Humans aren’t the only ones to suffer from eating disorders, heart disease, addictions and many other ailments. In Zoobiquity , cardiologist Barbara Natterson-Horowitz and journalist Kathryn Bowers examine the range of diseases and conditions that commonly afflict both people and other animals, including dogs.
Horowitz’s revelation that species-spanning commonalities exist was sparked when she was called to the LA Zoo to help a female Emperor tamarin (an adorable South American monkey) who was experiencing heart failure. She thought that making eye contact and cooing to her tiny patient was the best way to comfort her. Then a vet stepped in and warned her against doing that, telling her she might inadvertently kill the small primate by inducing “capture myopathy.”
Horowitz wasn’t familiar with the term, but quickly learned that this fatal condition can develop when an animal is caught by a predator and experiences a sudden surge of a stress hormone. Unfortunately, this reaction can also be triggered when an animal is held, stared and cooed at by a heart specialist! The eureka moment came when she recognized a connection between capture myopathy and a human cardiac condition, Takotsubo cardiomyopathy (broken-heart syndrome), which can be brought on by a variety of “intense, painful emotions … [that] set off life-threatening physical changes in the heart.” She was surprised to realize that a phenomenon veterinarians had known about for decades hadn’t been identified in humans until 2000. So she set out to see if other human diseases had counterparts in the animal kingdom. She began her inquiry by posing the simple question: “Do animals get [fill in the disease]?”
In each chapter, a human disease or disorder is described and then the animal counterpart is presented. They start by looking at fainting, something that one-third of adults have done at least once in their lives. By questioning vets, they found that dogs also experience “vasovagal syncope”—i.e., faint—in response to everyday activities “like barking and jumping … some canines faint when they’re aroused to sudden activity after being at rest.” And like us, some dogs faint when faced with a needle. In both cases, the reason has to do with a “fight or flight” response in which blood pressure rapidly decreases. In turn, the brain “shuts the system down by fainting.”
In the chapter “Grooming Gone Wild,” they look at human self-injurers (including Princess Diana and Colin Farrell) and compare them with dogs who obsessively lick and gnaw at their bodies in almost in trancelike state. It has been found that some compulsive behaviors in dogs, like this one, are genetically based. Whether OCD in humans and the canine equivalent (CCD) are the same disorder is something that has yet to be determined, but Horowitz puts forth a compelling case for a connection.
This book also gave me many insights, including why dogs thrive on reward-based training. It all has to do with neurocircuitry, which, we learn, is similar in most species, including our own. Basically, this system rewards fitness-promoting behaviors, such as foraging, hunting, “interacting with kin and peers,” mating, escape—behaviors that increase species survival. The authors characterize the rewards as a “chemical-dispensing apparatus stocked with tiny capsules of natural narcotics” such as opioids, cannabinoids, dopamine, oxytocin, and many others. As the authors note, accessing these chemicals is one of the most “potent motivators in animals, including us.” Even slugs have a dopaminergic system that controls the search and consumption of food. As animal expert Gary Wilson explains, “External treats in the form of food and congratulatory sounds are, in effect, bridges to the animal’s brain.” Simply put, good dog training is “driven by pleasure circuits.” Positive, reward-based learning is more effective than dominance- or coercive-based methods because it’s in tune with the way we and our dogs are wired.
This is a truly fascinating look at the similarities between us and other animals. We are not alone in our experience of a spectrum of physical and emotional disorders—among them, chlamydia, depression, bullying and risk-taking among adolescents. The list is long, and exploring it makes for engrossing and enlightening reading.