Animal Welfare Act Timeline.

1966: Congress passes the Laboratory Animal Welfare Act to regulate the care and handling of dogs, cats, non-human primates, guinea pigs, hamsters, and rabbits at licensed research institutions and animal dealer facilities.
1970: The act was, with certain exceptions, expanded to cover all warm-blooded animals in research as well as to cover animals in circuses, zoos, roadside shows, and commercial breeding operations. It was rechristened the Animal Welfare Act.
1976: Congress approved amendments to the act to cover animals in transportation as well as those forced to fight.
1985: Congress passed amendments requiring the use of pain killers and presurgical and postsurgical care; animal care training for personnel who work with animals; and euthanasia of an animal upon completion of an experiment. The amendments, among other things, also required exercise for dogs and a physical environment to promote the psychological well being of nonhuman primates.
1990: Congress passed amendments that imposed longer holding period requirements upon animal dealers.
2002: U.S. lawmakers, as part of the Farm Bill, passed an amendment that closed loopholes in the federal ban on the interstate shipment and foreign export of fighting animals. Congress also passed an amendment that codified into law the USDA’s long-standing exclusion of birds, mice, and rats from coverage as research animals.