Now that I think about it, I feel a little silly that I never even knew that dogs could get gray hairs at all. Even more astounding to me is that their grays can come prematurely as a result of stress, just like humans.
According to a study which was published in the journal Applied Animal Behavior Science, premature graying for dogs may be an indication of impulsiveness and anxiety. Interest in the study was sparked when animal behaviorist Camille King noticed that impulsive and anxious dogs seemed to turn gray ahead of when they should.
The study was conducted at Northern Illinois University and involved 400 dogs younger than four, none of which have white hair. Under normal circumstances dogs under the age of four typically don’t have gray hairs.
Two photos of each dog was taken and the owners were asked to fill out a 21-question survey including questions related to their dog's behavior. This is key because because emotional instability and anxiety are associated with stress in humans.
Anxious behavior in dogs is indicated when a dog whines or barks when left alone, or cowers when in the presence of groups of people. Impulsive behaviors can be seen in whether the dog jumps on people when greeting them or excessively tugging on the leash while being walked.
The next phase of the research involved comparing the survey responses with how much gray hair appeared on the dogs' muzzle in their photos. The degree of grayness was ranked from 0 to 3 to indicate no graying to full of grays. Results yielded that dogs' grays were consistent with surveys that indicated high anxiety and impulsive. All this research is good reason to keep your dog stress free.