Proponents of animal testing argue that there is no adequate and ethical alternative to testing on a living, nonhuman whole-body system, pointing out that the process is highly regulated and that animal testing has contributed to scientific and medical breakthroughs. Others argue that animal testing is cruel, inhumane and unnecessary, producing drugs that may not be safe for human use.
The practice of animal testing dates back to 500 B.C., with an estimated 26 million animals used in the United States yearly, as of 2014. Animal testing is used to check the safety of products intended for human use. It is regulated by the Animal Welfare Act, which covers many but not all of the animals used for research, including reptiles and mammals bred specifically for testing. There is no regulation of the experiments, only of the animals' housing and transportation.
Animal testing is a controversial topic in the United States. The initial catalyst for the controversy traces back to a 1965 Sports Illustrated article about a kidnapped family pet sold into experimentation where it died. Some opponents explicitly compare "speciesism" with racism and sexism. In 2013, the U.S. National Institutes of Health announced that chimpanzees would no longer be used in experiments, which was met with mixed reactions by critics who pointed out the deleterious effects the ban would have on vaccine research.