What can be learned about eating disorders, anxiety and STDs -- from animals? The authors of a new book share the surprising parallels between humans and other species. Kathryn Bowers and Dr. Barbara Natterson-Horowitz join us on Chicago Tonight at 7:00 pm. Read an excerpt from Zoobiquity, view a photo gallery and watch videos about animal behavior.
Dr. House, Meet Doctor Dolittle
Redefining the Boundaries of Medicine
“Uh, listen, Barbara? We’ve got an emperor tamarin in heart failure. Any chance you could come out today?”
I reached for my car keys. For thirteen years I’d been a cardiologist treating members of my own species at the UCLA Medical Center. From time to time, however, the zoo veterinarians asked me to weigh in on some of their more difficult animal cases. Because UCLA is a leading heart-transplant hospital, I’d had a front-row view of every type of human heart failure. But heart failure in a tamarin—a tiny, nonhuman primate? That I’d never seen. I threw my bag in the car and headed for the lush, 113-acre zoo nestled along the eastern edge of Griffith Park.
Into the tiled exam room the veterinary assistant carried a small bundle wrapped in a pink blanket.
“This is Spitzbuben,” she said, lowering the animal gently into a Plexiglas-fronted examination box. My own heart did a little flip. Emperor tamarins are, in a word, adorable. About the size of kittens, these monkeys evolved in the treetops of the Central and South American rain forests. Their wispy, white Fu Manchu–style mustaches droop below enormous brown eyes. Swaddled in the pink blanket, staring up at me with that liquid gaze, Spitzbuben was pushing every maternal button I had.
When I’m with a human patient who seems anxious, especially a child, I crouch close and open my eyes wide. Over the years I’ve seen how this can establish a trust bond and put a nervous patient at ease. I did this with Spitzbuben. I wanted this defenseless little animal to understand how much I felt her vulnerability, how hard I would work to help her. I moved my face up to the box and stared deep in her eyes—animal to animal. It was working. She sat very still, her eyes locked on mine through the scratched plastic. I pursed my lips and cooed.
“Sooo brave, little Spitzbuben...”
Suddenly I felt a strong hand on my shoulder.
“Please stop making eye contact with her.” I turned. The veterinarian smiled stiffly at me. “You’ll give her capture myopathy.”
A little surprised, I did as instructed and got out of the way. Animal-human bonding would have to wait, apparently. But I was puzzled. Capture myopathy? I’d been practicing medicine for almost twenty years and had never heard of that diagnosis. Myopathy, sure—that simply means a disease that affects a muscle. In my specialty, I see it most often as “cardiomyopathy,” a degradation of the heart muscle. But what did that have to do with capture?
Just then, Spitzbuben’s anesthesia took effect. “Time to intubate,” the attending veterinarian instructed, focusing every person in the room on this critical and sometimes difficult procedure. I pushed capture myopathy out of my mind to be fully attentive to our animal patient.
But as soon as we were finished and Spitzbuben was safely back in her enclosure with the other tamarins, I looked up “capture myopathy.” And there it was—in veterinary textbooks and journals going back decades. There was even an article about it in Nature, from 1974. Animals caught by predators may experience a catastrophic surge of adrenaline in their bloodstreams, which can “poison” their muscles. In the case of the heart, the overflow of stress hormones can injure the pumping chambers, making them weak and inefficient. It can kill, especially in the case of cautious and high-strung prey animals like deer, rodents, birds, and small primates. And there was more: locking eyes can contribute to capture myopathy. To Spitzbuben, my compassionate gaze wasn’t communicating, “You’re so cute; don’t be afraid; I’m here to help you.” It said: “I’m starving; you look delicious; I’m going to eat you.”
Though this was my first encounter with the diagnosis, parts of it were startlingly familiar. Cardiology in the early 2000s was abuzz with a newly described syndrome called takotsubo cardiomyopathy. This distinctive condition presents with severe, crushing chest pain and a markedly abnormal EKG, much like a classic heart attack. We rush these patients to an operating suite for an angiogram, expecting to find a dangerous blood clot. But in takotsubo cases, the treating cardiologist finds perfectly healthy, “clean” coronary arteries. No clot. No blockage. No heart attack.
On closer inspection, doctors notice a strange, lightbulb-shaped bulge in the left ventricle. As the pumping engines for the circulatory system, ventricles must have a particular ovoid, lemonlike shape for strong, swift ejection of blood. If the end of the left ventricle balloons out, as it does in takotsubo hearts, the firm, healthy contractions are reduced to inefficient spasms—floppy and unpredictable.
But what’s remarkable about takotsubo is what causes the bulge. Seeing a loved one die can do it. So can being left at the altar or losing your life savings with a bad roll of the dice. Intense, painful emotions in the brain can set off alarming, life-threatening physical changes in the heart. This new diagnosis was indisputable proof of the powerful connection between heart and mind. Takotsubo cardiomyopathy was tangible evidence of a relationship many doctors had considered more metaphoric than diagnostic.
As a clinical cardiologist, I needed to know how to recognize and treat takotsubo cardiomyopathy. But years before pursuing cardiology, I had completed a residency in psychiatry at the UCLA Neuropsychiatric Institute. Having also trained as a psychiatrist, I was captivated by this syndrome, which lay at the intersection of my two professional passions.
That background put me in a unique position that day at the zoo. I reflexively placed the human phenomenon side by side with the animal one. Emotional trigger...surge of stress hormones...failing heart muscle...possible death. An unexpected “aha!” suddenly hit me. Takotsubo in humans and the heart effects of capture myopathy in animals were almost certainly related—perhaps even the same syndrome with different names.
But a second, even stronger insight quickly followed this “aha.” The key point wasn’t the overlap of the two conditions. It was the gulf between them. For nearly four decades (and probably longer) veterinarians had known this could happen to animals—that extreme fear could damage muscles in general and heart muscles in particular. In fact, even the most basic veterinary training includes specific protocols for making sure animals being netted and examined don’t die in the process. Yet here were the human doctors in early 2000 trumpeting the finding, savoring the fancy foreign name, and making academic careers out of a “discovery” that every vet student learned in the first year of school. These animal doctors knew something we human doctors had no clue existed. And if that was true...what else did the vets know that we didn’t? What other “human” diseases were found in animals?
So I designed a challenge for myself. As an attending physician at UCLA I see a wide variety of maladies. By day on my rounds, I began making careful notes of the conditions I came across. At night, I combed veterinary databases and journals for their correlates, asking myself a simple question: “Do Animals Get [fill in the disease]?”
I started with the big killers. Do animals get breast cancer? Stress-induced heart attacks? Leukemia?
How about melanoma? Fainting spells? Chlamydia?
And night after night, condition after condition, the answer kept coming back “yes.” The similarities clicked into place.
Jaguars get breast cancer and may carry the BRCA1 genetic mutation that predisposes many Jews of Ashkenazi descent and others to the disease. Rhinos in zoos get leukemia. Melanoma has been diagnosed in the bodies of animals from penguins to buffaloes. Western lowland gorillas die from a terrifying condition in which the body’s biggest and most critical artery, the aorta, ruptures. Torn aortas also killed Lucille Ball, Albert Einstein, and the actor John Ritter, and strike thousands of less famous human beings every year.
I learned that koalas in Australia are in the middle of a rampant epidemic of chlamydia. Yes, that kind—sexually transmitted. Veterinarians there are racing to produce a koala chlamydia vaccine. That gave me an idea: doctors around the United States are seeing human chlamydia infection rates spike. Could the koala research inform human public health strategies? Since unprotected sex is the only kind koalas have (my searches for condom use by animals came up short), what might those koala experts know about the spread of sexually transmitted diseases in a population that practices nothing but “unsafe” sex?
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 wild- life biologists, in the field, the lab, and the clinic? Maybe such collabora- tions 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 doc- tor, 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 rev- enue 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 accompa- nying 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 phy- sician, 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 ani- mals 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 got- ten 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 vac- cination. 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, scien- tific 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 cheer- ful 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 ani- mals. 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 intro- duces 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.
Excerpted from Zoobiquity by Barbara Natterson-Horowitz, M.D., and Kathryn Bowers. Copyright 2012 by Barbara Natterson-Horowitz. Excerpted by permission of Knopf, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Do Animals Get High? Watch the following video:
Do Animals Get Breast Cancer? Watch the following video:
Do Animals Get Eating Disorders? Watch the following video:
All photos are courtesy of Zoobiquity authors, Kathryn Bowers and Dr. Barbara Natterson-Horowitz.