So if a dog's nose has that degree of sensitivity, are they able to detect any substance that has an odor? Indeed, how big a part does breed play and are some dogs better at following scents than others? Take the American Pitbull Terrier as an example: Can the American Pitbull smell cocaine?
The answer is a resounding "Yes".
Signs of an American Pitbull Smelling Cocaine
Most detection dogs are trained to be more discrete and make a distinct but subtle action such as lying down quietly or lifting a front paw.
As for narrowing in on the trail of the scent, dogs show two types of search patterns. The first is a more generally sweeping motion where they move quite quickly, often in wide sweeps with their nose a few inches off the ground. What they are doing is picking up scent molecules on the air, and then moving along and taking another sample. The dogs take lots of rapid, shallow sniffs as part of this sampling process. This allows them to work out where the strongest concentration of smell is so that they can track it.
As the smell becomes stronger, the dog slows down and will inhale more deeply. You'll see this is as the dog with their head close to the ground, taking deeper breaths - sometimes with flared nostrils.
If the odor is especially interesting, the dog may even flehmen. This is where the dog raises the upper lip to expose special chemoreceptors that sample the air and send messages about the scent to the brain.
- Head tilting
- Wag tail
- Head down following a trail
- Sniffing deeply
History of Dogs Sniffing out Drugs
The history of mankind making use of canine ability to follow a scent goes far back into the mists of time. Almost as soon as early man realized dogs were good at tracking, they made use of this talent for hunting down prey.
The more refined use of a dog to track down an individual scent, unrelated to prey, came later. It wasn't until the 1940s that dogs were first officially used to sniff out explosives. These dogs were used by the American Armed Forces in North Africa to find unexploded mines. The success of these brave canines and the number of lives they saved made it evident just how useful a trained sniffer dog could be.
Thirty years later, in the 1970s, the use of detection dogs was widespread by law enforcement and rescue services. These dogs were trained to detect substances as diverse as illegal drugs (including cocaine), currency, explosives, and trapped people.
Such was the success of these dogs that use expanded further. In the modern day, sniffer dogs are also used to detect agricultural products containing pest, diseases such as cancer, and they warn diabetics when their blood sugar levels are dangerously low.
Whilst some dog breeds have a better sense of smell than others, the Amercian Pitbull is considered to be right up there with supreme sniffers such as the Beagle and Bloodhound.
The Science of American Pitbulls Smelling Cocaine
Take that nose, for example. The slightly moist surface is designed to trap scent molecules so that they can be inhaled and come into contact with the mucous membranes lining the nose. Once inside the muzzle, the Pitbull has roughly 300 million olfactory (scent) receptors, compared to a mere six million in the human nose. Then, the part of the brain devoted to interpreting those signals, is approximately 40 times larger than in the human brain. All this adds up to a dog sense of smell that is at least 10,000 times more sensitive than a person's.
Such is the sensitivity of a dog's ability to smell that they could detect one rotten apple amongst two million barrels of apples. Amazing!
Training an Amercian Pitbull to Sniff out Cocaine
Professional trainers of sniffer-dogs use a method as devised by the Department of Homeland Security. This involves finding something that motivates the dog, such as a game of tug. The trainer then uses a freshly laundered towel that doesn't carry any scent as a tug toy. The dog is regularly engaged in an active, fun game of tug and praised for their participation.
The next step is to apply a little of the chosen scent (in this case cocaine) to the towel. The trainer then plays a great game of tug using the cocaine-infused towel. This helps the dog to associate the cocaine scent with something that they enjoy doing - playing tug.
Now, the trainer gets a little sneaky and places the cocaine-infused towel next to a clean towel. The dog is ignored if they pick up the fresh towel, but enthusiastically praised and rewarded with a game when they select the drug-infused one.
And so the training continues with the object carrying the cocaine smell being mixed with more and more objects, and even hidden. When the dog finds the target object, they are praised and rewarded. This builds a strong link in the dog's mind with finding a certain scent as a means of getting a great game of tug.
So, all along the dog isn't thinking about finding drugs, so much as pointing out a specific smell that earns them a fun game.
How to React to an American Pit Bull Sniffing out Cocaine:
Drug detection dogs have a job of work to do. Always ask the handler first, if it's OK to approach the dog.