Bad dog behavior is sometimes caused by stress and anxiety. Flickr via Creative Commons/rawlands

Dogs that suffer from the canine version of obsessive compulsive disorder have brain abnormalities remarkably similar to those found in humans with OCD, according to new research.

Canine compulsive disorder, or CCD, can cause a dog to compulsively chew or suck on things, or chase its own tail. Unfortunately, some owners may not realize their dog has a complex, and may punish the behavior, thus reinforcing the anxiety underlying the pet’s CCD.

"Canines that misbehave are often labeled as 'bad dogs' but it is important to detect and show the biological basis for certain behaviors," Tufts University veterinarian Niwako Ogata said in a statement. "Evidence-based science is a much better approach to understanding a dog's behavior."

To better understand the roots of CCD, Ogata and colleagues from Tufts University’s Cummings School of Veterinary Medicine, along with scientists from the McLean Imaging Center in Belmont, Mass., scanned the brains of 16 Doberman pinschers -- eight with CCD, eight without. Their results were recently published in the journal Progress in Neuro-Psychopharmacology and Biological Psychiatry.

"While the study sample was small and further research is needed, the results further validate that dogs with CCD can provide insight and understanding into anxiety disorders that affect people,” Tufts veterinarian Nicholas Dodman said in a statement. “Dogs exhibit the same behavioral characteristics, respond to the same medication, have a genetic basis to the disorder, and we now know have the same structural brain abnormalities as people with OCD.”

Some veterinarians think there’s an environmental component that contributes to a dog’s CCD. Under stress, a dog may start adopting abnormal behaviors to cope -- like licking its paws (akin to a person biting his or her nails).

"That's where the compulsive behavior starts," Purdue University veterinarian and animal behaviorist Andrew Luescher told ABC News. "They are comfortable using that behavior, which is totally normal, but if repeated frequently it becomes easier and easier to trigger it. And then they start to show that behavior whenever their anxiety level or arousal level is high enough, regardless of the situation."

Modifying a dog’s environment to reduce his or her stress is key. If the owner can figure what is stressing out his or her dog -- say, a noisy doorbell -- he or she can take some action. Regular walks also go a long way to helping a dog relax. A dog that’s cooped up all day in a house or backyard is like a little kid with cabin fever, according to Luescher.

Dogs with compulsive disorders may also benefit from the drug fluoxetine, more commonly known as Prozac, used to treat a range of human ills including depression, OCD and bulimia. A 2009 trial of 63 dogs with compulsive disorders found that Prozac helped lessen the severity of the treated dogs’ CCD, with only some mild side effects like poor appetite and mild lethargy.

SOURCE: Ogata et al. “Brain structural abnormalities in Doberman pinschers with canine compulsive disorder.” Progress in Neuro-Psychopharmacology and Biological Psychiatry 45: 1-6, August 2013.