The Transportation Security Administration (TSA) is testing a new program at several U.S. airports that uses canines to sniff passengers for explosives in a pre-screening process. Individuals who pass the sniff test can skip long security lines and pass through an expedited security check.

The dog sniffing program is part of the TSA’s voluntary expedited screening initiative. Passengers seem receptive to the pilot program tweeting about their lightening fast security check process that didn’t require them to remove belts, shoes, fluids or laptops.

The improved efficiency of an expedited screening process sounds appealing but at what cost? Are you willing to leave your safety up to the nose of a dog?

An aviation expert explains why Fido beats out machines in screening for explosive substances:

“What are we looking for? We’re looking for things that go boom. The dog takes care of that very, very effectively, and the rest of this is finding pointy objects. Well the only reason we take off our shoes and do all that over stuff is because the other machinery really doesn’t know how to look at it. So this makes a lot of sense for everybody.”

But just how accurate are bomb sniffing dogs and should rely on them?

Earlier this year a GAO investigation found that the TSA was not collecting enough information to assess the training and accuracy of its bomb-sniffing dogs.

"As part of our review we visited two airports at which PSC teams have been deployed and observed training exercises in which PSC teams accurately detected explosives odor (i.e., positive response), failed to detect explosives odor (i.e., miss) and falsely detected explosives odor (i.e., non-productive response)."

In staged TSA tests, dogs had mixed results. In one test, a bomb-sniffing dog accurately identified a passenger carrying explosives where no other individuals were within a few feet of the passenger. In another test, a different dog misidentified which individual carried an explosive device as passengers moving closely together through a busy hallway. That doesn’t make me feel too safe.

Perhaps, in a less “dynamic” environment such as a line where passengers are sniffed individually, the accuracy of these canines improves – significantly. However, the day Fido has the sniffles or gets distracted, could be the day we experience another national tragedy.

The TSA plans to field 120 canine teams at airports nationwide to sniff for explosives on passengers by the end of 2013. These teams are part of an effort called the National Canine Program, which began in 1972 after a bomb threat on a plane and now has over 750 teams of dogs and officers and over $100 million in funding.

I can’t imagine that terrorists –homegrown and foreign- are not busy finding ways to fool the canine sense of smell. And, what about the pointy objects that carry no smells at all like pocketknives, box cutters and scissors? It should be recalled that the 9/11 hijackers didn't carry explosives onto the planes. We can hope that some sort of weapons screening is still included in any expedited security process.

Bomb-sniffing dogs are appealing; they don’t discriminate, have olfactories that demonstrate great accuracy, and are mobile. They aren’t perfect though. Like humans they need training, continual testing, and rest. They want vacations too.

Personally, I would like airports to abandon the invasive body scans and humiliating groping –I mean pat downs– as much as anyone else, but only until we can be assured that any other detection techniques demonstrate consistently high accuracy. We just can’t afford it if a dog has a bad day.