University Park, Pa. – During the 13 years that veterinarian Nancy Dreschel was in private practice, she saw a lot of dogs that were severely frightened by thunder and lightning storms. So when she got the opportunity in 2003 to conduct research on what might be done to help animals suffering from this problem, she jumped at it.
"They can really freak out," said the instructor in the Department of Dairy and Animal Science in Penn State's College of Agricultural Sciences. "Some pace the floors nervously, while others will hide or chew the woodwork. I even had one patient crash through a closed second-story window in total panic."
Early in her research, Dreschel concentrated on finding a way to measure the dogs' stress levels. Observing that stressed dogs pant and drool, she collected saliva and measured the amount of the hormone cortisol in dogs frightened by storms.
"The level of cortisol in saliva increased tremendously in frightened dogs during storms, and the levels stayed high for a long time afterwards," she said. "Initially we were surprised that it increased as much as it does and lasts as long as it does."
Although the study was small -- involving fewer than two dozen dogs -- her early efforts received a lot of attention, even meriting a 2005 story in the New York Times. "I think many people could identify with the study because so many of us have encountered or owned dogs that are really bothered by storms," she said.
"Thunderstorm anxiety in dogs is a complicated but very common problem, with reports of 15 to 30 percent of pet dogs affected. I wanted to better understand factors influencing the stress response in anxious dogs. Some dogs know when a storm is coming hours before it arrives, and some dogs respond to flashes of light. But by far, most respond to the sound of thunder.
The study looked at the physiological and behavioral symptoms of dogs that are stressed by storms, even including an epidemiological survey to see if dogs that suffered from storm phobia had shorter lives. The jury is still out on that aspect.
"One interesting conclusion from my early work is that dogs that were around other dogs seemed to be less stressed physiologically by thunder and lightning storms, and the stress didn't last as long after the storms were over," Dreschel said. "So we suspect that there may be something about living with other dogs that makes it easier for the animals to respond to stress."
Recently Dreschel, whose thesis for her doctoral degree in Biobehavioral Health at Penn State was titled "The Biobehavioral Effects of Stress Related to Fear and Anxiety in Domestic Canines," has taken her research to its logical conclusion. She is now investigating ways to reduce stress suffered by dogs that fear storms.
"What we have seen is that dogs stressed out by storms are pretty much inconsolable by their owners, so we are looking at interventions -- treatments to keep stress from increasing so much," she said. "We are now studying the effect of different aromatic compounds on storm-phobic dogs' stress levels."
The most promising substance being tested is called dog-appeasing pheromone, which is emitted from the cleft between the mammary glands of mother dogs and is thought to have the effect of soothing puppies. Scientists believe it may have the same effect on adult dogs that are afraid of thunder and lightning storms.
"Right now we are in the data-collection phase," she said. "Dog-appeasing pheromone has been isolated and reproduced synthetically, and it seems to have a direct effect on their brains to calm them down and reduce stress. This is another fairly small study involving just a few dozen dogs around central Pennsylvania that are afraid of thunderstorms."
The methodology of the study is simple and straightforward -- and troubling to some.
The dog-appeasing pheromone and a few other compounds are applied to bandannas that are tied around participating dogs' necks. Then the animals are subjected to loud recordings of thunderstorms. The animals' behavior is observed, and their salivary cortisol levels are measured to determine their stress levels.
"Everything is standardized -- owners use boom boxes that we provide, and the dogs' surroundings are similar," Dreschel said. "The simulated thunderstorms last five minutes. We have not had any long-lasting effects from our experiments. Animals that fear thunderstorms sometimes have day-long effects from real storms, so the five-minute simulated storms are pretty minor.
"Most owners say, 'Storms stress out my dog so much that if we can learn something to help dogs with this phobia, it will be worth it.' Most say, 'If there is anything out there to help other dogs with this problem, I want to get involved and help.'"
Dreschel hopes to have results within a year or so, and she is optimistic that the dog-appeasing pheromone can offer storm-stressed dogs some comfort.
"There is a lot of anecdotal evidence out there, but the question is whether it really calms them down physiologically," she said. "We need to learn whether what works on one dog will work on another."