Sheriff deputies were called to the Buck Brogoitti Animal Rescue in Pendleton after the chimp’s owner, Tamara Brogoitti, reported its escape and attack of her daughter, The Oregonian reported.
The chimp, named Buck, was shot and killed on-site, according to the Umatilla County Sheriff’s Office.
While Ms Brogoitti, 68, did not immediately respond to The Independent’s request for comment, Facebook posts showed Buck was about 16 or 17 years old and helped found their 800-acre namesake sanctuary.
She called the Sheriff about 8am on Sunday after Buck attacked her 50-year-old daughter, biting her in the torso, arms, and legs, and trapping her in the basement in need of medical attention, the Oregonian reported.
Authorities arrived and received Ms Brogoitti’s permission to fatally shoot the chimpanzee, who was shot in the head, to reach her daughter, according to Lieutenant Sterrin Ward.
Both women were taken to a local hospital for treatment.
The People for the Ethical Treatment of Animals (Peta) said in a statement they had warned state authorities that Buck was a dangerous ape and a "ticking time bomb" who had been deprived of the companionship of other chimpanzees for years.
"And now, he is dead and a woman has been mauled because of Brogoitti’s refusal to follow experts’ advice and transfer Buck to an accredited sanctuary," the statement said.
"It has been clear that attacks are inevitable so long as people continue to treat chimpanzees like Chihuahuas."
While it has been illegal to own chimps in Oregon since 2010, anyone who owned apes before that year was allowed to keep them.
Erika Fleury, program director at the North American Primate Sanctuary Alliance, told The Oregonian that attacks from primates in captivity should be expected as they’re not living natural lives where they can express natural urges and engage in natural behaviours.
“Having a non-human primate like a chimp or even a very small monkey living in a human home is harmful for the animal and can be very harmful for the humans as well,” she said.