Who gets more respect: doctors or veterinarians? Veterinarians like to joke that physicians are vets who only know how to take care of one species. But that joke is only funny because of the usual pecking order: Doctors who treat humans are seen, and see themselves, as occupying the more knowledgeable and skilled position.
Barbara Natterson-Horowitz, a cardiologist at the University of California Los Angeles, wants to turn that assumption on its head. She believes that her fellow human physicians have much to learn from their veterinary counterparts—and that we shouldn’t see human and animal medicine as separate fields. During a stint moonlighting as a cardiologist for animals at the Los Angeles Zoo, she became fascinated with the similarities between veterinary diseases and human ones. Now she’s on a mission to raise the status of animal medicine and convince doctors to cross the species divide.
In a new book coauthored with science writer Kathryn Bowers, “Zoobiquity: What Animals Can Teach Us About Health and the Science of Healing,” Natterson-Horowitz details surprising similarities between human and animal disease. Animals get cancer, heart disease, and influenza, but they also get medical problems we think of as purely human. Fish faint, marmots get obese, stallions struggle with sexual performance problems, koalas get chlamydia, and animals of all kinds self-injure when faced with stress, isolation, and boredom.
While we acknowledge our close genetic similarity to other animals, the authors say, we’ve ignored the striking physical and psychological parallels between humans and other species. Veterinarians have insight that could help physicians find new treatments—but right now, most physicians would never think to read a veterinary journal or attend an animal medicine meeting.
As Natterson-Horowitz acknowledges, such collaboration will require a dramatic cultural change. But that conversation is beginning; she led a “zoobiquity” conference last year, where human and animal doctors discussed shared medical problems on the same stage, and another is planned for September. She talked with Ideas by phone about why physicians and patients should embrace their animal nature.
IDEAS: Why should doctors listen to veterinarians?
NATTERSON-HOROWITZ: I can speak from my own personal experience. I had spent almost a couple decades being a human doctor, a cardiologist, and I had very little awareness about veterinary medicine. I, like most physicians, only interacted with veterinarians when my own animals got sick....I had this wonderful opportunity to help out at the Los Angeles Zoo, and through that experience I began seeing, both through the patients I was helping with and listening to the veterinarians on their rounds, that they were dealing with heart failure, and cancer, and behavioral disturbances, and infectious diseases, and really essentially the same diseases that I was taking care of in human patients.
IDEAS: And you saw this in your own field?
NATTERSON-HOROWITZ: The book starts with an interesting tamarin who had heart failure. That was when I had my kind of “aha” moment. The vet told me about this syndrome I’d never heard of before in animals called “capture myopathy.” And it sounded a lot like a recently classified human cardiovascular disorder, basically a stress induced heart failure [takotsubo cardiomyopathy]....And the more I learned, the more I realized...this is probably very much the same clinical syndrome. That was interesting, but what was unbelievable was when I found out capture myopathy had been in the veterinary literature for decades, and takotsubo cardiomyopathy had made a splashy entrance in about 2000.
IDEAS: Medical science relies a lot on studying lab animals. How is this different?
NATTERSON-HOROWITZ: If you ask most doctors what animals can teach us about health, they’ll point to the laboratory. Zoobiquity is really a different approach. It’s supposed to look at how animals move and die and get sick naturally.
IDEAS: You say that even diseases that we think of as uniquely human—depression, sexual problems, addiction—can be found in animals. Did that surprise you?
NATTERSON-HOROWITZ: When I first saw the overlap at the zoo, I thought, well, it can’t be that extensive. I was 100 percent positive that there were diseases that were unique to humans. So I created a kind of game for myself where if I saw something in a human patient, I’d look for it in the veterinary literature. The first questions I had were: Do they get breast cancer, Hodgkin’s lymphoma, melanoma, brain tumors, erectile dysfunction, syphilis? And of course the answer to all of that was yes, and those were surprising to me. But then when I applied the same methodology to behavioral disturbances—do animals get obsessive compulsive disorder, do they get separation anxiety, eating disorders, suicidal behavior? Do they self-injure, and even do they get high? The answer to all of those questions also was “yes.”
IDEAS: How far we should take this idea? Should people and animals be treated together?
NATTERSON-HOROWITZ: I don’t think we’re at a place where we could have animals and humans share emergency rooms [laughs].
IDEAS: Veterinarians usually deal with animals in captivity and pets—what about wild animals?
NATTERSON-HOROWITZ: The reality is it’s very hard to know what’s happening in the wild medically. We can assume that these animals are not developing some of the diseases we give ourselves. But there are a lot of diseases we have no idea about....There’s fossil evidence in dinosaurs of stress fractures and gout. When I think gout, I think Henry the Eighth.
IDEAS: So is there anything from a medical perspective that makes humans unique?
NATTERSON-HOROWITZ: There are certain diseases that because of our habits, our lifestyle, our environment, we have amplified. The great cardiac killer is what we call epicardial coronary artery disease, which is a blockage of the artery to the heart that causes heart attacks. That is not a disease that’s seen in most animals spontaneously. So yes, of course, there are some things that are unique...but that is, I think, a tiny fraction of the vast overlap.
IDEAS: Your thesis carries an implicit critique against physicians. Why have they ignored veterinary medicine, and what needs to happen for the culture to change?
NATTERSON-HOROWITZ: It’s a fair statement to say that physicians typically have not considered vets their clinical peers. There are a number of reasons for that—some have to do with the history of the professions, which have had somewhat separate paths for about 100 years. Some of it has to do, frankly, with our inconsistent and ambivalent perspective on how much we are actually animals....
The field of comparative medicine has existed for hundreds of years...[and] has been very important in the lab and among pathologists. But the perspective I’m trying to bring into this is that there’s a role for comparative medicine at the human bedside....I think the culture will change as we’re able to demonstrate that we can create new knowledge, and I feel certain we can.