study of obsessive-compulsive Dobermans might someday help explain similar repetitive behaviors in humans.
Scientists have identified a region on chromosome 7 in obsessive-compulsive dogs that may correlate to the human version of the psychiatric disorder.
Some 2 to 3 percent of humans suffer from OCD, marked by repetitive thoughts and behaviors, such as repeated hand-washing.
Canine compulsive disorder seems to affect certain breeds, notably bull terriers, which can have a tendency to maniacally chase their tails, and Dobermans, which will compulsively suck on blankets or on themselves.
“These are not just funny things,” said Dodman, professor of clinical sciences at Tuft University’s Cummings School of Veterinary Medicine in North Grafton, Mass. “It’s a physically injurious and life-threatening disease and can seriously impair the relationship between owner and dog, which can lead to euthanasia.”
Up to 70 percent of puppies in certain Doberman litters can be afflicted, he said. One German shepherd bit his tail so badly that he bled to death, he added.
Chromosome 7 appears within the cadherin-2 gene (CDH2), which is involved in communication among neurons in the brain.
And cadherins, proteins that enable cells to adhere or stick to each other, are also involved in human obsessive-compulsive disorders. Recently, cadherins were linked to autism spectrum disorder, also characterized by compulsive behaviors, such as repetitive head-banging.
The Tufts researchers teamed up with the Program in Medical Genetics at the University of Massachusetts and the Broad Institute at the Massachusetts Institute of Technology to test Doberman blood samples that the Tufts staff had collected and stored for more than a decade.
Dobermans who (in this case) compulsively sucked on their flanks or on blankets, were more likely to have this gene sequence than healthy dobermans.
Beaver said the findings were “exciting” and that “the number of dogs used in the study places good confidence levels on the findings.”