You’re not alone: Stress may trigger gray hair in dogs too

December 29, 2016

Just as stress and tough times can turn a human’s hair gray, a new study has found the same is the case for our four-legged friends. As explained in a recent article, researchers have found that young dogs whose owners rated them as anxious and impulsive were more likely to have prematurely gray muzzles than dogs that were not regarded as anxious or impulsive.

"Based on my years of experience observing and working with dogs, I've long had a suspicion that dogs with higher levels of anxiety and impulsiveness also show increased muzzle grayness," study lead researcher Camille King said.

To investigate, the researchers traveled to dog parks, veterinary clinics and other venues throughout Colorado, giving questionnaires to the owners of 400 dogs. After the owners answered a 42-item quiz about their dogs' behavior, age and health, the researchers took two mug shots of each dog.

The researchers said they excluded dogs with light-colored fur, as the coloring made it difficult to discern whether the dogs had a gray muzzle. They also excluded dogs that were not between one and four years old, as older dogs could have gray fur simply from aging, the researchers said.

To gauge each dog's anxiety level, the researchers asked questions about the pet's behavior, including whether the dog destroyed things when left alone, whether the dog had hair loss during vet exams or when it entered new places, and whether the dog cringed or cowered in response to groups of people.

Then, to rate impulsivity, the researchers asked whether the dogs jumped on people, whether they could be calmed, if they had a loss of focus and whether they were hyperactive after exercise. Afterward, two independent raters who had never met the dogs graded each photo on a scale of zero to three, with zero indicating no muzzle grayness and three indicating full muzzle grayness.

The article explains that female dogs tended to have higher levels of grayness than male dogs did and that dogs who showed fearfulness toward loud noises, unfamiliar animals, and people tended to have increased grayness. In contrast, grayness had nothing to do with the dog's size, whether it was fixed (that is, spayed or neutered) and whether the dog had any medical problems.

"At first, I was somewhat skeptical of the hypothesis," said study co-researcher Thomas Smith, a professor in the College of Education at Northern Illinois University. "However, when we analyzed the data, the results actually were quite striking."

These findings have practical applications, the researchers noted. For example, if people who work with young dogs notice prematurely gray muzzles, they could alert the owners that the dog might be experiencing anxiety, impulsivity or fear issues. If necessary, the dogs could enroll in behavior-modification programs, the researchers wrote in the study, which was published in the December issue of the journal Applied Animal Behaviour Science.

"This is an original, unique study that has implications for dog welfare," said Temple Grandin, a co-author on the study and a current professor of animal science at Colorado State University.

For more information and photos of some of the dogs studied, click here.

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