The oldest known gorilla living in a zoo, a female named Colo, is slated to undergo a surgical biopsy sometime before her 60th birthday on Dec. 22.
The Columbus Zoo and Aquarium in Ohio says veterinarians have been monitoring a mass under Colo's arm since summer and it recently changed and started causing her discomfort, so they want to take tissue samples to determine the cause and possible treatment. She'll also get a thorough medical check-up.
The procedure involves anesthesia, making it more risky, but zoo officials said they're cautiously optimistic that they'll be celebrating with her on her birthday.
"We weighed the decision carefully and decided the risk would be greater if we did not examine her, especially if the biopsy finds that she has a treatable condition," Dr. Randy Junge, the zoo's vice president of animal health, said in a statement.
President and CEO Tom Stalf said the zoo wants to keep Colo around as long as it can, with her wellbeing in mind. She already has exceeded the usual life expectancy by two decades.
"We have had the privilege of caring for her from her first breath, and we take our responsibility very seriously to help her live a life that is as long and healthy as possible," Stalf said. "At her advanced age, every day we have with her is a gift."
Colo will remain off public exhibit while she is observed around the clock after the surgery, the zoo said.
Colo's birth in 1956 made her the first gorilla born in a zoo. Officials say she is one of about 350 western lowland gorillas living in zoos accredited by the by the Association of Zoos and Aquariums.
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