Puppies chase their tails and chew inappropriate things, and all dog owners take this in stride. But what of dogs who never grow out of these behaviours? In fact, some get more and more obsessive and compulsive about certain actions.
Only recently have clinicians acknowledged that a small population of dogs can actually have an obsessive compulsive disorder. Owners of these dogs say they can’t distract or stop their pets from actions — such as scratching themselves or chewing a paw — even when the dog is hurting itself.
The silver lining? Researchers are not only figuring out this phenomenon, it’s also bringing them closer to the pathways that determine this disorder in humans.
Scientists at the Broad Institute and Harvard University have isolated genes that could lead to this behaviour in dogs. And since dogs are genetically quite similar to humans, there’s a good chance that these same genes could be malfunctioning in humans, too.
“We focus on diseases that dogs and people both get,” said Elinor Karlsson, co-senior author of the study recently published in the journal Genome Biology. “Because the genetic diversity in dog breeds is low — this is why all the dogs in a breed look similar — it is much easier to find the genes that are involved in causing diseases.”
The study started by sequencing and comparing genome sections of 90 OCD diagnosed Doberman pinschers with 60 healthy ones. They searched the genome for regions that differed in the healthy and sick Dobermans, and then compared the questionable areas with those of sick and healthy bull terriers, Shetland sheepdogs, and German shepherds, which are also dog breeds prone to OCD.
Their mapping identified four genes with high mutation rates in the OCD dogs.
“It surprised me that it worked so well! We only needed 16 dogs from four breeds to find four genes linked to dog OCD,” said Karlsson. “In people, we would need to compare hundreds of people with OCD to hundreds of healthy people.”
Additionally, finding a physical underpinning for a psychiatric illness is a huge step in treating it.
“We hope that by understanding the causes of the disease in dogs, we’ll be able to help develop new treatments for dogs and people. We are using the results from our dog work as a kind of clue that tells us where we should look in the human genome,” said Karlsson.