Medical Surveillance of Search Dogs Deployed to the World Trade Center, Pentagon, and Staten Island Landfill*

C.M. Otto, A.B. Downend, J.A. Serpell, L.S. Ziemer, H.M. Saunders, W. Rumbeiha, S. Fitzgerald

Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania
*Supported by the American Kennel Club Canine Health Foundation

In response to the terrorist attacks on September 11th, 2001, the largest search and rescue operation to occur in the United States began. Search and rescue (SAR) canines were deployed to the World Trade Center, Pentagon, and Staten Island Landfill. Long-term medical and behavioral effects of disaster work on SAR dogs have never been evaluated. The data obtained from this prospective health and behavioral study of the dogs deployed to this large-scale disaster will provide critical information that can be used to better prepare future teams. Our monitoring will allow any health problems the dogs may encounter to be identified and treated early, and these dogs will serve as sentinels for health problems that may occur in the human workers at the disaster sites.

The study officially began in January 2002, with 97 SAR dogs that were deployed to the World Trade Center, Pentagon, or Staten Island Landfill. After three years, 55 dogs are still participating. A control population of 55 (now 37) dogs, trained for SAR but not deployed as part of the 9/11 response, are also being monitored to control for any effects SAR training and other deployments might have on the dogs. The handlers complete health and behavior surveys annually. The dogs' regular veterinarians draw blood and obtain chest radiographs, both of which are sent to the University of Pennsylvania for analysis.

After the study's third year, health surveys have found that the deployed dogs have not had any increase in the frequency or severity of medical problems compared to the control dogs. No differences were noted between deployed and controls dogs in the 11 major traits on the behavior surveys. None of the radiographs found clinically relevant lung abnormalities in the first year. Analysis of the complete set of films is pending. Deployed dogs showed an initial stress response to deployment (lower peripheral blood lymphocyte and eosinophil counts and higher blood glucose concentrations) but these differences resolved in years 2 and 3. The deployed dogs also showed a transient response suggestive of exposure to antigens and mild toxins (higher blood values of globulin, bilirubin, and alkaline phosphate). These changes also resolved in years 2 and 3. Despite differences between groups all average values were within normal limits. All dogs were screened for lead, mercury, PCBs, and organic toxins in year 1 and all tests were negative.

As of September 11, 2005, the mortality rate in the deployed dogs (22.7%) is not statistically different than the rate in the controls (16.4%). The frequency of cancer as a cause of death in the deployed dogs (50.0%) is also not statistically different than the frequency in control dogs (44.4%). This rate is not unexpected in companion animals. Despite the fact that two deployed dogs' lives were cut short after being hit by cars and that several of the control dogs were already geriatric when enrolled in the study, the difference in age of death between deployed (9.5 yrs) and control (11.8 yrs) dogs is not statistically significant. Continued vigilance is necessary to determine what, if any, long-term effects will manifest in these heroic dogs.