“As we see the world, the dog smells it.”
“Dogs have more genes committed to coding olfactory cells, more cells, and more kinds of cells, able to detect more kinds of smells.” (Alexandra Horowitz, Inside of a Dog What Dogs See, Smell, and Know) So, a dog smelling a doorknob detects combinations of sites, not a single site.
“We might not notice if our coffee’s been sweetened with a teaspoon of sugar; a dog can detect a teaspoon of sugar diluted in a million gallons of water: two Olympic-sized pools full.” (Horowitz)
Or, as a leading canine trainer of bomb-sniffing dogs, Zane Roberts, says:
“When you walk into a kitchen where someone is cooking spaghetti sauce, your nose says aha, spaghetti sauce. A dog’s nose doesn’t say that. Instinctively, it says tomatoes, garlic, rosemary, onion, oregano.” (Joshua Levine, The Education of a Bomb Dog, Smithsonian, July-August 2013)
Unlike us humans, breathing and smelling are not all mixed up. “When air enters a dog’s nose, it splits into two separate paths – one for breathing and one for smelling. And when a dog exhales, the air going out exits through a series of slits on the sides of a dog’s nose.” It is believed that the exhaled air helps new odors enter. Dogs can also wriggle each nostril independently, which helps them find exactly where a particular odor emanates from.
Although dogs are not the best sniffers in the animal world, they shine because of their attitude. Perhaps the elephant, which does have the best nose could be trained to sniff bombs, but logistically, it would not work. Rats and mice and especially jackals smell at least as well as dogs.
The best dogs for bomb sniffing are not necessarily the best sniffers either. Bloodhounds are not smart enough. Golden retrievers have the best noses, but if they don’t want to work, they won’t.
The best breeds have the best work ethic: German shepherds, Belgian Malinoises, and Labrador retrievers. Shepherds will work for play; labs for food rewards. However, shepherds accept criticism; labs don’t.
Bomb dogs are pervasive now – after 9/11 and much better accepted in bank buildings than someone with a bullet-proof vest and an automatic weapon. The terrible bombing at the Boston Marathon leads a security officer there to predict that there will be a whole new look at canines.
In our civilian world, the dog’s job is not so much finding a bomb, but deterring them. The situation is quite different in Iraq and Afghanistan, where they find bombs regularly. Some dogs work for love, praise, food, but “the best bomb dogs are the dogs that really like to play.”
Unfortunately, in the battle zones, it isn’t all play. Army veterinarians began seeing in 2007 what can only be called canine post-traumatic stress disorder. And, the number with canine PTSD has increased to between five and ten percent of dogs on the front line. Half can be treated and returned; the others are retired. (Smithsonian, July-August 2013)
That superb sense of smell that makes dogs unequaled at bomb sniffing means your dog observes the world through that sense as opposed to us sighted humans.
Alexandra Horowitz suggests taking your dog for a smell walk – not “to make good time; not to keep a brisk pace; not to get to the post office.” Let the dog inhale smells, choose the way at every intersection, even though no progress in our sense is made.