By Linda Weiford, WSU News
PULLMAN, Wash. – With all the heavy machinery and detection instruments being used to comb through debris at the Oso, Wash., landslide zone, there’s a small wet object getting heavy usage that deserves a closer look.
A dog’s nose.
Whether a dog is a Labrador, beagle or poodle, the scent-detection ability of its nose outdoes any artificial detectors, said Washington State University veterinarian Leticia Fanucchi, who researches the dog’s olfactory system as it relates to canine behavior.
That’s why, increasingly, dogs of varied breeds are being trained to detect everything from bombs and invasive insects to whale scat and diabetes, she said.
“Dogs can pinpoint the most subtle scents, even in challenging environments such as a noisy and crowded airport, a flooded neighborhood or a mud-covered mountainside,” she said.
At Oso, trained teams of detection dogs brought in from around the country have aided in the search effort, sometimes working up to eight-hour days. News photographs have captured German shepherds, springer spaniels, blue heelers and yellow and black Labradors standing atop logs, trudging through mud and perched inside rescue boats.
“All breeds have a highly developed ability to detect and discriminate between smells, but some are considered ‘specialists’ more than others, meaning that they have a strong desire to track, explore and fetch,” Fanucchi explained.
Onward truffles, whales
At our nation’s borders, highly trained handlers channel dogs’ smelling powers to assist in finding everything from explosives and drugs to endangered sea turtles. In Oregon, dogs detect culinary truffles on forest floors. In the Mid-Atlantic region, the U.S. Department of Agriculture deploys its “Beagle Brigade” to hunt down an invasive beetle that’s killing trees.
And hovering from a boat’s bow in the ocean, trained “scat dogs” can locate floating whale feces. Once these are retrieved, scientists can obtain toxins, DNA, stress hormones and diet content to help determine why the endangered whale population isn’t rebounding.
“What’s remarkable is that these dogs can detect the scat from a half-mile away,” said Fanucchi.
How its nose knows
How to explain the canine’s extraordinary gift of sniff?
First, consider that we humans get most of our information from what we see around us.
“But that’s not the case with dogs. Their vision is secondary,” Fanucchi said.
To place ourselves in the canine’s amply odoriferous world, “imagine that every single object we see has its own distinctive scent, and that any given object might have multiple layers of scents,” she explained, using a McDonald’s Big Mac as an example. “If you were to hold it up and smell, you’d detect one uniform scent. A dog would not only detect the scent of beef, but also a scent for the lettuce, another for the cheese and so on.”
This powerful sense of smell developed over thousands of years of hunting for prey and detecting predators, said Fanucchi.
Here’s the result: Dogs possess as many as 300 million olfactory receptors in their noses, compared to roughly six million in humans, she said. What’s more, the region of a dog’s brain that is tasked with recognizing smell is, proportionally speaking, 40 times larger than ours.
The dog is “a creature of the nose,” writes canine-cognition expert Alexandra Horowitz, author of “Inside a Dog” (Scriber, 2009). To help readers appreciate this assertion, Horowitz explains that a dog is capable of detecting one teaspoon of sugar in a million gallons of water.
Another spectacular sniffer
As more dogs are being trained to put their noses to work, a different mammal with an acute sense of smell is entering the detection job market as well:
In regions of Africa and South America, certain species of this long, scaly-tailed creature are being used to detect explosives such as gun powder and TNT. In Tanzania, researchers use the 12-pound Gambian rat to smell tuberculosis bacteria in sputum.
“Rats have excellent noses that are closer to the ground than those of dogs,” said Fanucchi. “They’re also a lot cheaper to train and board than dogs.”
Even so, envision a twitchy-nosed, beady-eyed rat on a harness scurrying up to your suitcase at the airport. Now, imagine it’s a floppy-eared, tail-wagging beagle on a leash.
“Don’t worry. I don’t think rats replace dogs as our primary animal detectors,” said Fanucchi. “Having a strong nose is important, but so is the ability to exhibit behaviors that we humans can easily interpret – barking, pointing, digging, wagging a tail. Dogs prevail, hands-down.”
Leticia Fanucchi, WSU veterinary researcher, firstname.lastname@example.org
Linda Weiford, WSU News, 509-335-7209, email@example.com