KANSAS CITY, Mo. —

The Kansas City Zoo announced via press release that one of their western lowland gorillas recently had the delta variant of COVID-19.

The other five gorillas that make up the zoo’s troop, are presumed to also be positive. The zoo has yet to receive official test results.

While all the gorillas have shown symptoms of the virus, some have already returned to normal. The zoo says the rest of the troop continue to respond to treatment and are improving.

The gorillas’ care specialists first noticed that Charlie the gorilla did not appear to be feeling well on Sept. 22 and then began coughing on Sept. 25.

The zoo says the veterinary health team immediately began treatment but within the next several days other gorillas began showing symptoms. Coughing and a lack of appetite are among many outward symptoms the animals began displaying.

Related video: COVID-19 spreads through gorillas at zoo in Atlanta

All of the gorillas are scheduled for the Zoetis vaccine, which was specifically developed for use with animals. The zoo says research has shown the vaccine to be safe.

"As always, the top priority of the Kansas City Zoo is the health and safety of our animals, guests, and staff. As the COVID-19 pandemic progressed, the zoo implemented protocols to keep susceptible animals and their caregivers safe," The KC Zoo said in their press release.

The zoo doesn't know how the gorillas came down with virus. They also say that visitors to the KC Zoo are not at risk of contracting COVID-19, due to the viewing distance and design of their gorilla habitat.

KANSAS CITY, MO — A rare and innovative procedure at the Kansas City Zoo saved the life of one of their resident gorillas.

Zoo staff says it was truly a team effort and one that will go down in the record books. It was only the seventh time in the world that a gorilla-to-gorilla blood transfusion had been performed.

It all started in the spring when zoo staff noticed one of their two male gorillas, Curtis, wasn't acting like himself.

"They noticed he wasn't eating as well, and he was kind of hunched over every now and then and seemed like he might have some abdominal discomfort," veterinarian Kirk Suedmeyer said.

A basic exam indicated the great ape was anemic or losing blood, but zoo staff didn't know why.

The only way to tell for sure was to do a CT scan, but that's one diagnostic tool the zoo doesn't have. So, they had to anesthetize him, put him in the back of a van, and transport him to a human imaging facility more than 30 minutes away.

"Yes, we do go through the side door, and the room is not scheduled for a human patient. And it is thoroughly cleaned after we're there," Suedmeyer said.

Kansas City Zoo

The scan they performed there showed Curtis had a large hemorrhage, or blood clot, in his abdomen, along with another hemorrhage in his left kidney.

His situation was life-threatening, and Curtis' options were limited.

"You cannot transfuse human blood into a great ape and vice versa," Suedmeyer said. 'They have different blood groups than we do, and we do not have a gorilla blood bank."

But, the zoo did have a suitable match in his younger brother, Charlie. So, in an innovative and extremely rare procedure, they performed a gorilla-to-gorilla blood transfusion.

The entire procedure from start to finish took about 14 hours, and Curtis received 10 bags of blood — almost half a gallon.

Thankfully, between the blood transfusion and medications used to contain the hemorrhage, the procedure was a success, saving Curtis' life.

Curtis spent time in recovery, during which he was closely monitored, and 60 days later, he was ready to return to the gorilla exhibit, much to the apparent relief of Charlie.

"He definitely seemed like he missed him quite a bit," said Kansas City Zoo animal care manager Josh Murray. "That was the first time they've ever been a part, really, for an extended period. So, after 25 years, I think he was just feeling a bit lonely."

Murray added that in the wild, two adult male apes would not live in the same troop. But, Charlie and Curtis, both in their mid-20s, are brothers who've grown up together in captivity. They spent time at the Denver Zoo before being transferred to Kansas City.

Though they're glad to be back together, did Curtis show Charlie just how much he appreciated his brother's life-saving gift?

"I don't think there's a lot of hugging and thanking and 'thank you; I owe you my life.' I don't think that occurred, no," Suedmeyer said with a laugh.

Although Charlie and Curtis don't understand the significance of what the zoo was able to do, staff members certainly do. They say they're thrilled this turned out to be an animal tale with a happy ending.

This story was originally published by Caitlin Knute on Scripps station KSHB in Kansas City, Missouri.