Does Breeding Impact Dog Behavior?
All domesticated dogs have likely had their behavior and personalities altered as a result of breeding. “Breeding of the brain” has become a catchphrase among some scientists who study dogs.
But first, consider how just spaying or neutering impacts your dog. For example, the ASPCA reports that female dogs can become far less irritable and nervous after being spayed. That’s because un-spayed dogs experience hormonal changes that affect behavior. The surgery can make such dogs act in a more consistent, predictable manner.
Our impact on dogs goes back far earlier than modern surgical techniques. Selective breeding over thousands of years has influenced not only how dogs look, but also what goes on with them internally.
A 2010 study published in the journal PLoS ONE, for example, found that when humans select for differences between skull lengths for breeds, the position of the brain within the dog’s skull can actually shift. To determine this, Michael Valenzuela of the University of New South Wales and his team used MRI to scan the brains of 11 recently euthanized dogs from a local Australian pound, along with two living English springer spaniels.
Analysis of the brain’s overall position in the skull determined that dogs with the shortest skulls -- such as a pit bull, Akita and Shih Tzu cross included in the study group – showed substantial reorganization of the brain. Parts of the brain rotated forward up to 15 degrees, to the point that the sections devoted to scent had shifted position from the front of the brain toward the base of the skull.
That one change alone could affect how dogs perceive their environments. This, in turn, could alter a dog’s behavior and personality. For this and other reasons, animal breeding should be done with care and in a responsible manner.