Rescue dogs breathe easier after 9/11

PHILADELPHIA — In the wake of a recent study concluding 70 percent of 9,500 ground-zero workers suffer extensive health problems, two veterinary scientists note first-responder dogs had no related illnesses.

The reason dogs, until now, appear unscathed is a mystery, experts contend. The sample size might be too small — just 124 Federal Emergency Management Agency (FEMA) and municipal rescue dogs are being studied. But Dr. Cynthia Otto, associate professor of critical care, University of Pennsylvania School of Veterinary Medicine, reports an alternative explanation. Dogs are not prone to asthma, she says, which might shield them from reactive airway disease, the major illness being reported in among rescue workers and volunteers exposed to the Twin Towers' dust and debris.

John Gilkey with Bear post-9/11. The dog eventually died of chronic active hepatitis and a hepatic tumor not attributed to work around the World Trade Center.

"The effects we see in the people aren't manifesting in the dogs, but we're continuing to look," Otto says. "We initially were fearful that the dogs would mostly get chronic lung disease and cancer in large numbers. So far, we have not recognized any dramatic health trends. If these dogs do show a pattern of cancer of something else, we can alert human medicine and try to prevent this in the future."

Second opinion

Otto watches for disease trends in 97 dogs deployed to Staten Island, the Pentagon and World Trade Center against 55 controls. She doesn't directly examine the animals, which reside throughout the country as privately owned emergency volunteers, but compiles data submitted by the dogs' veterinarians.

While Otto's asthma link makes sense to Dr. Philip Fox, director of research and staff cardiologist at Manhattan's Animal Medical Center, he admits, "I don't have a clue." Fox is conducting his own research as veterinarian for the 27 New York City Police dogs first to arrive on scene. Initially the animals exhibited breathing problems, coughing, irritation of the mucous membranes and diarrhea, but five years later they have not developed any obvious consequences outside of what appears normal aging, he says.

Technician turnover

"My dogs have had the harshest exposure, yet so far they're dying according to natural causes as far as I can detect," Fox says. "Has there been a big mortality surge? No. Has there been a surge in disease? Again, the answer is no."

The mechanism that's spared dogs from disease in unknown, and warrants what Fox considers "a whole different research study."

"Clearly people respond differently than many animals to different environmental toxicities and pollutants," he says. "Everyone presumed that the dogs that worked down there would be substantially affected because they were in the midst of toxic smoke and particulate matter and whatever other hazards were at the disaster site. It seemed reasonable that they would become ill. Who knows if there are truly injuries or diseases in these animals we have not yet detected."

Published reports

Evidence to the contrary likely will appear in an upcoming issue of the Journal of the American Veterinary Medical Association. Otto reports her research will show there is no statistical difference in disease incidence, even though her control subjects are younger. "The best, oldest and most trained dogs went to the disaster site," she says. "Yet the cancer rate is the same."

Fox plans to conclude his five-year followup for publication in the near future. Yet he stresses the findings might not provide a solid viewpoint due to the small sample size.

"The problem with all this is that 27 dogs is a very small number of animals with which to try to determine subtle health hazards," he says. "If one had 5,000 dogs to study, that would provide a much more accurate perspective of any potential health consequences."