This gorilla’s caretakers are confronted with familiar questions about aging

This month, as the patient lay sedated on a table, a cardiologist made a half-inch incision through the skin of his chest. She removed a small implanted heart monitor with defective batteries and installed a new one.

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

Four neat sutures were required to close the incision. Within a few hours, the patient, a gorilla named Winston, would rejoin his family in their habitat at the San Diego Zoo Safari Park.

“At 51 years old, Winston is a very old male gorilla,” says Dr. Matt Kinney, a senior veterinarian at the San Diego Zoo Wildlife Alliance, who led the medical team through the procedure. With improved health care, new technology and better nutrition, “we’re seeing animals live longer, and they’re healthy longer,” he said.

In “human-managed care” (the term “captive” is no longer used in zoos) gorillas can live 20 years longer than the 30 to 40 year lifespan common in the wild, and longer than zoo gorillas did in recent decades .

However, like their human cousins, aging also brings with it chronic diseases that require testing, diagnosis and treatment. Gorillas are prone to heart disease, the leading cause of death for them and for us.

So now the questions for Winston’s caregivers are similar to those faced by doctors and elderly human patients: How much treatment is too much? What is the interaction between living longer and quality of life?

Geriatric wildlife care “has become increasingly sophisticated,” says Dr. Paul Calle, chief veterinarian of the Wildlife Conservation Society, based at the Bronx Zoo. “People’s medical and surgical knowledge can be applied directly.”

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

For example, Winston takes four common heart medications that people also use, albeit in different doses. (He weighs 451 pounds.) The heart monitor he was given, smaller than a flash drive, is also implanted in people. Winston got his annual flu shot this fall and is undergoing physical therapy for arthritis.

“We want to provide comfort to these animals later in life,” said Dr. Kinney.

That’s not cheap: There were nearly twenty 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, pays for Winston’s care through its annual operating budget. Donors and partners compensate some additional costs.

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

Some of Winston’s longtime caregivers, so-called wildlife care specialists, have retired. But Winston, who has achieved silverback status over the years, continues to work, leading his ‘troop’ of five gorillas, keeping the peace and intervening in arguments when necessary.

“He’s such a gentle silverback and an incredibly tolerant father,” said Jim Haigwood, the curator of mammals at the San Diego Zoo Safari Park. “His youngest daughter, he will still allow her to take food from his mouth.”

The zoo has twice introduced females with sons to the pride, which could lead to infanticide in the wild. But Winston’s caregivers believed he would accept it, and he did.

“He raised those little boys as if they were his own sons,” Mr Haigwood said. (However, when they became rambunctious teenagers, they were resettled in 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 robust health until 2017, when his caregivers noticed “a general slowdown,” said Dr. Kinney, who arranged Winston’s first echocardiogram.

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

In 2021, the entire troop group contracted the coronavirus, probably transmitted by a human. As with human patients, age mattered.

“Winston was the hardest hit,” said Dr. Kinney. “He had a cough, significant lethargy and loss of appetite.” As he walked, he started holding objects.

After an infusion of monoclonal antibodies, Winston recovered. Now the entire troop has been vaccinated and strengthened against the virus.

But while Winston was being treated, the vets and human doctors performed other tests that showed there were health problems. Winston’s heart began to pump less efficiently; that led to a daily regimen of blood pressure and heart medications hidden in his food, and to the implanted monitor. He also takes ibuprofen and acetaminophen for arthritis in his spine, hips and shoulders.

More worrying was a CT scan and biopsy that showed a cancerous tumor was damaging Winston’s right kidney. That led to the kind of risk-versus-benefit conversation that should drive decisions about invasive treatments for older patients, but is often left out for people.

“Are we doing a surgical procedure?” Dr. Kinney remembered wondering. “The big concern was: what would the recovery look like?” After considering Winston’s age and life expectancy and determining that the tumor was not growing, “we felt comfortable continuing to monitor him,” he said.

For now we have a good balance, he said. That is not entirely a medical issue, but reflects Winston’s ability to lead his troops – including a woman, Kami, with whom he has had a “very devout partnership” of 25 years, Mr Haigwood said.

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

Winston’s vegetarian diet consists mainly of tree branches and root vegetables. The half-acre Gorilla Forest where he lives, with its hills, pond and climbing structures, promotes exercise.

Yet geriatric care necessarily involves end-of-life decisions. Winston might one day die of natural causes Ozziea gorilla who died two years ago at the age of 61 at Zoo Atlanta, or Colourwho was 60 when he died in 2017 at the Columbus Zoo in Ohio.

But when his quality of life declines, when he stops interacting with the troops and his caretakers or begins to suffer, the parallels with human care end. Even in California, with its medical aid in dying law, euthanasia remains illegal for humans. It’s an option for Winston.

“It’s a privilege in veterinary medicine,” said Dr. Kinney. “It also comes with a great responsibility.”

If, after extensive discussion, Winston’s doctors, specialists and caregivers conclude that a painless death is preferable to a shortened life, “it’s a very peaceful process,” said Dr. Kinney. After an anesthesia overdose, he said, “there is cardiac arrest within minutes.”

About 350 gorillas — and a total of 930 great apes, including bonobos, orangutans and chimpanzees — live in U.S. zoos, Dr. Danforth said. No matter how well they are cared for, some animal rights activists and primatologists argue that they do not belong in zoos.

But even People for the Ethical Treatment of Animals, whose position is that wild animals belong in the wild, acknowledged in an email that zoos like San Diego’s, accredited by the Association of Zoos & Aquariums, meet high standards of field of animal care.

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

For now, “we want to make sure that Winston is living a good life, that he is fulfilled,” said Dr. Kinney. “We understand well what makes Winston Winston.”