Gorilla makes caregivers face treatment dilemma – 12/28/2023 – Science

This month, while the patient was anesthetized on a table, a cardiologist made an incision just over a centimeter long in his chest. She removed a small heart monitor that had low batteries and implanted a new one.

The patient, like many older men, had been diagnosed with heart disease; the monitor would provide continuous data on heart rate and rhythm, alerting his doctors to irregularities.

Closing the incision required four stitches. In a few hours, the patient, a gorilla named Winston, would rejoin his family at the San Diego Zoo Safari Park in the United States.

“Winston, at 51 years old, is a very old male gorilla,” said Matt Kinney, a senior veterinarian at the San Diego Zoo Wildlife Alliance who led the medical team during the procedure. With improved healthcare, new technology and better nutrition, “we see animals living longer and also healthier for longer,” he added.

In “human managed care” (the term “in captivity” is no longer used in zoos), gorillas can live two decades beyond the 30 to 40 year life expectancy that is common in the wild, and also longer than zoo gorillas lived decades ago.

Just as with humans, however, aging also brings chronic diseases that require testing, diagnosis and treatment. Gorillas often develop heart disease, the leading cause of death for both them and us.

Now the questions for Winston’s caregivers resemble those facing doctors and older human patients: How much treatment is too much? What is the trade-off between prolonged life and quality of life?

Geriatric wildlife care has become increasingly sophisticated, according to Paul Calle, chief veterinarian at the Wildlife Conservation Society, based at the Bronx Zoo in New York City. “People’s medical and surgical knowledge can be directly applied.”

It feels more like human geriatric care. To keep the gorillas healthy, the zoo’s veterinarians not only turn to technologies and medicines developed for humans, but also consult medical experts such as cardiologists, radiologists, obstetricians and dentists.

Winston, for example, takes four common heart medications that people take, albeit in different dosages. (He weighs 200 kilos) The heart monitor he received, smaller than a flash drive, is also implanted in humans. Winston received his annual flu shot in the fall and is undergoing physical therapy for arthritis.

“We’re looking to provide comfort to these animals at the end of their lives,” Kinney said.

That’s not cheap: There were nearly 20 doctors, technicians and other staff in the operating room when Winston received his new monitor. But the San Diego Zoo Wildlife Alliance, the zoo and safari park’s parent organization, covers Winston’s care through its annual operating budget. Donors and partners offset some additional expenses.

“None of our animals have health insurance and they never pay their bills,” Kinney noted.

Several of Winston’s longtime caregivers, called wildlife care specialists, have retired. But Winston, who has achieved dominant male status with age, stays on the job, managing his “pack” of five gorillas, keeping the peace and intervening in fights when necessary.

“He’s so gentle, an incredibly tolerant father,” said Jim Haigwood, curator of mammals at the San Diego Zoo Safari Park. “He even allows his youngest daughter to take food from his mouth.”

The zoo twice introduced females with offspring into the pride, which in the wild could lead to infanticide. But Winston’s caregivers believed he would be acceptable, and he was.

“He raised these males as if they were his own children,” Haigwood said. (Once they became excitable teenagers, however, they were relocated to their own habitat, an option that human parents might occasionally envy.)

Winston, a western lowland gorilla native to Central Africa, arrived at the San Diego Zoo in 1984. He enjoyed good health until 2017, when his keepers noticed “a general slowdown,” said Kinney, who organized the Winston’s first echocardiogram.

The test showed only “a few subtle changes, nothing alarming,” Kinney said. Everyone was relieved. Normal aging.

Then, in 2021, the entire group contracted the coronavirus, likely transmitted by a human. As with human patients, age mattered.

“Winston was hit the hardest,” Kinney said. “He had a cough, significant lethargy, lack of appetite.” The gorilla began to lean on objects as he walked.

After an infusion of monoclonal antibodies, Winston recovered. Now, the entire group has been vaccinated and received a booster against the virus.

But while Winston was being treated, veterinarians and human doctors performed other tests that identified concerning health issues. Winston’s heart began to pump less efficiently. This led to daily blood pressure and heart medications, hidden in his food, and the implanted monitor. He also takes ibuprofen and acetaminophen for arthritis in his spine, hips and shoulders.

More concerning was a CT scan and biopsy that showed a cancerous tumor damaging Winston’s right kidney. The diagnosis resulted in a conversation about risks versus benefits to evaluate decisions about invasive treatment in older patients — a conversation that is often ignored for humans.

Some aspects of healthy aging may be easier for zoo primates than for people; their caregivers only offer healthy choices. “They don’t smoke,” said Marietta Danforth, director of the Great Ape Heart Project, a research effort at the Detroit Zoo. “They don’t eat cheeseburgers.”

If Winston’s doctors, specialists and caregivers conclude, after extensive discussion, that a painless death is the best decision, “it will be a very smooth process,” Kinney said. After an overdose of anesthesia, “within a matter of minutes, cardiorespiratory arrest occurs,” he explained.

Winston had high-quality years, Kinney said. The gorilla has also become a beloved media personality. San Diego will mourn his loss, whenever and however it happens.

For now, “we want to make sure that Winston is living a good life, that he’s fulfilled,” Kinney said. “We have a good understanding of what makes Winston Winston.”