that cancer viruses can be passed genetically from parents to offspring in both animals and humans. A team of veterinarians and cancer researchers headed by Dr. William D. Hardy Jr., 33, of New York's Memorial Sloan-Kettering Cancer Center, has just reported in Nature that among cats, at least, one animal can infect another with the virus that causes leukemia.
Feline leukemia virus (FeLV) was first identified in 1964 by a...