Gus, a polar bear at the Central Park Zoo, swam ceaselessly. He’d dive into his pool, slither across the bottom, surge to the surface, and backstroke to the other side. Then, he’d tuck his head into the water and do it again. And again. And again. Twelve hours a day. Every day. Gus was New York’s woolliest neurotic. And when the tabloids got hold of his story in the mid-1990s, it took off. David Letterman cracked wise. The rock band The Tragically Hip asked, “What’s Troubling Gus?” And the $25,000 the zoo spent on an animal behaviorist became a national punchline.

But a couple of decades later, the joke has lost a bit of its zing. Gus’s compulsive behavior, a growing pile of research suggests, is distressingly common among captive animals. The gorillas behind the glass are plucking their hair, and the orangutans are incessantly masturbating. Dolphins ram their heads into the sides of pools, and sea lion pups try to nurse from each other instead of adult females.


It happens so much, it’s got a name: “zoochosis.” And it’s not just the zookeeper who’s implicated. Some of our household pets are exhibiting worrisome signs of mental illness, too — Doberman Pinschers sucking their flanks and cats licking themselves so much they wear the fur away. (See sidebar.)

Growing unease with this “stereotypic” behavior, as it’s called, has helped fuel a $42 billion animal pharmaceutical industry. Fluoxetine, the generic form of Prozac, now comes in dozens of pet-friendly flavors, including peanut butter, apple and molasses, double grape, double liver, double beef, double fish, and — for the especially carnivorous depressive — triple fish. Animals are taking Xanax, Klonopin, Zoloft, Buspar, Ativan, and Paxil, too.

Haldol, an anti-psychotic, has been used to ease red-necked wallabies into captivity, Laurel Braitman reports in her book “Animal Madness,” and to dampen a black bear cub’s separation anxiety when she was moved to a cage of her own.


Captivity can be good for an animal’s physical health, since it means higher-caloric meals and, often, longer life spans. And zookeepers resist the idea that there is a mental health crisis in their midst; the overwhelming majority in their care are quite happy, they say. But a wave of multi-million dollar zoo overhauls designed to improve animal welfare suggests at least some level of concern. The Philadelphia Zoo, the nation’s oldest, has installed a network of meshed-in pathways that allow gorillas, Siberian tigers, and saki monkeys to roam the campus — sometimes pausing to gaze at the humans strolling below. And a couple of years ago, the Sedgwick County Zoo in Wichita, Kansas, opened a 5-acre elephant habitat accessible by boat.

Then there is Zootopia, a planned expansion of Denmark’s Givskud Zoo. Designed by architectural phenom Bjarke Ingels, the 300-acre project aims to invert the relationship of visitor and animal — concealing the humans in wood piles, bamboo thickets, and mirrored pods while the lions, giraffes, and zebras wander multi-species habitats.

But even zootopias have walls. “The major flaw in all of these zoos and sanctuaries and refuges,” acknowledges Jon Coe, perhaps the world’s foremost zoo designer, “is that animal management is determined by coercion and captivity.”

And just as we’ve insisted, in recent decades, on a more balanced understanding of human health — one that puts mental health on par with physical well-being — it may be time, animal behaviorists say, to take animal anxiety and depression more seriously. Are Prozac and mirrored pods enough to keep the animals from going crazy, they ask, or is something more required — something like a radical reinvention of animal captivity?


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FOR MUCH OF human history, we took a rather dim view of animal consciousness. Brutes do not think, the French philosopher Rene Descartes declared in 1649.

Yet Charles Darwin, whose theory of evolution suggested humans are just another animal, broke with the earlier view. In his 1872 treatise “On the Expression of the Emotions in Man and Animals,” Darwin made an explicit link between the emotional experiences of both — calling the similarities further proof that we shared common ancestors. Darwin identified disgust in chimps, dejection in dogs, and grief in elephants.

That sort of anthropomorphism is generally frowned upon, now, in scientific circles. But keeping too much distance, Braitman argues in “Animal Madness,” can blunt our understanding of animals’ inner lives. The trick, she says, is to “anthropomorphize well,” rejecting “self-centered projection,” even as we recognize “bits and pieces of our human selves in other animals and vice versa.”

A spate of recent studies shows animals are far more like us — far more self-aware and socially sophisticated — than previously imagined. Elephants and magpies recognize themselves in mirrors. Laboratory rats spring trapped, anxious cagemates, even it means sharing their own chocolate. And chimpanzees will help each other without expecting anything in return. Nonhuman animals “have very rich internal lives,” says computational neuroscientist Philip Low, “and we should not mistake our inability to decipher them with some sort of vacuity on their side.”


But once we accept the richness of those internal lives, and confront our role in disturbing them, we face some thorny questions about what to do.

Nicholas Dodman is an advocate for drugs. His adventures in animal psychopharmacology began in earnest in the 1980s, with a study of a compulsive behavior known as “cribbing” — horses biting down on their stall doors as many as 600 times an hour, arching their necks, and grunting. Dodman and a partner found that they could eliminate it entirely by administering Narcan, an overdose-reversal drug that blocks the stress-induced endorphins that may fuel cribbing.

When they cured a Palomino named Poker’s Queen Bee, he says, the owner was so moved that she quit her high-powered job and got a PhD in biochemistry. Dodman’s own career — he’d focused on anesthesiology up until that point — changed course, too. He founded the Animal Behavior Clinic at Tufts University and went on to study what looked like animal analogues of obsessive-compulsive disorder, autism, and self-mutilation. He became a sort of evangelist for the use of pharmaceuticals to treat them.

He was enthralled by the science — by the curative powers of the medications. But he also saw a moral duty at play. “If you take a big cat, and you put it in an exhibit, and it starts to express a compulsive order that you have induced,” says Dodman, now a professor emeritus at Tufts, then you’re obligated to administer powerful drugs if they will help.


Yet the better option, he says, is to eliminate zoos altogether — or at least, to remove the live animals from them. Let visitors strap on virtual reality goggles, he says, walk from exhibit to exhibit, and see the animals in their natural habitats: “Look at gorillas actually being gorillas, look at giraffes actually being giraffes.”

Coe, the zoo designer, sees a future in virtual reality, too. But the desire to see an animal in the flesh, he says, is likely to remain strong. And the best way to fulfill that desire while protecting the mental health of animals, he argues, is to embrace what he calls an “unzoo” approach, with the free-ranging animal at its center.

Coe is a big fan of whale watches and swims with wild dolphins. And in China, he developed a master plan for a wildlife park — never built — that would have used food grown by local farmers to lure a remarkable mountain goat-like creature called the takin into a valley where tourists could watch them from buses.

Here in Boston, he says, families should be taking guided tours of the Fens, learning about the waterfowl and turtles native to the area.

The first generation of conservation involved fencing in national parks, Coe says. In the second, the goal was restoring wetlands and putting sanctuary-raised endangered species back in the wild. The next phase, he says, is accommodation — making room for the wildlife in our midst and lowering the remaining boundaries between nature and civilization.

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JOHN LINEHAN ISN’T ready to give up on the traditional zoo yet. As a child, he visited the Stone Zoo in Stoneham with his grandparents — somehow, he got it in his head that his grandfather owned the place. And he’d head up to Boston, sometimes, with friends to poke around Franklin Park Zoo.

His memories from that period aren’t all that pleasant — small, dark cages and pacing lions. But Stone and Franklin, which he now oversees as president and CEO of Zoo New England, have changed a lot in the last 50 years. Zoos throughout the West have changed. The exhibit spaces are larger and more naturalistic, and the staff is far more professional. Many are involved in the conservation of endangered animals.

Linehan has seen some of the stereotypic behavior that worries researchers and advocates — one of the gorillas he’s worked with for years, Little Joe, is a hair plucker. But this sort of repetitive conduct is not as disturbing as critics make it out to be, he says. Sometimes it’s behavior left over from an abusive situation that predates the animal’s time in the zoo; and sometimes it’s anticipatory behavior — pacing back and forth at the sound of approaching staff, for instance.

Ninety-nine percent of the animals in his zoos are happy, Linehan says. And there is real magic in exposing generations of children to them. “You really need to reach their heart to get them to care,” Linehan says. “Then they’re passionate.”

It’s a refrain you’ll hear from a lot of zookeepers. And the Association of Zoos & Aquariums released a study in 2007 trumpeting just that kind of educational impact.

More recent research has cast doubt on the argument. A team of Emory University researchers who examined the AZA study found its results inflated, and concluded that “there is no compelling or even particularly suggestive evidence for the claim that zoos and aquariums promote attitude change, education, and interest in conservation in their visitors.”

Regardless, they’re popular. Many zoos are experiencing record attendance, and it’s hard to see them going away anytime soon. In the short term, it is zoos that will have to drive improvements in the mental health of captive animals. That could mean more of the sort of meshed-in pathways that have gone up at the Philadelphia Zoo. And zoos with smaller footprints may have to relinquish animals, like elephants, in need of more space. Some already have.

It will also require a continued focus on the needs of individual animals. Remember that animal behaviorist who was brought in to work with Gus, the Central Park Zoo polar bear, at a cost of $25,000? He actually had some success.

Gus was made to forage for meals, pulling chicken from a rawhide wrapper and coaxing a frozen mackerel out of a block of ice. He got a redesigned habitat and a bunch of new playthings, The New York Times reported, including traffic cones and rubber garbage cans. And in time, his compulsive swimming tailed off. Gus seemed happier. More himself.

But even at the end of his life, there were days when the polar bear would inexplicably plunge into the water in a riot of bubbles, surge across the pool, turn back, and do it again. And again. And again.

Whatever his human masters did for poor Gus, life as a Manhattanite never sat quite right.

David Scharfenberg can be reached at david.scharfenberg@globe.com. Follow him on Twitter @dscharfGlobe