While consulting at the Los Angeles Zoo, a light bulb went off for UCLA cardiologist Barbara Natterson-Horowitz, M.D. "The diseases of the animal patients I saw at the zoo often were essentially the same as those we see in humans," she says. "I had an 'ah-hah' moment: What might physicians learn if we looked at human medical concerns through the lens of veterinary medicine?" Thus began her six-year journey, systematically examining a variety of human conditions - from heart disease to sexual dysfunction and addiction - to find overlaps in the animal world. The result of that exploration is Zoobiquity: What Animals Can Teach Us About Health and the Science of Healing (Knopf, 2012), co-authored with science journalist Kathryn Bowers. Dr. Natterson-Horowitz spoke with U Magazine editor David Greenwald about Zoobiquity and her conclusions.
Photos by Ann Johansson
The word "zoobiquity" has not yet made its way into the Oxford English Dictionary. What does it mean?
Dr. Natterson-Horowitz: In writing this book, Kathryn and I wanted to create a novel approach to important human medical concerns that brought the perspectives of veterinary science, evolutionary biology and even ecology to the human bedside. We needed a term to describe it, so we coined the word "zoobiquity," which brings together zoo, which is Greek for animal, and ubiquity, Latin for everywhere. It is meant to describe this fusion of ideas trained on important human medical concerns.
What got you started on this exploration?
Dr. Natterson-Horowitz: My first epiphany was the realization that whether we treat humans or horses or dogs and cats, all doctors are really veterinarians. We physicians might actually consider ourselves veterinarians with a single-species focus. But the bigger spark came from spending time on rounds with veterinarians, watching their procedures, listening to their clinical decision making. Much was very familiar; other aspects were unique. I wondered, what approaches and perspectives veterinarians had that might be useful to human medicine. I was intrigued by the possibility that translational insights might be hiding in plain sight. We began asking questions such as, do animals get breast cancer? Yes, they do. Do they get heart failure? Yes. Do they get STDs? Yes. Do they suffer from mental illness? Yes. To almost every question we asked, the answer was a resounding "yes." Veterinarians learn comparatively from the beginning of veterinary school and are therefore very aware of this. Most physicians, on the other hand, are unfamiliar with the tremendous overlap among the diseases of their human patients and animals in our homes, our farms and in the wild.
The human-animal overlaps you describe in the book are fascinating - drug-seeking wallabies in Tasmania, obese dragonflies, depressed gorillas - and often quite surprising. How does it then relate to human medicine?
Dr. Natterson-Horowitz: Let's consider issues of mental illness, specifically self-injury. Before I trained as a cardiologist, I completed a residency in psychiatry. I assumed that self-injury was uniquely human, triggered by contemporary psychopathology. My assumption was wrong. Self-injury is seen in a broad spectrum of animals. Parrots and other birds pluck out their feathers in a disorder that is reminiscent of trichotillomania, a human disorder characterized by the plucking out of facial and other hairs. Some birds will peck at their skin until it bleeds, suggesting parallels with human cutting. There are dogs that obsessively lick until the fur comes off and sometimes the skin breaks and bleeds, and horses will bite their flanks.
That is interesting, but how is it relevant? Consider that if a human patient presents with self-injury, the traditional approach has been to explore life history, childhood and transitional experiences, to engage the patient in better self-understanding. This approach can be helpful. But a veterinarian doesn't have access to language; he or she can't ask the parrot or the horse about childhood traumas that might be contributing to their behavior. But veterinarians recognize three conditions known to elicit self-injury in animals: stress, isolation and boredom. So when a horse starts to bite its flank, a veterinarian will intervene by targeting these factors. They combat isolation by putting the horse together with other horses - returning this herd animal to its herd - or even by placing a small animal such as a chicken in its stall. They alleviate stress or boredom by striving to increase the animal's activity. Instead of just strapping on a food bag to feed a horse, they spread out their food and make them forage, so it becomes a greater challenge. These strategies are remarkably successful in attenuating these behaviors in animals. I think psychotherapists could consider treatments targeting isolation, boredom and stress triggers in their human patients in addition to the insight-oriented work they do with self-injurers. Perhaps a human patient compulsively burning himself with cigarettes could improve if his therapist consulted a bird specialist experienced in the treatment of parrots with feather-picking disorder or an equine behaviorist who has managed flank-biting stallions.
We also understand that some self-injury in animals may represent an amplification of normal self-soothing grooming behavior. Over-licking syndromes in dogs may share neurobiology with humans with forms of obsessive-compulsive disorder involving excessive washing and grooming. Patients and their doctors could benefit from the recognition that across the animal kingdom, the urge to groom can be dialed up significantly, becoming pathological and dangerous. Knowing that these disorders are not uniquely human may help some patients to better deal with the stigma and shame that too often accompany mental illnesses.
Another issue you discuss at great length is addiction.
Dr. Natterson-Horowitz: We asked the question, "Do animals get high?" Although we were very skeptical, we quickly learned that many animals appear to seek out substances and become intoxicated. Cedar waxwing birds are notorious for eating fermented berries and flying while intoxicated and smashing into windows. Wallabies in Tasmania invade fields where medical opium is grown to eat the poppies, and some of them become quite intoxicated, sustaining injuries or even die as a consequence. There are reindeer who seek out hallucinogenic mushrooms, and bighorn sheep in the Canadian Rockies have been known to scale very steep cliffs to get to a type of psychoactive lichen. They seem to like it so much and want it so much that they will grind their teeth down to the gums trying to scrape it off the rocks. It is incredibly difficult for an addict to "just say no." Saying no, it turns out, is also hard for some animals.
Again, why is this relevant? Simply learning that the neurobiology underlying addiction is species-spanning and ancient has the potential to help patients understand their struggle with less guilt and self-recrimination. Greater awareness of the comparative aspects of substance use could also aid in the destigmatization of substance abuse and addiction.
Obesity is another key area you discuss. How does what is known about obesity in animals relate to obesity in humans?
Dr. Natterson-Horowitz: There's an epidemic of obesity among human beings, and it turns out there are parallel epidemics of obesity occurring in other species, starting with domestic animals. Our cats and dogs are getting heavier, and in some cases dangerously so. There also are some wild populations of animals that are getting fatter. We learned that across the animal kingdom, when animals have access to abundance, they over-consume. They binge eat. They hoard food. They are storing up for those periods when there is scarcity. Of course, in the wild the environment is very dynamic, and so while there may be periods of abundance, there are also typically periods of great scarcity. Animal experts understand obesity less as a function of the individual and more of the environment. Alter the animal's environment to decrease its access to food, to make it more difficult to get food, and the animal will slim down.
It was also very interesting to hear some of the veterinarians we spoke with talk about some other environmental factors that contribute to weight gain. For example, the microbiome - the trillions of organisms that grow in our and animals' bodies that can affect everything from our metabolism to our immune systems - is believed to affect weight gain in the animal kingdom.
How is that applicable to human populations?
Dr. Natterson-Horowitz: Applying a zoobiquitous approach to an obese human patient would involve looking at human obesity as primarily a disease of the environment. Physicians would first consider factors such as the built environment, the ease of access to and abundance of surrounding food, the microbiome, circadian rhythms, and even seasonal effects. This shift in perspective would be a translational insight from the world of veterinary medicine that could represent a shift in perspective that could lead to effective interventions aimed less at the individual and more at communities and governments with the power to influence the home environment.
What ultimately do you hope will be the outcome from Zoobiquity?
Dr. Natterson-Horowitz: Our connection with animals is ancient and deeply connected to human health. A species-spanning, interdisciplinary approach has the potential to yield benefits for the health not only of humans, but also animals. Taking language from the final page of our book, zoobiquity calls for physicians and patients to think beyond the human bedside to barnyards, jungles and skies. Because the fate of our world's health doesn't depend solely on how we humans fare. Rather, it will be determined by how all the patients on the planet live, grow, get sick, and heal.
For more information about Zoobiquity, go to: www.zoobiquity.com/book