(Reuters) – Pat Derby, a show business animal trainer who worked on the television programs “Flipper” and “Lassie” before becoming an animal rights activist, has died of throat cancer, her organization said.

Derby, 69, worked on other television shows, including “Gunsmoke” and “Daktari”, according to the Performing Animal Welfare Society or PAWS. She was the trainer and spokesperson for the Lincoln Mercury “Sign of the Cat” cougars Chauncey and Christopher, featured in ads.

Those were among the memorable TV shows and ads of the 1960s and ’70s, along with “Flipper”, starring a bottlenose dolphin from 1964 to 1967, and “Lassie”, starring a series of collie dogs from 1954 to 1974.

Derby became shocked at the neglect and abuse she found in the performing animals business. Her autobiography, “The Lady and Her Tiger” in 1976, was an expose on the harsh treatment of animals in the entertainment industry, according to PAWS.

Along with her longtime partner Ed Stewart, Derby founded PAWS in 1984 to rescue and provide humane sanctuary for animals from the exotic and performing animal trades.

With Stewart by her side, Derby died on Friday at her home in San Andreas, California, outside Sacramento, PAWS said in a statement dated Saturday and made available to Reuters on Monday.

“She was the first to champion the cause of performing animals, and today, because of her tireless work, and fierce determination, most animal protection organizations now have captive wildlife programs that address the issues of performing animals,” PAWS said.

Derby testified before Congress twice and served on several state committees setting standards for the care and handling of elephants and other exotic species, PAWS said.

PAWS said it maintains three sanctuaries for captive wildlife in northern California, providing refuge for more than 100 animals, including elephants, lions, tigers, bears, bobcats, coyotes, leopards, mountain lions, deer and monkeys.