Even in an era of high-tech crime-fighting, the best line of defense against a Brussels-style attack on airports and subways has four legs and a tail. The AP reports that dogs, with their exquisitely sensitive noses, have been trained in recent years to pick up the scent of explosives on people moving through crowded concourses, and so far they have proved a better early warning system than anything engineers have come up with. But experts say there are not enough dogs capable of following the vapor from explosives to go around. Only about 130 have gotten the patented training nationwide since its development about a decade ago. And only one dog is in Europe, according to the chief trainer.
The NYPD's newly graduated class of eight "vapor wake" dogs underwent 15 months of training to sniff out explosive particles in the heat plume left by humans as they walk through a crowd, then follow the scent to the source. They're different from traditional bomb-sniffing dogs trained to smell a stationary object. A dog has 200 million olfactory sensors in its nose. By contrast, the human nose has 5 million. Even though dogs get tired and distracted, no technology can match one, officials say. Demand for "vapor wake" dogs, which cost about $49,000 each and need to be retrained to sniff new explosives yearly, is on the rise due to the threat of suicide bombings. It seems everyone from law enforcement to sports teams and theme parks wants one. (Read more bomb sniffing dog stories.)