Kyah had an extra blood vessel wrapped around her esophagus — a symptom of a congenital heart defect — that prevented her from holding down solid food.
The surgery took place at Oklahoma State University's Veterinary Medical Hospital. Zoo veterinarian Dr. Gretchen Cole said before the surgery that, at best, Kyah had a 50 percent chance of survival.
Zoo spokeswoman Candice Rennels said Kyah was euthanized during surgery when surgeons realized she would not overcome complications.
"The zoo family is grateful to our colleagues at OSU's Veterinary Medical Hospital for their expertise and hard work," said Dr. Jennifer D'Agostino, zoo director of veterinary services. "We knew going into this procedure that Kyah's chances were extremely low and we felt we gave her every chance possible to thrive. Collaborations such as these also allow us to learn more about the species in our care."
The 4-hour surgery was performed to treat what zoo veterinarians believed was a persistent right aortic arch, a problem often found in dogs and cats.
OSU veterinary surgeon Mark Rochat performed the surgery and has previously performed about a dozen similar surgeries on smaller animals such as dogs, cats and a cougar. He was assisted by other veterinary surgeons as well as the zoo's five-person veterinary team.
This was the first attempt of this procedure on a giraffe, and without it Kyah would have had no chance of survival, Cole said.
Kyah, described by zookeepers as feisty and mischievous, didn't appear sick to visitors. At 6-months-old she was nearly 8 feet tall and weighed 525 pounds.
Keepers first noticed a problem when Kyah began regurgitating her mother's milk after nursing at was 6 weeks old. The problem got worse as she transitioned to solid food.
A routine necropsy will be performed, as is standard protocol when animals at accredited zoos in the U.S. die. After, the giraffe's tissue will be used for research purposes at Oklahoma State University and the University of Oklahoma.
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