gt;CONTENTSgt;gt;gt;Authors’ Note ix gt;gt;ONE gt;gt;Dr. House, Meet Doctor Dolittle 3gt;gt;Redefining the Boundaries of Medicinegt;gt;gt;TWO gt;gt;The Feint of Heart 19 gt;gt;Why We Pass Outgt;gt;gt;THREE gt;gt;Jews, Jaguars, and Jurassic Cancer 31 gt;gt;New Hope for an Ancient Diagnosisgt;gt;gt;FOUR gt;gt;Roar-gasm 55 gt;gt;An Animal Guide to Human Sexualitygt;gt;gt;FIVE gt;Zoophoria 87 gt;gt;Getting High and Getting Cleangt;gt;gt;SIX gt;Scared to Death 109 gt;gt;Heart Attacks in the Wildgt;gt;gt;SEVEN gt;Fat Planet 132 gt;gt;Why Animals Get Fat and How They Get Thingt;gt;gt;EIGHTgt;gt;Grooming Gone Wild 159 gt;gt;Pain, Pleasure, and the Origins of Self-Injurygt;gt;gt;NINEgt;Fear of Feeding 176 gt;gt;Eating Disorders in the Animal Kingdomgt;gt;gt;TENgt;The Koala and the Clap 194 gt;gt;The Hidden Power of Infectiongt;gt;gt;ELEVENgt;gt; Leaving the Nest 212 gt;gt;Animal Adolescence and the Risky Business of Growing Upgt;gt;gt;TWELVEgt;gt;Zoobiquity 234gt;gt;gt;Acknowledgments gt;245 gt;gt;Notes gt;249 gt;gt;Indexgt; 293gt;gt;gt;gt;gt;CHAPTER ONEgt;gt;gt;Dr. House, Meet Doctor Dolittlegt;gt;Redefining the Boundaries of Medicinegt;gt;gt;gt;In the spring of 2005, the chief veterinarian of the Los Angeles Zoo called me, an urgent edge to his voice.gt;gt;“Uh, listen, Barbara? We’ve got an emperor tamarin in heart failure. Any chance you could come out today?”gt;gt;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.gt;gt;Into the tiled exam room the veterinary assistant carried a small bundle wrapped in a pink blanket.gt;gt;“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.gt;gt;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 Igt; feltgt; 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.gt;gt;“Sooo brave, little Spitzbuben . . . ”gt;gt;Suddenly I felt a strong hand on my shoulder.gt;gt;“Please stop making eye contact with her.” I turned. The veterinarian smiled stiffly at me. “You’ll give her capture myopathy.”gt;gt;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?gt;gt;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.gt;gt;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 gt;Nature,gt; 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.”gt;gt;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.gt;gt;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.gt;gt;But what’s remarkable about takotsubo is what gt;causes gt;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.gt;gt;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.gt;gt;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. gt;Emotional trigger . . . surge of stress hormones . . . failing heart muscle . . . possible deathgt;. An unexpected “aha!” suddenly hit me. Takotsubo in humans and the heart effects of capture myopathy in animals were almost certainly related—gt;perhaps even the same syndrome with different names.gt;gt;gt;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?gt;gt;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 [gt;fill in the diseasegt;]?”gt;gt;I started with the big killers. Do animals get breast cancer? Stress-induced heart attacks? Leukemia?gt;gt;How about melanoma? Fainting spells? Chlamydia?gt;gt;And night after night, condition after condition, the answer kept coming back “yes.” The similarities clicked into place.gt;gt;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.gt;gt;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?gt;gt;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.gt;gt;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.gt;gt;gt;gt;The more I learned, the more a tantalizing question started creeping into my thoughts: Why gt;don’tgt; we human doctors routinely cooperate with animal experts?gt;gt;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.”gt;gt;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.gt;gt;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.gt;gt;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.gt;gt;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.gt;gt;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.gt;gt;Yet, the truth is that most physicians will go through their entire careers never interacting with veterinarians, at least not professionally.gt;gt;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 gt;Journal of Veterinary Internal Medicine.gt;gt;gt;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.gt;gt;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.gt;gt;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: gt;What do you call a physician? A veterinarian who can treat only one speciesgt;.gt;gt;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 gt;aregt; animals. Indeed, we share the vast majority of our genetic code with other creatures.gt;gt;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.gt;gt;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 gt;natural gt;settings.gt;gt;gt;gt;As I started to focus on sameness, instead of being distracted by differ- ence, 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.gt;gt;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 simi- larities 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.gt;gt;Do animals get . . . obsessive-compulsive disorder (OCD)? Clinical depression? Substance addiction and abuse? Anxiety disorders? Do ani- mals ever take their own lives? And again I sat back, a little astounded, while my research yielded a series of fascinating and surprising answers.gt;Octopuses and stallions sometimes self-mutilate, in ways that echo the self-injuring patients we call “cutters.” Chimpanzees in the wild experi- ence 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.”gt;gt;Suddenly, the benefits for human gt;mentalgt; 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.gt;gt;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 alco- holism or addiction lying dormant in all that animal research?gt;gt;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 vet- erinarians, I doubted that other animals share our foresight of death or knowledge of its power. Still I asked, “Do animals commit suicide?”gt;gt;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 scien- tific literature and in accounts that veterinarians and pet owners tell. And insect suicide, driven by parasitic infection, has been well docu- mented by entomologists.gt;gt;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?gt;gt;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 feel- ings 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 sentimental- ity. 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.gt;gt;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.gt;gt;Still, the skeptic in me looked for any reason to explain away the simi- larities. 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.gt;gt;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 find- ings: dinosaurs with gout, arthritis, stress fractures . . . even cancer. Not so long ago, paleontologists uncovered a mass in the fossilized skull of a gt;Gorgosaurusgt;, a close relative of gt;Tyrannosaurus rexgt;. 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 vic- tims, including the composer George Gershwin, reggae artist Bob Marley, and U.S. Senator Ted Kennedy.gt;gt;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.gt;gt;gt;gt;Around this time I started working with Kathryn Bowers, a science jour- nalist. 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.gt;gt;We started with a survey of how philosophers and scientists through the centuries have positioned our species among our fellow creatures. Clearly, for as long as humans have been able to ponder it, we’ve been of two minds about the apparent fact that we gt;aregt; animals. Judging by the written record going back at least as far as Plato, our ancestors acknowledged the obvious similarities between us and the so-called lesser creatures. Plato mused, “Man is the plumeless genus of bipeds; birds are the plumed.” At the same time, people have long wanted to preserve a definition of humanity that kept us on a higher plane.gt;gt;With gt;The Origin of Speciesgt;, Charles Darwin gave us a new (and, to many, unnerving) way to conceive of ourselves in relation to animals— positing that man and beast exist as different branches of the same tree rather than on different sides of a schism. Scholars of all stripes weighed in on whether and how humans were related to apes and other species.