A decade later, 9/11 search dogs still admired, studied for lasting effects

National Report — They combed through more than a million tons of hazardous debris covering 16 acres with nothing more than a nose to the ground in the days after the Sept. 11, 2001, terrorist attacks on the World Trade Center in New York City, while their human counterparts were outfitted in protective gear.

A decade later, about a third of the search-and-rescue dogs remain—most showing little evidence of ill health despite the prolonged exposure to toxic fumes from the pile. To the contrary, many of the responders who worked at Ground Zero are still plagued with physical ailments and psychological scars from the tragedy.

"It's amazing, because the dogs have done remarkably well," says Cynthia Otto, DVM, PhD, associate professor, research director and associate chair for research in the Department of Clinical Studies at the School of Veterinary Medicine at the University of Pennsylvania.

A bright spot on a dark day: Brought to Ground Zero in the days after 9/11 to help find and recover human remains, Otto says the search dogs did much more. (Photo courtesy od Dr. Cynthia Otto)

Otto has been tracking about 100 of the search-and-rescue dogs called to duty after 9/11. The American Kennel Club's Canine Health Foundation began funding the project in January 2002. Her study involves 97 dogs deployed to the World Trade Center, the Pentagon, and the Staten Island landfill where the World Trade Center debris was taken, and 57 control dogs. The control dogs are search-and-rescue dogs of similar ages and breeds that did not work the post-9/11 cleanup, Otto says.

Each year, the deployed dogs participating in the study are examined by their veterinarians. They in turn send blood samples and chest X-rays to Penn. Also included in the annual update are surveys on behavior and general health that are completed by the dog's owners. If a dog dies, a necropsy is performed and the ashes of the dogs are returned to their handlers, Otto says.

Death and cancer rates in the deployed dogs are roughly the same as in the control group, and there are no signs of respiratory disease, Otto says. Though two more dogs died the week she was interviewed, Otto says the deployed dogs most often succumb to old age—not from problems related to their work after 9/11.

"It's not like these dogs are dying young," she says, adding that most live to 14 or 15 years of age.

"They're phenomenal dogs. There's a smattering of health issues, but not what you would expect," she says.

One of the only health differences noted between the control dogs and deployed dogs was an increased chance of heart irregularities, Otto says.

"That was unexpected, so we are watching that closely," she says. "They are not physical problems, per se, more radiographic changes."

In fact, radiographic cardiac abnormalities were significantly more likely to be diagnosed in deployed vs. control dogs, Otto reports in the Journal of Environmental Health (Sept. 2010). "Of the seven dogs with cardiac lesions, five had mild left-sided cardiomegaly with atrial involvement, one had right-sided cardiomegaly, and one had mild generalized cardiomegaly," she states.

Otto says a study of dogs in Mexico City indicates that enlargement of the heart is a condition that could be triggered by environmental pollutants. "Maybe exposure to the toxic chemicals in the air at Ground Zero set those dogs up for that, but there's no way to say for sure," Otto says. "There is no hard evidence yet."

The study is revealing a lot about the aging process in dogs, as Otto explains there have been few opportunities to follow this number of dogs so closely.

The lack of physical health problems in the deployed dogs may be attributed to the fact that most of them arrived to Ground Zero within two days after the World Trade Center fell, when the major risk factor for human pulmonary complications already had subsided. Still, Otto says ,"the difference between respiratory morbidity in the canine and human rescue workers was unexpected, particularly given the high incidence of respiratory signs in the people and the lack of respiratory protection in the dogs."

Some things the dogs have going for them that humans don't, though, is their resistance to clinical signs of asthma or reactive airway disease. Their longer nasal passages may have more effectively filtered particulate matter and toxins, Otto says.

On the behavioral front, it's more difficult to gauge how the dogs changed after their deployments, because so much depends on the handlers.

"If the dogs are having problems, the handlers are having problems and vice versa," Otto says. "These handlers and these dogs are so intertwined and interconnected, so naturally they are going to respond to each other."

There is no behavioral evidence of long-term depression or post-traumatic stress disorder, like some military dogs have suffered, though some of those dogs appeared to have short-term effects during their deployments.

Again, these effects can be attributed to the handlers, Otto says, explaining that the tone of the work at Ground Zero made it difficult to reward the dogs properly for their finds.

"When they find things, their normal response is to play, etc.," Otto says. "The handlers weren't able to provide the joyous celebration. Most of the dogs were trained to find live humans, and there weren't any to be found there. It was a real emotional challenge to be there and try to be celebratory of a find."

Handlers tried to tone down the praise for the dogs on site, then took them somewhere away from the main search site to simulate finds and offer rewards.

"On-site, the dogs had to deal with the constant intensity of people wanting them to work. When they are searching intensely, they need down time," she says. "They were pushing really hard, and we had to enforce some down time. When they're worn out, they don't smell as well and get injured more. There were all these machines moving big chunks of the pile, people everywhere, the smoke ...

"I can't imagine what the scent picture was for these dogs. To me, the smell was overwhelming," Otto recalls.

Many of the dogs suffered from dehydration and being overtired or over-stimulated, and cuts and scrapes were the top health problem on-site, but only four dogs of all those deployed at the World Trade Center required sutures, she says.

A total of about 300 dogs were called to duty after 9/11, Otto says. Some of the handlers did not respond to requests to participate in the study, she says, and some would not agree to a necropsy.

"These dogs are amazing. They're just true heroes. The people who train them and work with them—most of them are paying their own way. There's really just nothing like it," Otto says.

Still, the work of these dogs following the worst terrorist attack on U.S. soil was priceless, Otto says.

"There is no way those remains would have been identified if the dogs had not been there," she says. "They are the most effective tool we have."

But their contribution to the cleanup process wasn't the only benefit the deployed dogs offered. They were inspirational to the first-responders.

"I have a picture of three firemen that were actually smiling because they were petting a dog. The rest of the time, firemen who were not smiling," Otto says. "The little bit of light the dogs provided—the hope, the comfort—that was a huge part of it.

"They are such a national resource and they're incredible. They really have inspired me to see what dogs can do—emotionally, physically, their ability to be trained. It changes your perspective to the capabilities dogs have."

The events after 9/11 helped bring to light the needs of search-and-rescue dogs, and Otto says veterinarians should work with handlers to develop preventive strategies for dehydration and make recommendations on training and nutrition. More research also should be devoted to the physical and mental demands required of search dogs, and Otto says she is working toward developing a physical working dogs center at Penn.

More information on working dogs and Otto's research can be found at the Penn Vet Working Dog Center's website at pennvetwdc.org.