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The world’s largest group of captive bonobos lives in Milwaukee. Sometimes, they break each other’s fingers. Dr. James Sanger is there to fix them.

Additional reporting by Daniel Simmons.

If Kitty had understood him, Dr. James Sanger would’ve offered some postoperative instructions.

Don’t bother bandaging the open wound that covers almost all of the bottom of your foot.

And by all means, lick the wound. A lot. Don’t spare the saliva.

Unorthodox advice? Yes. But Kitty was an unorthodox patient.

At the time of the surgery, she was in her late 50s or early 60s – birth records are somewhat murky – making her the oldest bonobo living in the United States, and likely the world. She came to Sanger because of an infected bite wound on her toe.

Kitty was also blind, nearly deaf and unable to place weight on her foot, which had a softball-sized bulge that nearly covered the heavily calloused sole.

“On her X-ray, this is a bad sign – there’s gas,” Sanger says, pointing to Kitty’s toe on film. “Bacteria are multiplying, and as a byproduct, they’re putting that out. Bacteria are going to start to get in the bloodstream.”

Sanger knows his stuff, and not just for bonobos. In fact, they’re not even his main patients. He’s a respected surgeon for humans, a professor at the Medical College of Wisconsin and chief of plastic surgery for the Zablocki Veterans Administration Medical Center. He even operated on Mayor Tom Barrett’s hand after it was broken in a bloody assault at the 2009 State Fair.

But for more than two decades, Sanger has also been on call for apes at the Milwaukee County Zoo, fixing mangled hands and feet that, left untreated, likely would spawn the serious consequences of an infection, possibly even death.

Sanger, in scrubs and a surgical mask, worked for an hour on the anesthetized Kitty’s foot, removing the calloused skin flap around the infected bulge and flushing the wound. It was red and raw and ghastly, but he left the wound unbandaged.

Long before treating Kitty, Sanger had been amazed to learn that animals have remarkable powers of self-healing, which enable them to recover within days from injuries that would lay up humans for weeks. One specific thing he’d learned about the hairy patients: Their saliva contains special wound-healing properties.

“In the wild, over millions of years, these animals have evolved a system that enables them to treat their injuries,” he says. “Humans have lost that. We have evolved a bit in the wrong way. We are not as tough.”

Kitty spent the days after surgery licking her wound. Sanger visited her daily, “making the rounds” as he would with a human patient. She recovered from the infection and rejoined her bonobo community.

“She was like everybody’s grandmother,” says Roberta Wallace, the zoo’s senior veterinarian. “So, when there was a lot of discord in the group and if somebody had to calm down, they’d go with Kitty, and she’d kind of make everything right.”

Sanger performed Kitty’s surgery back in 2011. When she died in 2013, it wasn’t because of the wound, but due to reasons associated more with her old age.

Photo by Adam Ryan Morris. Illustrations by Kevin Lawler.

Photo by Adam Ryan Morris. Illustrations by Kevin Lawler.


Milwaukee County Zoo houses 22 bonobos, which range in age from babies to nearly 50 years old. It’s the world’s largest captive community of this endangered species.

Bonobos, native to a stretch of riverside rainforest in the Democratic Republic of Congo, have gained fame and admiration among left-leaning humans because of their generally peaceful nature. They’re more social than their close cousins, the chimpanzees.

Yet politics also plays a role in the bonobo culture, from soap-opera-like dalliances to power plays for dominance.

In bonobo culture, the ladies wear the pants, unlike chimps, whose leadership is patriarchal. Bonobos are more likely to resolve their conflicts, often with sexual contact instead of aggression. They’re also known to have sex for non-reproductive reasons, which is rare among animals. Same-sex romance occurs, too.

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Yet the females who rule this realm are quick to mete out discipline if someone violates the group’s social mores. Steal a banana, take a length of fire hose that’s not yours or be generally insufferable, and expect swift justice from the ladies.

“The problem that gets us involved,” Sanger says, “tends to be the males that get frisky as they hit puberty. They start to annoy other bonobos. The women step in.”

The females separate the offending males from the others, then bite them around the butt. The lads put out their arms to protect themselves. Limbs collide with great force.

Lead bonobo keeper Stacy Whitaker tries to prevent altercations that lead to fights by mixing and matching small groups of the bonobos in different quarters throughout the day. Like a playground monitor, she makes sure to separate those who don’t get along, and is quick to sense potential trouble.

But faceoffs still occur. “They have their cliques, and some days, you have a spat,” she says.

And when those spats result in serious injuries, Sanger is waiting on call, an esteemed surgeon eager to beeline for volunteer duty at the zoo.


Sanger first joined the zoo’s volunteer crew after being recruited by Dr. Frank Begun, a urologist who had worked with zoo staff on a sperm harvesting project involving Samson, the zoo’s legendary gorilla.

Begun knew that Sanger majored in zoology at the University of Michigan before embarking on his medical career, and saw a need for a specialist who dealt strictly with hands and feet. And since bonobos’ anatomies have similarities to humans’, treatment of their ailments or infections translates, too.

Over the years, Sanger has operated about five times on bonobos, examined others, and performed hand surgery on a gorilla and an orangutan.

The orangutan was one of his earliest patients, arriving on his operating table with broken fingers. It was back in the early 1990s, but zookeepers still enjoy the memory of Sanger, fully scrubbed in, dashing out of the operating room when the anesthetized patient made a small movement during surgery.

“I was out of there. They were all laughing,” says Sanger.

He later learned there had been no danger. But his freak-out had some merit. Orangutans are incredibly strong – some can swat a man across the room as easily as if they were swatting a tennis ball across a net.

Sanger relies heavily on the zookeepers, who have earned the bonobos’ trust only after years of working with them. The animals can be coaxed to hold out a hand or foot for inspection, or to volunteer their shoulder for a shot – but only for their longtime caregivers. When the patient is a dominant female bonobo, her protector males will take on threatening stances and threaten to soak Sanger with urine, if not for the keepers’ intervention.

In his experience, it’s “like treating little children,” Sanger explains. “They are not going to cooperate.”

Handlers often take a wait-and-see approach when dealing with injuries unless there’s potential for a deadly infection. And while the zoo’s veterinarian will call Sanger for a consult, in the end, the vet has the final decision on courses of treatment.

“We give them our best recommendation based on our experience almost exclusively in humans,” Sanger says. “We tell them what could be done. This can be quite different than what should be done.

“They consider much more and make their decision on what is best for the animal overall.”


Magi, a silverback gorilla, had cut one or two tendons that are crucial to stabilizing the wrist for knuckle-walking. But just getting close enough to Magi to examine his hand was a delicate process led by his keeper. Sanger sat on an egg crate across the room from Magi’s cage. The keeper, Claire Richard, sat with her back against the cage. Magi followed suit, sitting with his back to the keeper.

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“This is the ultimate show of trust. This is the bond with him and Claire,” Sanger says, obviously impressed by it. “This was the first time I had ever been this close to a gorilla that was awake.”

Gradually, Sanger moved closer to Magi as Richard talked in soothing tones to the gorilla. She was then able to coax Magi to hold out his injured hand for inspection.

Ultimately, Sanger determined one tendon was likely working, which could compensate for the damaged tendons as they healed. The vets decided to delay treatment and observe the animal over the coming weeks.

Within the primates’ world, social structure and familial relationships play a large role in determining the best treatment. “If you take some animals out of their family group for an extended length of time, you’re never going to reintegrate into it,” says Wallace, the zoo’s senior veterinarian. “Their family isn’t necessarily welcoming them home with open arms; somebody else has jostled for the top.”

In fact, had Magi been removed from his group, upon his return, another gorilla that was second-in-command could very well have tried to kill him in a fight for dominance. So it was a good decision, Sanger says. “The animal recovered enough function that we never operated.”

The hands-off approach similarly worked with Makanza, a young bonobo male who one day displayed a finger that had been pulled backward and appeared out of joint. His keepers didn’t see how the injury occurred, but believe he’d been disciplined by a female.

After consulting with Sanger, the handlers watched Makanza for a few days, noting he could still use his hands to cling to branches and eat. Meanwhile, Makanza and the females resolved their flap. One of them was later observed cleaning his wound. Today, two of Makanza’s fingers remain crossed but no intervention was necessary.


Now contemplating retirement, Sanger has been doing fewer operations at the zoo and serving more as a medical liaison, helping the zoo connect with other specialists as needed. He sees it as a small way to keep assisting the zoo in one of its missions: educating the public about bonobos, which are threatened with extinction. In their native Congo in central Africa, their numbers have declined due to deforestation, poaching and civil war.

But even though Sanger’s history with the zoo has been focused on the primate population, he’s well aware of what goes on elsewhere at the institution. He says he has it easy compared to zoo veterinarians, whose patient roster includes an arthritic giraffe, some bats with dental problems and a turtle with bladder stones. And he’s far from the only doctor of the human-treating variety with whom zoo vets have worked. They’ve sought help from a cardiologist, an obstetrician-gynecologist, even a psychiatrist, who helped a bonobo named Brian overcome emotional problems that had alienated him from others.

In all, the vets work with 220 different species, not including the fish, and Sanger professes awe for their work. “I keep threatening,” he says, “to come over here and shadow them when I retire.”

Lisa Black is freelance writer and Daniel Simmons is a senior editor at Milwaukee Magazine. Write to them at letters@milwaukeemag.com.

Tune in to WUWM’s “Lake Effect” March 16 at 10 a.m.  to hear more about  this story.

‘Giving Bonobos a Hand’ appears in the March 2016 issue of Milwaukee Magazine.

Find the March issue on newsstands beginning Feb. 29.

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