Should TSA let airport passenger screening go to the dogs?

It's time to send bomb-detecting dogs sniffing up and down lines of passengers at airports, say some security analysts. Dogs may reduce the need for TSA screening that is more invasive of personal privacy.

Is there a friendlier, tail-wagging alternative to explicit body screens and "enhanced" pat downs of the flying public?

So far, being nosed by an explosive-sniffing dog is not an option for travelers at airports, who for security reasons are now being screened via the high-tech scanners or intrusive pat downs. But some passengers and security experts say it's high time to send dogs sniffing up and down airport lines, perhaps reducing the need for methods that are more invasive of personal privacy.

For decades, canine explosive-detection teams have been used to screen air cargo on passenger flights. The US military uses dogs in Afghanistan and Iraq. In June, the European Union for the first time approved use of explosive-sniffing dogs to screen airline passengers. Bomb-sniffing hounds already pad aisles on Amtrak and many US commuter-rail trains.

VIDEO: TSA chief Pistole says no immediate changes to airport screening

"Dogs would be a wonderful solution," says Jeffrey Price, co-author of a textbook on aviation security and chief of Leading Edge Strategies, a security consulting firm in Denver. "They're much friendlier than some of the current processes – and yet, if you're hiding something, the last thing you want to see is a dog."

Bomb-sniffing dogs could improve passenger screening and explosives detection, while reducing concerns about privacy and radiation exposure, some US security experts say.

And Congress, after the 9/11 attacks, mandated increased use of explosive-detection dogs. By 2008, the Transportation Security Administration (TSA) had deployed 370 certified canine explosive-detection teams to 69 airports and 56 teams to 14 mass transit systems, the Government Accountability Office reported. That year, TSA's aviation canine explosive detection teams received $36.3 million in funding.

Today, more dogs than ever are sniffing for explosives in the US transport system, though TSA will not say how many teams now scan air cargo, specifically.

"More than 750 TSA-certified explosive detection canine teams are deployed to mass transit systems, airports and cargo facilities," says Greg Soule, a TSA spokesman, in an e-mailed response to questions. "These teams are a highly effective, mobile layer of security to detect explosive materials in various transportation environments."

But TSA has not approved use of dogs for routine passenger screening in airports. Why?

Concerns about costs and passenger resistance (whether possible allergic reactions or fear of being bitten) top the list. Training a single dog and the dog's handler can take 10 weeks or more, not including regular recertification. Moreover, real explosives must be used to train dogs, which can be both inconvenient and potentially hazardous.

One big concern, Mr. Price notes, is that explosive-sniffing dogs are effective for only one or two 30-minute sessions a day. They may become ineffective after that, mostly because they get bored, he says. Their record is not perfect, either. Earlier this month, bomb-sniffing dogs in England initially failed to detect bomb material hidden in printer cartridges shipped from Yemen. Three bomb-sniffing dogs assigned to inspect cargo at Philadelphia International Airport earlier this year were reported to fail recertification tests.

"Explosive-detecting dogs are held to a higher standard of performance than other types of dogs, like narcotics-detecting dogs," Price says. "If a dog misses drugs getting on a flight, that's not a huge problem. If a dog misses some explosives, that's a major issue."

Even so, dogs' noses are as sensitive as any mechanical explosive detector now deployed and can detect trace amounts of scores of explosive vapors. Unlike machines, a dog can track a suspicious scent to the source. They also work cheap – for a little kibble and the praise of their handlers. Bomb-sniffing dogs are not necessarily breeds that present a fearsome posture to travelers, but include beagles, Labrador retrievers, and familiar guard dogs such as the Belgian Malinois.

The number of dogs required to sniff at least 2 million domestic airline passengers a day would be large, acknowledge Price and others. There would need to be a huge force of such dogs, not to mention kennel space near airports.

TSA cannot rely solely on dogs from its Canine Breeding and Development Center at Lackland Air Force Base in Texas, canine explosives experts say. Many dogs are purchased from private breeders. Even so, only a handful of canine teams are available per mass transit system, and they are spread thinly just for sniffing cargo, some experts say.

It's not known which method would be cheaper: scanning machines or trained dogs. TSA has conducted some passenger-screening tests using dogs, but it has not done any comprehensive pilot study to see how dogs compare overall with body scanners on costs and detection rates. Machines can cost $150,000 or more.

"I'm not saying we should rely solely on dogs, but there's no question they can provide great deterrence in passenger screening," says John Pearce, associate director of the Canine Training Center's Animal Health Performance Program at Auburn University in Alabama. "How do you calibrate a dog's nose? A terrorist can calculate a lot of things about mechanical detectors, but concocting a plot that deals with a dog's nose gets complicated for them."

Mr. Pearce's center specializes in "vapor wake detection," which trains a dog to detect and track an explosive's odor to its source, even in a crowd. A VWD dog, he says, can also sample a plume of air coming off a person or that person's bag as he or she passes a choke point.

Diag-nose, based in Britain, shows on its website a picture of airport crowds filing past an explosives-detecting dog – the dog separated from the people by a plastic sheet perforated with holes. The dog sniffs the air passing through the holes and alerts the handler if it detects something.

"Dogs are really relatively inexpensive compared to other forms of technology out there," says Pearce, whose canine-training center is talking with TSA about using vapor wake dogs for airport passenger screening. "To those who say dogs can be used for only 20 to 30 minutes before taking an hour break, I would say that dogs can work much longer if they are trained to do it, just like long-distance runners."

There is at least some anecdotal evidence that dogs would be accepted – even preferred – by air travelers.

"Why not the use of trained dogs instead of pat downs and body scanners," writes one anonymous commenter in a Facebook debate, one of several on the Internet pitching dogs as a solution to the privacy-protection conundrum. "Much cheaper and far less invasive."

Writes another contributor on Yahoo.com: "Dogs could detect everything those scanners do and more. Why not make them standard at every airport gate?"

VIDEO: TSA chief Pistole says no immediate changes to airport screening