If your neighbor’s barking dog drives you crazy, pity the employees of the nation’s animal shelters, where the noise produced by howling, barking and yapping dogs often exceeds that produced by a jackhammer.
"While employees may wear hearing protectors, dogs don’t have that option," said Crista Coppola, an adjunct instructor in the department of veterinary medicine at the University of Illinois at Urbana-Champaign. "Excessive noise in shelters can physically stress dogs and lead to behavioral, physiological and anatomical responses."
In a paper published in the spring issue of the Journal of Applied Animal Welfare Science, Coppola and co-authors R. Mark Enns and Temple Grandin, both at Colorado State University, describe noise measurements made at an animal shelter built in 1999.
"Noise levels regularly exceeded the measuring capacity of our noise dosimeter, which was 118.9 decibels," said Coppola, who is also a behavior fellow at the Midwest office of the American Society for the Prevention of Cruelty to Animals in Urbana. "These levels were higher than that produced by a jackhammer (110 decibels). The Occupational Safety and Health Administration recommends hearing protection be worn at noise levels above 90 decibels."
A common noise problem in shelters occurs when dogs are placed in gated kennels along the perimeter of a large room. The dogs receive negative stimulation when they see other dogs, especially when they see other dogs receiving attention.
"Dogs are a very social species," Coppola said. "They want to be around other dogs. When they see other dogs, but can’t get to them, you hear a lot of frustration barking back and forth."
A better design places dogs in individual rooms surrounding a common play area, Coppola said. Each room has two doors: One leads into the play area and the other — in the opposite wall — is used by shelter staff to access the room for adoption visits.
"Two or more dogs could be admitted to the play area at a time," Coppola said. "This is a wonderful way to exercise the dogs and let them receive the social interaction they want and need."
Cohabitation is another way to reduce both noise and stress in dogs, Coppola said. Dogs housed in social groups vocalize less, sleep more and show fewer abnormal behaviors. Cohabitation has worked well in Germany and Japan, but has been slow to catch on in the U.S.
Retrofitting shelters can be costly, but even in new construction, noise-abatement designs are often overlooked. Fortunately, in addition to physical surroundings, there are other ways to reduce stress in dogs.
In a separate study, published in the spring issue of the journal Physiology and Behavior, Coppola, Enns and Grandin examined the effect of human contact on stress response of shelter dogs.
In the study, dogs were treated to scheduled human contact, which included grooming, petting and playing, for an average of 45 minutes on their second day in the shelter. A control group did not received scheduled human contact.
To objectively compare stress levels, the researchers measured the amount of salivary cortisol, a hormone recognized as a major indicator of stress response. Dogs that engaged in human contact had much lower cortisol levels on day three than dogs that did not engage in human contact.
"Day three is usually the most stressful," Coppola said. "The dogs have not yet begun to acclimate, and have reached their tolerance level of responding to unpredictable surroundings."
Extra human contact was influential in reducing the stressful effects of shelter housing, Coppola said. "Keeping dogs behaviorally healthy helps keep them physically healthy. And healthy, unstressed dogs have a tendency to be more calm and relaxed."
Excessive noise not only affects shelter animals and employees, it can affect potential adopters, as well.
"Visitors are sometimes driven off by excessive noise," Coppola said. "As we work to reduce that noise, we ask potential adopters to please bear it for the amount of time necessary to find an appropriate dog. Your new pet will thank you."
Funding was provided by Grandin Livestock Inc. and the Eugene V. and Clare E. Thaw Charitable Trust.
University of Illinois at Urbana-Champaign. July 2006.