In Tasmania, there are some wallabies that just can't control themselves: They hop the fence and get stoned on poppy sap, sometimes until they pass out in the field, are found in the morning and carried away.
Off California, young male sea otters frolic in waters where no other otters dare to go – with great white sharks in an area of the Pacific Ocean that researchers called the Triangle of Death.
And there are female pigs who starve themselves, to death at times; a prevailing theory is that the fatter sows are bullying their more timid, anxious pen-mates, leading to thin-sow syndrome.
Addiction, anorexia, teenage risk-taking – attach the above examples to a certain two-legged mammal with a high-end brain, and the story is remarkably similar. You have only to look in a veterinarian's medicine cabinet, stocked with the same antibiotics and antidepressants as the Shoppers Drug Mart down the street, to recognize nature's truism: We're all animals. In fact, pharmaceutical companies have grown a fine business based on the idea that human beings and our furry companions tend to get sick in many of the same ways.
The problem, raised in a new book called Zoobiquity, is that the medical community, cemented by some pretty rigid hierarchy, is failing to see the (depressed) monkey for the jungle. If we want to be cured of everything from cancer to depression, perhaps physicians should talk to the animals. And, more precisely, to their doctors.
Before the turn of the century, particularly in small rural towns, the doctor who helped to bring the human kids into the world was likely to be doing double duty with the foals in the horse barns. But then cities replaced farms, and medicine became more professional and specialized, and, with few exception, physicians and veterinarians parted ways.
"Physicians can be really condescending about recognizing vets as their clinical peers," says cardiologist Barbara Natterson-Horowitz, who co-wrote the book with science writer Kathryn Bowers and coined the term "zoobiquity" to refer to a species-sweeping approach to medicine. "And that's wrong because, in many ways, they have a much harder job."
The most obvious: Dogs and cats can't explain when the pain started. (To be fair, she points out, animal doctors have an inside joke of their own: What do you call a vet who treats only one species? A physician.)
Dr. Natterson-Horowitz first realized how this thinking may be impeding the practice of innovative medicine in 2005, when the chief veterinarian at the Los Angeles Zoo asked her to consult on a case involving an emperor tamarin with heart failure. Hoping to bond a little before starting her exam, she stared into the petite primate's eye. The vet asked her to stop: The stare could be interpreted as a threat and spark a reaction called "capture myopathy," a physiological fear in which adrenalin is pumped quickly to the heart, potentially causing damage.
Back at her office, Dr. Natterson-Horowitz researched the diagnosis, and found a human version of the phenomenon first identified in a peer-reviewed journal in 2000. It was "trumpeted" she says, "as a new diagnosis," but veterinarians had been writing about it for decades.
"If I am just accidentally discovering this by hanging about veterinarians, what other information do veterinarians have that could benefit human beings?" she asks.
Working with Ms. Bower, she began to chart the human diseases that also afflict animals. Killer whales get Hodgkin's lymphoma. Koalas get chlamydia. Certain male dragonflies, the ones that avoid territorial battles with other males, have blood-sugar concentrations similar to Type 2 diabetes. (Researchers have found that, while they look lean on the outside, they are actually storing excess fat on the inside.)
In fact, some of the book's more interesting findings explore the very diseases and psychological disorders that society has tended to consider uniquely human. In addition to the self-starving sows, for instance, wild animals binge-eat – an evolutionary behaviour in which the fittest consume more in times of plenty, the better to survive when food is scarce. As long as food keeps coming, they keep eating. "In the wild and in our homes, easy access to abundance leads to obesity," says Dr. Natterson-Horowitz, whose book also points out the impact that human preoccupations such as stress and sleep may have on animal weight gain.
The same theory is proposed for self-injury; which has been documented in "over-grooming" cats, which lick themselves bald in spots, and "flank-biting" horses, which nip their own bodies until they bleed. In humans, the behaviour is called "cutting," most commonly seen among teenage girls, and is hard to treat. Veterinarians naturally focus on the environment for treatment; they will move horses back into the herd for a while, or switch up their routine some other way, in the hope of reducing stress and boredom. Zoobiquity, by focusing on the similarities between humans and animals, points medicine in a relatively unplumbed direction: Can what works for horses, for example, teach psychiatrists how to better treat some of the more baffling mental-health problems in human beings?
"We are really just at the beginning of thinking about things this way," Dr. Natterson-Horowitz says. Collaborations are growing, in particular between human and animal oncologists.
But the concept of zoobiquity makes a point beyond medical practice, Dr. Natterson-Horowitz suggests. For one thing, once society accepts that animals also suffer problems such as addiction, depression and obesity (and that the treatments may be shared between species), it's hard to argue that these are uniquely human "failings," with the shame and blame that this entails.
Considering the stoner wallabies in the poppy fields, Dr. Natterson-Horowitz said, "You couldn't say that one wallaby is weaker or more morally strong than the other."
But, ultimately, zoobiquity reinforces the interconnectedness of life on Earth. As animals get healthy, so do we. "Human beings are not the only patients on the planet," Dr. Natterson-Horowitz says.
In another words, we're all in this together.