May 4, 2009
To three Gettysburg College students, dog drool is something to study.
Biology majors Kelly McConville, Ashton Trawinski and Carly Yaeger spent their senior year collecting saliva samples from dogs to measure the canines' stress levels.
In the fall, they used those samples to compare the levels of cortisol – a stress hormone – of dogs owned by their professors to the levels of dogs in shelters.
"We found that dogs in shelters, on average, had two to three times more stress hormones than dogs in permanent homes," said Trawinski, from Lavellette, N.J.
Some dogs had as high as six times more stress.
Their classmates chose to measure stress levels in people. One of them tested cortisol levels in voters on Election Day in November and found Democrats were more stressed than Republicans.
Trawinski and her two friends have post-graduate plans to further their studies of animals, so they preferred to use canines as their research subjects. The trio, nicknamed "dog girls" on campus, decided to launch an independent project in the spring semester to probe a little deeper into what caused their furry shelter friends so much stress, which in turn, affects their health.
They learned to use dental rope to collect saliva. They would put the rope in a dog's mouth and then tempt it with a treat. Once the dental rope was saturated, they placed it in a syringe and squeezed the saliva into a test tube, so cortisol levels could be measured using an acid test. That proved to be a lot easier than using an eye dropper, which is what they used last fall.
They visited five area shelters, including the Humane Society of the Harrisburg Area, 24 times and collected 105 saliva samples from 27 breeds of dogs. They determined age, sex and breed alone didn't seem to affect stress levels, but shelter conditions and an animal's background did.
"Shelters that are more overcrowded have dogs with more stress, and dogs in shelters that are better funded have lower stress," said McConville of Damascus, Md.
Dogs that were turned over to shelters by owners had higher stress levels than stray dogs, said Yaeger, of Waukesha, Wisc.
For strays, a shelter generally is a better situation than living on the street, Yaeger said.
"But for a dog to go from living in a home to living in a shelter ... that's a much more detrimental situation," Yaeger said.
Amy Kaunas, executive director of the Harrisburg humane society, says the research might promote other shelters to open a behavioral-care unit as she did two years ago. The unit monitors stress in the animals and allows the shelter to be pro-active about reducing it, she said.
"We are becoming more aware, as a society, that animals experience a full range of feelings, and the fact that dogs can feel stress is part of that movement," Kaunas said.
The three biology seniors in this article started their research project as a component of a Comparative Animal Physiology course that was taught by Prof. Kay Etheridge. She continued to oversee the students' independent research through the spring semester.