Purdue Veterinarian Studies Compulsive Behavior In Dogs

Andrew Luescher, director of Purdue's Animal Behavior Clinic and one of about 30 board certified animal behaviorists in the country, estimates that 2 percent of the dog population has canine compulsive disorder. Dogs with the disease often display compulsive behaviors such as tail chasing, snapping the air, licking excessively, chewing with an empty mouth and barking monotonously without any change in volume or intonation.

Luescher has seen animals with severe stereotypical behaviors that affect their daily living. For example, one dog stopped drinking water because its shadow was a distraction.

"The longer people allow their pet's behavior to be ignored, the more difficult treatment can be," said Luescher, associate professor of veterinary clinical sciences at Purdue's School of Veterinary Medicine. "Often, behaviors are misdiagnosed as neurological problems. Then the pet owners pay for expensive neurological tests before discovering it's a behavioral problem."

Luescher said a mistake animal owners can make is punishing a dog for behavioral problems, such as canine compulsive disorder.

"The disorder is already a stress- and anxiety-related problem," Luescher said. "Punishment increases that stress and anxiety to the point that the behavior only gets worse."

At the Animal Behavior Clinic, which is affiliated with Purdue's Center for the Human-Animal Bond, Luescher is overseeing two research projects that apply human treatment and diagnostic techniques to dogs.

The first project has recruited dogs throughout the country to participate in a clinical trial to determine how human medication for obsessive-compulsive disorder treats the condition in dogs. A drug, called selective serotonin re-uptake inhibitor, has been successful in treating this disorder in humans.

The Purdue study is evaluating if this medication also will work for dogs. The dogs in the study are placed in a placebo or medication group. Neither the doctors conducting the study, nor the owners, know which treatment group the dog belongs to. After six weeks of treatment, the behaviors of dogs in both groups will be compared.

Luescher said behavior modification should always accompany pharmacological treatment for a behavioral problem. Types of behavior modification differ between each client, and ranges from creating a consistent, predictable environment to distracting the animal with exercise.

The second study looks at how radiological imaging diagnoses canine compulsive disorder.

In the human disease, positron emission tomography, known as PET, is used to diagnose and evaluate neurophysiological brain changes. The images can show which part of the brain is active.

Luescher said some breeds are predisposed to certain compulsive disorder behaviors. German shepherds are more prone to chase their tails, bull terriers tend to have problems with spinning and Doberman pinschers suck their flanks. Larger breeds with the disorder are likely to lick themselves raw.

Other pets -- cats, birds and horses -- also can display such behaviors. The disorder is known to develop from excessive motivational conflict, when the animal is frustrated or stressed, said Mami Irimajiri, who is a doctor of veterinary medicine and is completing graduate work under Luescher.

"We are most concerned about the human-animal bond," Irimajiri said. "Dogs with this erratic, abnormal behavior cannot have a normal relationship with their owners. We also want to improve the quality of life for dogs stricken with this anxiety disease."

Pets' behavioral problems also can lead to physical problems. For example, dogs who lick themselves raw are prone to infection, and a dog that is so disturbed by a repetitive behavior may not be able to eat or drink.