She co-founded PETA, the largest animal rights organization in the world, in 1980. Far further afield than most of its members, Newkirk calls for the abolition of all "animal slavery," including livestock, pets, zoos, seeing-eye animals, police and rescue dogs, etc.
Newkirk is heavily opposed to the fur trade, and in her will she has donated her skin to be used to make wallets after her death as a protest against the leather trade. She has objected to the use of donkeys as suicide bombers and wrote a protest letter to Palestinian leader Yasser Arafat on this issue.
She is also opposed to all forms of animal testing, including medical testing as well as testing of cosmetics on animals. It's unknown whether she is as vehemently opposed to the testing of insulin on animals, as her vice president, Beth Sweetland, is diabetic and regularly takes insulin injections.