What 'Bad Dogs' Can Teach Humans About Compulsive Behavior

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Casey was diagnosed with canine compulsive disorder. He’s now on Prozac. (Courtesy)
Casey was diagnosed with canine compulsive disorder. He’s now on Prozac. (Courtesy)

When Casey, a 6-year-old German Shepherd, gets anxious, she chases her tail.

But it's not the kind of endearing, once-around-and-it's-done kind of tail-chasing we've all seen. Left unchecked, Casey circles around and around, pursuing her tail until she can bite it. Then, even when the blood starts flowing, the dog is driven to continue the chase.

"It's upsetting," says Paula Bagge, a Hopkinton, Mass. business owner who has been living with Casey since puppyhood. "And it's damaging. She hurls herself around the house, and it's like a big bloody paintbrush spraying the walls." Once, Bagge tied the dog's leash to a coffee table in an attempt to control the chasing. But Casey, who weighs about 85 pounds, just started dragging the coffee table around with her. Now, she's on Prozac.

In an earlier study, Dodman, a leading researcher on repetitive behavior in animals, found a specific gene associated with canine OCD.

Studying anxiety disorders in dogs, Dodman says, may ultimately help scientists come up with better therapies and medications to treat OCD and related conditions in people. Current drugs for OCD, such as SSRI's (or for dogs, a beef-flavored form of Prozac) are notoriously ineffective for many sufferers. Indeed, Dodman says, only around 43 to 60 percent of people suffering from OCD show a postive response from an SSRI; the average reduction of symptoms in people taking these drugs is only about 23 to 43 percent. "Certainly not a panacea," he says.

So, to further this research, Dodman spends time thinking about bears who pace obsessively, for instance, or parrots unable to stop preening and picking their feathers and beagles who overeat to the point of exploding,

Dodman calls the latest dog-brain imaging study, conducted in collaboration with researchers at McLean Hospital, in Belmont, Mass., "another piece of the puzzle, another brick in the wall."

He says while more research must be done, it's becoming increasingly evident that dogs with OCD are a great model for exploring human psychopathology: they show similar behaviors, respond to drugs in comparable ways and now, at least in this small study, seem to have the same brain abnormalities as people with the condition. "When you know what your dealing with it's much easier to create targeted approaches," to treatment, Dodman says. "If you don't know what you're dealing with it's just kind of like going with your sense of smell."

OCD afflicts about 2 percent of the population and often goes untreated or undiagnosed. People suffering from the disorder, marked by intrusive thoughts and repetitive behaviors such as hand washing, locking and unlocking doors, counting, or repeating the same steps, feel these impulses as uncontrollable. And the compulsive rituals, often triggered by stress or trauma, can be incredibly time-consuming, interfering with daily life.

Famously, Lena Dunham, the star and creator of the HBO series "Girls" came out with her own OCD on air, with repetitive tics, obsessive counting and painfully compulsive use of Q-tips.

Her disorder began at a relatively young age, according to a recent Rolling Stone interview:

Dunham was soon diagnosed with obsessive-compulsive disorder, which revved up around the age of nine. She went through a hypochondriacal phase: "AIDS, jaundice, you name it, I had it." Then she started counting. "I was obsessed with the number eight," she says. "I'd count eight times…. . . . I'd look on both sides of me eight times, I'd make sure nobody was following me down the street, I touched different parts of my bed before I went to sleep, I'd imagine a murder, and I'd imagine that same murder eight times."

Dogs with canine OCD also engage in repetitious and self-destructive behavior, notably, the tail-chasing and chewing, and in a sort of dog-version of obsessive hand-washing, non-stop licking of their paws, as well as flank sucking.

In fact, says Dodman, any behavior that is hard-wired for survivial — hunting, gathering, feeding, grooming — can become distorted in the extreme and expressed as a compulsive disorder: pacing, hoarding, overeating, hair-pulling. It's believed that a genetic predisposition coupled with an environmental trigger like stress, trauma or abuse can drive the pathology.

Consider these examples, offered by Dodman:

-- A parrot in a cage can't fly around and socialize; he's stuck all alone and becomes anxious. So he expresses this anxiety through overgrooming, a compulsion comparable to the human hair-pulling disorder, Trichotillomania. People with the condition will look for a certain hair with their fingers, pluck it out, inspect the bulb, then maybe chew, swallow or discard it. Parrots show similar behavior.

-- Beagles are known to have eating compulsions; some will eat until they explode, Dodman says.

-- A seal in an aquarium used to dive down to the botton and, in lieu of eating fish at the bottom of the sea, Dodman said, this seal would eat the pennies that tourists had tossed into the tank. The compulsive eating of inedible objects was not healthy, of course: every six months, Dodman said, caretakers would have to slit the seal's belly open and remove the pennies.

-- Tail-chasing can be an expression of predatory behavior, but instead of chasing a true predator, certain breeds chase themselves. "It's not cute," Dodman say.

-- Dobermans engage in flank and blanket sucking that can lead to bucked teeth and intestinal disturbances, for instance. It's an action derived from suckling, Dodman says, an appetitive behavior. "These disorders are not trivial," he says. "It's not good for human, animal companion bond."

Rob Petit's dog Lief, a 96-pound German Shepherd adopted from a shelter, chased leaves incessantly and never bonded or otherwise engaged with the people around him.

"He wouldn't interact, wouldn't make eye contact," says Petit, a software engineer in Attleboro, Mass. "He was in his own little world. You'd see him staring at a spot on the wall for noticeable amounts of time — 5-10 minutes — or he'd start chasing his tail. Dogs do that — it can be a cute, playful thing, but this was different. You could physically stop him, but then he'd go right back to it. This was a driven behavior."

Lief was diagnosed with canine OCD and, after an initial medication failed, he began taking Phenobarbitol, a powerful barbiturate, which completely transformed his behavior.

After Lief died of liver disease and a neurological condition, Petit got another German Shepherd who is also psychologically challenged. Chase, the dog, was recently diagnosed with extreme separation anxiety. How did Petit discover the condition? When he left the house, Chase chewed and clawed his way through a wooden door; he'd tear up the furniture and pee in the house. Now Chase takes Zoloft daily and the anti-anxiety drug Xanax, when needed. "It takes the edge off," Petit says.

It's becoming increasingly evident that when it comes to health and health care, animals  are very much like people. Hedgehogs are undergoing pricey cancer surgeries, horses get acupuncture for pain relief and cats and dogs are facing an obesity epidemic.

Dr. Barbara Natterson-Horowitz, a professor and cardiologist at the David Geffen School of Medicine at UCLA wrote a best-selling book called "Zoobiquity: The Astonishing Connection Between Human And Animal Health," which examines the importance of investigating animal health, including mental health, to better understand and treat human illnesses and conditions.

In a chapter called, "Grooming Gone Wild" about obsessive, cleaning-related behaviors, she writes:

Many of the compulsive behaviors seen in horses, reptiles, birds, dogs, and humans share core clinical features, including the potential to cause suffering and profoundly disrupt a patient's life.

Natterson-Horowitz, who is also a trained psychiatrist, wasn't involved in Dodman's research studies. But she says his work is profoundly important, in a field that's been "overlooked."

"There has been so much reluctance to allow ourselves to consider that animals have mental illness," she said. "Now we are beginning to acknowledge the overlap in compulsive and anxiety disorders — this whole field is emerging."

She says there's something truly clarifying about "understanding the suffering associated with human psychopathology through animals."

To that end, she says, she shows her medical students video of a dog with OCD chasing his tail. "You see this poor dog, chasing, chasing," she says. "In the beginning, the students are laughing, and I just let the video run.  As it continues, the laughing subsides and it gets very quiet because the students realize this 'patient' — animal — can't do anything but this unattainable task of running and running trying to catch his tail. Watching that dog suffering is so intense, it's really helpful for students and gives them a better understanding of how humans suffer from this."

Natterson-Horowitz also says that Dodman's work on the genetics of OCD will ultimately go a long way toward de-stigmatizing mental illness. "As we recognize that, just as diabetes, there's a genetic substrait that underlies this, and that mental illness has a biologic and genetic infrastructure, that will help the stigma to fall apart," she says.

As for Casey, the tail-chasing dog, her owner, Paula Bagge, is simply resigned to dealing with her unique behavior. "The doctor said to me, 'You just have to face it, you have a special needs dog," Bagge said. "We wouldn't give her away, who would take care of her? You wouldn't get rid of your own kid."

For more background, here's extra detail on Dodman's study, which was published online in Progress in Neuro-Psychopharmacology & Biological Psychiatry, from the Tufts news release:

The Tufts/McLean research team, led by Niwako Ogata, BVSc, Ph.D., who was a behavior researcher at the Cummings School of Veterinary Medicine and is now an assistant professor of animal behavior at Purdue University College of Veterinary Medicine, examined a sample of 16 Dobermans. Comparing MRI brain images of eight Dobermans with CCD to the control group, Ogata found that the CCD group had higher total brain and gray matter volumes, lower gray matter densities in the dorsal anterior cingulate cortex and right anterior insula, and higher fractional anisotropy in the splenium of the corpus callosum (the degree of which correlated with the severity of the behavioral traits). These findings are consistent with those reported in humans with OCD.

“It has been very gratifying to me to use our imaging techniques developed to diagnose human brain disorders to better understand the biological basis for anxiety/compulsive disorders in dogs, which may lead to better treatments for dogs and humans with these disorders,” said Marc J. Kaufman, Ph.D., associate professor of psychiatry at Harvard Medical School and director of the McLean Hospital Translational Imaging Laboratory.

“Canines that misbehave are often labeled as ‘bad dogs’ but it is important to detect and show the biological basis for certain behaviors,” said Ogata. “Evidence-based science is a much better approach to understanding a dog’s behavior.”

The study builds on existing research to better understand the etiology of compulsive disorders in animals such as CCD, which affects Doberman pinschers and other canine breeds. In 2010, researchers from the Cummings School of Veterinary Medicine, the University of Massachusetts Medical School and the Broad Institute at the Massachusetts Institute of Technology identified a genetic locus on canine chromosome 7 that coincides with an increased risk of OCD.

Readers, please share the mental health sagas of your beloved animals here.

This program aired on June 7, 2013. The audio for this program is not available.

Rachel Zimmerman Twitter Health Reporter
Rachel Zimmerman previously reported on health and the intersection of health and business for Bostonomix.