When veterinarian Cynthia Otto was in Manhattan after the 9/11 attacks to support the search and rescue dogs, she heard rumors about the potential impact on the dogs’ long-term health.
“I went to Ground Zero and heard people comment like, ‘Did you hear that half of the dogs that responded to the Oklahoma City bombings died of X, Y, or Z? ‘Or they said dogs responded. September 11th had died, ”she recalls. “It was really unsettling.”
She also emphasized the importance of collecting rigorous data on the health of dogs used in disaster sites. An initiative launched in the weeks after September 11, 2001 did just that, and this week, 19 years later, the results of Otto and colleagues offer reassurance. Dogs that participated in search and rescue operations after September 11th lived on average for a similar length of time as a control group of search and rescue dogs and survived their average life expectancy. There was also no discernible difference in the cause of death of the dogs.
“To be honest, that wasn’t what we expected. It’s surprising and wonderful, “says Otto, director of the Working Dog Center of the School of Veterinary Medicine, of the results in the Journal of the American Veterinary Medical Association.
While post-mortem results showed that dogs used after the 9/11 attacks had more particles in their lungs after they died, that exposure doesn’t appear to cause the animals any serious problems in life. The leading cause of death was age-related diseases such as arthritis and cancer, similar to the control group.
During and immediately after the 9/11 response, Otto and his colleagues contacted the dog handlers to recruit search and rescue dogs for a longitudinal study that will record their health, longevity and cause of death. They recruited 95 dogs who had worked in the World Trade Center, Fresh Kills Landfill, or Pentagon disaster areas. As a control group, they also enrolled 55 search and rescue dogs in the study that had not been used by September 11th.
As part of their participation, the dogs received annual medical exams, including chest x-rays and blood tests. When the dogs died, the researchers paid the dog handlers to allow veterinarians to collect samples of various organ tissues and send them to Michigan State University for analysis. Forty-four of the 9/11 dogs and 19 of the control group dogs were treated post-mortally. For most of the other dogs in the study, the research team obtained cause of death information from medical records or from the dog handlers themselves.
While the team expected to see breathing problems in the exposed dogs – conditions reported by human first responders through September 11 – they did not.
“We expected the dogs to be the canaries in the coal mine for the human first responders because dogs age faster than humans and had no protective gear during the reaction,” says Otto. “But we haven’t seen much that affects us.”
In fact, the mean age of death for 9/11 dogs was roughly the same as for the control group: 12.8 compared to 12.7 years. The leading cause of death in the dogs used was degenerative causes – typically euthanasia due to severe arthritis – closely followed by cancer, although the risk of cancer was about the same as that of control dogs.
Otto and her colleagues have ideas as to why the foreign particles found in some of the dog’s lungs did not result in disease, although they emphasize that it is speculation that is not yet based on data.
“It’s a bit easier to explain the lung effects because dogs have a really good filter system,” says Otto. “Their lungs are different – they don’t get asthma, for example – so it seems that something about their lungs is more tolerant than there is in humans.”
She notes that working dogs tend to be extremely physically fit compared to dogs, which may counteract the negative health effects of working conditions. However, working dog handlers and trainers can always do more to focus on fitness and conditioning, especially as it could slow the progression of arthritis, a disease that played a role in the death of many dogs in the study.
“We know that people who stop moving put on weight and are at higher risk of arthritis. Arthritis makes it painful to move. So it’s a vicious circle,” she says. “The same can be true of dogs.”
The mind-body connection could also help explain the difference between humans and dogs and the longevity of working dogs, says Otto, since dogs don’t necessarily have to worry and experience the same stress after a disaster.
“These dogs have an incredible relationship with their partners,” says Otto. “You have a purpose and a job and the mental stimulation of the training. I suspect that makes a difference too. “
Otto co-authors were Elizabeth Hare and Kathleen M. Kelsey of the Penn Vet Working Dog Center, and John P. Buchweitz and Scott D. Fitzgerald of the College of Veterinary Medicine at Michigan State University.
Article used with permission from the University of Pennsylvania