Man's best friend can also suffer from obsessive compulsive disorder, say scientists who have identified four genes that are connected to OCD in dogs.
Researchers said few breeds of dogs exhibit particularly high rates of OCD. These include Doberman Pinschers, bull terriers, Shetland sheepdogs and German shepherds.
OCD is an anxiety disorder characterised by intrusive thoughts that produce uneasiness, apprehension, fear, or worry; by repetitive behaviours aimed at reducing the associated anxiety; or by a combination of such obsessions and compulsions.
Dogs with OCD may display behaviours such as incessant tail chasing, repetitive shadow stalking and relentless paw chewing.
Since dogs are genetically simpler than people, researchers turned to these canines in their search for OCD-related genes, 'Discovery News' reported.
Elinor Karlsson, a computational biologist at the Broad Institute at Harvard University, and colleagues began by sequencing and comparing a large section of the genomes of 90 Dobermans that had OCD with 60 that didn't.
They also searched for genes that looked the same in all of the Dobermans but that differed between that breed and others.
When they had zeroed in on several suspicious areas of the genome, the researchers compared the suspect Doberman genes with genes from a sample of the three other breeds that also suffer higher-than-usual rates of OCD.
Those analyses pinpointed four genes that have unusually high rates of mutations in dogs with obsessive and compulsive behaviours.
The genes implicated in the new study play roles in pathways that have also been connected to human OCD, Karlsson said, suggesting that dogs could provide a helpful model system for developing better treatments for people.
The study was published in the journal Genome Biology.