The human body is incredibly sensitive to stress.
Stressful experiences manifest both psychologically and physically. One of the most telling and immediately apparent of these indicators is premature graying.
University of Northern Illinois (NIU) alumnus Camille King and NIU professor Thomas Smith teamed up with animal behaviorist Peter Borchelt and famed author, researcher, and professor of Animal Science at Colorado State University Temple Grandin to study the relationship between stress and premature graying in dogs.
The team examined 400 dogs from dog parks, dog shows, veterinary clinics, and other locations around Colorado. They administered dog behavior questionnaires to the dogs' owners, and took photographs of the dogs on-site. Independent raters then used those photos to rate the level of muzzle grayness in the individual dogs.
The findings were telling. Dogs between the ages of one and four whose owners reported behaviors associated with anxiety displayed more premature muzzle graying than dogs reported as less anxious. In addition, female dogs were more prone to premature graying than male dogs, and higher levels of graying occurred in dogs whose owners reported impulsive behaviors. Other variables such as dog size, underlying medical issues, and spay/neuter status did not play a significant role in predicting levels of muzzle graying.
The results confirmed what King suspected based on years of interaction with dogs, but surprised Smith, the team methodologist and statistician.
"At first, I was somewhat skeptical of the hypothesis. However, when we analyzed the data, the results actually were quite striking," he said.
The study was published in the journal Applied Animal Behaviour Science and you can check it out here.
WATCH NOW: Pets Lead to Good Health