Zoobiquity (2 page)

I wondered about obesity and diabetes—two of the most pressing health concerns of our time. I burned midnight pixels investigating questions like: Do wild animals get medically obese? Do animals overeat or binge-eat? Do they hoard food and eat in secret at night? I learned that yes, they do. Comparing animal grazers, gorgers, and regurgitators
to human snackers, diners, and dieters transformed my views on conventional human nutritional advice—and on the obesity epidemic itself.

Very quickly, I found myself in a world of surprising and unfamiliar new ideas, the kinds I’d never been encouraged to entertain in all my years of medical training and practice. It was, frankly, humbling, and I started to see my role as a physician in a whole new way. I wondered: Shouldn’t human and veterinary doctors be partnering, along with wildlife biologists, in the field, the lab, and the clinic? Maybe such collaborations would inspire a version of my takotsubo moment, but for breast cancer, obesity, infectious disease, or other health concerns. Perhaps they would even lead to cures.

The more I learned, the more a tantalizing question started creeping into my thoughts: Why
don’t
we human doctors routinely cooperate with animal experts?

And as I searched for that answer, I learned something surprising. We used to.
In fact, a century or two ago, in many communities, animals and humans were cared for by the same practitioner—the town doctor, as he set broken bones and delivered babies, was not deterred by the species barrier. A leading physician of that era named Rudolf Virchow, still renowned today as the father of modern pathology, put it this way: “
Between animal and human medicine there is no dividing line—nor should there be. The object is different but the experience obtained constitutes the basis of all medicine.”
^*

However, animal and human medicine began a decisive split around the turn of the twentieth century. Increasing urbanization meant fewer people relied on animals to make a living. Motorized vehicles began pushing work animals out of daily life. With them went a primary revenue stream for many veterinarians. And in the United States, federal legislation called the
Morrill Land-Grant Acts of the late 1800s relegated veterinary schools to rural communities while academic medical centers rapidly rose to prominence in wealthier cities.

As the golden age of modern medicine dawned, there was simply more money, prestige, and academic reward to be had in pursuing human patients. For physicians, this era all but erased their tarnished image as the leech purveyors and potion makers of times past. But veterinarians enjoyed little to none of this skyrocketing social status and its accompanying wealth. The two fields moved through the twentieth century for the most part on divided, yet parallel, paths.

Until 2007.
That’s when a veterinarian named Roger Mahr and a physician, Ron Davis, arranged a meeting in East Lansing, Michigan. They compared notes on similar problems they encountered in their animal and human patients: cancer, diabetes, the adverse effects of secondhand smoke, and the explosion of “zoonoses” (diseases that spread from animals to humans, like West Nile virus and avian flu). They called for physicians and veterinarians to stop segregating themselves based on the species of their patients and start learning from one another.

Because Davis was president of the American Medical Association (AMA) and Mahr headed the American Veterinary Medical Association (AVMA), their meeting carried more weight than the handful of previous attempts to reunify the fields.
^†

But the Davis-Mahr announcement received little notice in the popular media, or even among medical professionals, especially physicians. True, One Health (the favored term for this movement) has gotten notice from the World Health Organization, the United Nations, and the Centers for Disease Control and Prevention
^‡
The Institute of Medicine, which is the health arm of the National Academy of Sciences, hosted a
One Health summit in Washington, D.C., in 2009. And veterinary schools, including those at the University of Pennsylvania, Cornell, Tufts, UC Davis, Colorado State, and the University of Florida, have embarked on One Health collaborations in education, research, and clinical care.

Yet, the truth is that most physicians will go through their entire careers never interacting with veterinarians, at least not professionally.
Until I started consulting at the zoo, the only time I even thought about animal doctors was when I brought my own dogs in for an exam or vaccination. My veterinary colleagues tell me they regularly read human medical journals to keep up on the latest research and techniques. But most physicians I know—including myself, until recently—would never dream of consulting an animal-focused monthly, even one as highly respected as the
Journal of Veterinary Internal Medicine
.

I think I know why. Most physicians see animals and their illnesses as somehow “different.” We humans have our diseases. Animals have theirs. And I suspect there’s another reason. The human medical establishment has an undeniable, though unspoken, bias against veterinary medicine. While most physicians have many laudable attributes—tireless work ethics, the desire to help others, a sense of duty to the community, scientific rigor—we have some dirty laundry I must reluctantly air. Doctors, it may or may not surprise you to learn, can be snobs. Ask your (non-M.D.) podiatrist, optometrist, or orthodontist if he’s ever felt condescension from someone with those two hallowed initials after her name, and you’ll likely hear some juicy tidbits about physician arrogance or that special brand of M.D. noblesse oblige.

By the way, we do it even to each other. You won’t find a group of cocky neurosurgical residents sharing coffee and muffins with the cheerful family practice team or the empathetic psych interns. There is an unwritten hierarchy. The more competitive, lucrative, procedure-driven, and “elite” specialties sit at the top of the physician self-importance pyramid. Given how readily physicians rank themselves based on which body part they minister to, just imagine the disdain they might work up for mere “animal docs.” I’m sure it would shock some of my colleagues to learn that vet school is now harder to get into than med school.

When some vets tell me about this historical antipathy between our fields, many bristle about not being taken seriously as “real” doctors. But while it rankles when M.D.’s condescend, most vets simply take a resigned approach to their glitzier counterparts on the human side. Several have even confided to me a veterinarians’ inside joke:
What do you call a physician? A veterinarian who can treat only one species
.

Still, among physicians, welcoming animal doctors as peers just “isn’t done.” As Darwin shrewdly observed, “
we do not like to consider [animals] our equals.” And yet, all of biology, the foundation of medicine
itself, relies on the fact that we
are
animals. Indeed, we share the vast majority of our genetic code with other creatures.

And, of course, on some level we accept this vast biological overlap: almost every medicine we take—and prescribe—has been tested on animals. Indeed, if you asked most physicians what animals can teach us about human health, there is one place they would automatically point: the lab. But that is precisely not what I am talking about.

This book isn’t about animal testing. Nor is it about the complex and important ethical issues of lab animal investigation. Instead, it introduces a new approach that could improve the health of both human
and
animal patients. This approach is based on a simple reality: animals in jungles, oceans, forests, and our homes sometimes get sick—just as we do. Veterinarians see and treat these illnesses among a wide variety of species. And yet physicians largely ignore this. That’s a major blind spot, because we could improve the health of all species by learning how animals live, die, get sick, and heal in their
natural
settings.

As I started to focus on sameness, instead of being distracted by difference, it changed how I viewed my patients, their diseases, and even what it means to be a doctor. The line between “human” and “animal” started to blur. It was unsettling at first. Every echocardiogram I performed—on humans at UCLA and animals at the L.A. Zoo—suddenly exploded with familiarity and new meaning. Every mitral valve, every left ventricular apex, carried the echoes of our shared evolution and health challenges.

The cardiologist in me was thrilled with this new perspective, the myriad overlaps. But as a psychiatrist, I wasn’t so sure. Physical similarities were one thing. Blood, bones, and beating hearts animate not just primates and other mammals but also birds, reptiles, and even fish. Still, I assumed, our uniquely developed human brains meant the similarities ended with our bodies. Certainly the overlap couldn’t extend to our minds and emotions. So I came at the question from a psychiatric perspective.

Do animals get … obsessive-compulsive disorder (OCD)? Clinical depression? Substance addiction and abuse? Anxiety disorders? Do animals ever take their own lives? And again I sat back, a little astounded, while my research yielded a series of fascinating and surprising answers.

Octopuses and stallions sometimes self-mutilate, in ways that echo the
self-injuring patients we call “cutters.”
Chimpanzees in the wild experience depression and sometimes die of it.
The compulsions psychiatrists treat in their patients with OCD resemble behaviors veterinarians see in animal patients and call “stereotypies.”

Suddenly, the benefits for human
mental
health seemed enormous. Perhaps a human patient compulsively burning himself with cigarettes could improve if his therapist talked shop with a bird specialist who had treated dozens of parrots with feather-picking disorder.
Maybe Princess Diana or Angelina Jolie (who both publicly admitted cutting themselves with blades) could have found solace in discussing their urges with an equestrian expert who treats horses that compulsively bite themselves.

Significantly for addicts and their therapists, species from birds to elephants are known to seek out psychotropic berries and plants for the presumed purpose of changing their sensory states—a.k.a. getting high. Bighorn sheep, water buffaloes, jaguars, and primates of many kinds consume—and then show the effects of—narcotics, hallucinogens, and other intoxicants. Naturalists have been noting these behaviors in the field for decades. Is a treatment—or at least a new perspective—for alcoholism or addiction lying dormant in all that animal research?

I also searched for veterinary examples of depression and suicide. It seemed unlikely that animals would experience the same psychiatric urges to kill themselves that humans do. While the similar nature of their emotions has been persuasively described by behaviorists and veterinarians, I doubted that other animals share our foresight of death or knowledge of its power. Still I asked, “Do animals commit suicide?”

Well, they don’t tie nooses around their necks or shoot themselves with revolvers, and they don’t leave notes explaining why they did it.
But examples of what appears to be grief-related and life-threatening “self-neglect” (refusing food and water) crop up throughout the scientific literature and in accounts that veterinarians and pet owners tell. And insect suicide, driven by parasitic infection, has been well documented by entomologists.

Which raises an interesting issue. Our physical body structures evolved over hundreds of millions of years. Perhaps modern human emotions too have evolved over millennia. Has natural selection played a role in what we feel, from anxiety, grief, and shame to pride, joy, and even schadenfreude?

Although Darwin himself studied and wrote extensively about natural
selection’s influence on human and animal emotions, none of my psychiatric training even touched on the possibility that human feelings could have evolutionary roots. In fact, it was almost the opposite. My education included stern warnings against the tantalizing pull to anthropomorphize. In those days, noticing pain or sadness on the face of an animal was criticized as projection, fantasy, or sloppy sentimentality. But scientific advancements of the past two decades suggest that we should adopt an updated perspective. Seeing too much of ourselves in other animals might not be the problem we think it is. Underappreciating our own animal natures may be the greater limitation.

As a psychiatrist, I was officially convinced. Remaining ignorant of the mental and physical disorders of animals, I began to feel, was as narrow-minded as refusing to seek out important human research simply because it was reported in a foreign language.

Still, the skeptic in me looked for any reason to explain away the similarities. Perhaps it was simply our shared environment. And after all, we humans have commandeered the food chain, imposing our dominant diets, weapons, and diseases on everything below us.

So I began to look anew at conditions I’d long assumed to be uniquely human and modern. And with that I came across some remarkable findings: dinosaurs with gout, arthritis, stress fractures … even cancer.
Not so long ago, paleontologists uncovered a mass in the fossilized skull of a
Gorgosaurus
, a close relative of
Tyrannosaurus rex
. A brain tumor, they said, had brought down one of the Earth’s most notorious carnivores, connecting a late-Mesozoic cancer patient to human brain cancer victims, including the composer George Gershwin, reggae artist Bob Marley, and U.S. Senator Ted Kennedy.

Having spent a career taking care of human patients in the here and now, I was suddenly confronted by a shifted boundary. Cancer has struck and killed its victims for at least seventy million years. I wondered how this knowledge might redefine how patients and physicians view the disease … or even how oncologists might search for ways to cure it.

Around this time I started working with Kathryn Bowers, a science journalist. A nondoctor with a background in social science and literature, she saw wider implications in these medical similarities. She urged me to view my overlapping experiences at the zoo and the hospital in a broader
context. Together we began to research and write this book, bringing together medicine, evolution, anthropology, and zoology.