For the past three years, scientists from MSU and the University of Pennsylvania have been studying the health of 97 search-and-rescue dogs exposed to toxic debris at the Sept. 11 terrorist attacks crash sites.
Because dogs age faster than humans and share a similar physiology, the study could predict possible future health problems in the Sept. 11 emergency workers and volunteers.
"The dogs aren't having serious problems that we can link to 9-11," said Cynthia Otto, lead researcher and an associate professor of critical care at the University of Pennsylvania School of Veterinary Medicine.
The study consists of 97 dogs deployed to the World Trade Center, the Pentagon or the Fresh Kills Landfill in Staten Island, New York where rubble from the World Trade Center was further searched.
MSU veterinary pathologist Scott Fitzgerald received tissues from 12 of the 97 dogs that died to determine what abnormalities were present. He found that other than the production of anthracosis, a black pigment found in animals living in urban or industrious areas, there were no apparent lung abnormalities.
But after comparing results to those who died in a controlled group of non-deployed rescue dogs, Fitzgerald found that the deployed dogs had more cancers and tumors and a 8.5 percent higher mortality rate.
"We're still in the preliminary phase in our study, because humans get different illnesses that dogs don't," Fitzgerald said, adding that the dogs had more unprotected exposure to the debris than workers.
Although current findings show no significant health changes related to toxic debris, Otto said for the general public to assume that all the exposed workers will be unaffected is premature.
"(Other doctors are) following 60,000 people who were exposed. We've got 97 dogs," she said. "If there's a problem that's presently a very low incidence in humans, it might not show up in our dogs."
Other scientists in charge of the study said that current results might not be entirely accurate.
MSU veterinary toxicologist Wilson Rumbeiha found lead, mercury and polychlorinated biphenyls, or PCBs, in samples of toxic debris from the crash sites. Because samples weren't received until three months after Sept. 11, there could have been other substances dogs inhaled at the sites that weren't tested for.
"We don't know everything to look for in the dogs," Rumbeiha said. "We cannot say right now whether the 9-11 sites have done anything.
"However, because the dogs metabolize toxins, some changes in tissue or even DNA may manifest later on."
The study recently received funding to continue for two more years. Scientists in charge hope to complete a seven-year study in total, Otto said.
"Plenty of time to cover a normal dog's lifespan," she said. "Our hope is to find continued good news."
