Killed in Action

Bomb-sniffing comes with a risk of death. Luckily, the casualty rate for dogs is lower than you might expect. In all branches of the U.S. military, among all disciplines not limited to bomb-sniffing, 21 dogs were killed between 2005 and June 2011, says Gerry Proctor. The military safeguards its dogs by teaching them to run back to their handlers immediately after finding a bomb.

Sniff, Sit, Repeat

You won't encounter one central school where dogs learn to sniff for bombs, but you will find both military and Transportation Security Administration (TSA) dogs learning to sniff at the huge Lackland Air Force Base in Texas. Dogs usually start training when they are between 1 and 3 years old. In this window, dogs are the most playful and willing to learn, which is essential for them to learn to work [source: Soule].

A puppy's life before training varies. Customs and Border Protection, for example, adopts its 1-to-3-year-olds from shelters and families, while also buying from breeders and breeding its own [source: USCBP]. The military buys from breeders, too, but first screens the dogs almost like human recruits -- with X-rays and exams, and by taking only dogs that are mild, like to search and won't run at the sound of gunshots [source: Air Force].

Dogs learn the basics of sniffing for bombs in between two and four months. They'll undergo testing and retraining throughout their entire careers though to make sure their skills stay sharp. Each agency has its own training program and style. For example, at the TSA's training facility, you'd spot pieces of airport terminals, airplanes, train and subway cars, plus a parking lot filled with cars. The dogs learn a sequence -- sniff the area, find the bomb, sit and get a toy for good behavior -- and must perform it in all of the mock surroundings [source: Soule].

Sounds easy, until you remember that the canine recruits know nothing at the beginning of training. Trainers must coax out each move. The military first teaches dogs to be interested in the smell of explosives. A trainer will hold the smell of an explosive near the dog's nose. If the dog sniffs it, it gets a reward. That's repeated many times. Next, the trainee learns to seek the smells. If an explosive is hidden, and the dog follows the scent, it's rewarded again. This pattern continues until the "sit, stay and pay" routine is built, says Proctor, a spokesperson for the Military Working Dog School.

A fully trained military dog does its routine as if it were natural: It runs ahead of troops, sniffing and upon smelling a bomb, it sits. The troops stop advancing. The dog runs back to troops to get its treat, and an explosive ordnance disposal team disarms the bomb.

Human handlers train alongside their dogs, learning to watch and lead their canines. The cost of training far exceeds a college tuition, although it covers a lot. TSA pays $218,000 in startup costs per dog during training, then $158,000 per year after that, says Greg Soule, a TSA spokesperson. The money covers the salary of the handler, training, certification, veterinary services, kenneling and dog food.

Do you think your dog could pass training? Find out next.