Despite the RSPCA’s efforts, vivisection continued, and cats and dogs became ever more popular research subjects, especially with the rapid growth of the scientific enterprise that followed World War II. Long before companies began mass breeding mice, rats, and other creatures for research, dogs and cats were the guinea pigs of choice. At first, the public didn’t bat an eye—even when, beginning in 1948, the biomedical research lobby helped push through legislation in several states that required animal shelters to surrender their unclaimed cats and dogs to hospitals, universities, and pharmaceutical companies. But when thieves known as bunchers began stealing pets from people’s homes, and Americans began to get wind of animal dealers who chained up and caged dogs and cats in horrendous conditions as they waited to be sold for biomedical research (a 1966 Life magazine exposé about an especially notorious Maryland animal dealer was entitled “Concentration Camps for Dogs”), the public put its foot down. It flooded Congress with tens of thousands of letters, eclipsing the number received on Vietnam and civil rights issues combined.