The beagle dog is a four-legged fun fest. Known for their lively personality and friendly nature, these food-motivated, scent driven dogs are a whole bundle of fun. It's pure delight to see a beagle following a scent, nose down and white-tipped tail in the air. Following a scent (and food) is what beagles live for. To them, a scent conveys information in the same way an email or text does to us. Indeed, the odors and smells a beagle follows on a walk are like the doggy version of Twitter.
But what exactly can that sense of smell detect? For example, can beagles detect illicit drugs such as marijuana?
The answer is a most definite "Yes", with no stash being safe from a beagle's nose, even when disguised in coffee or another strong-smelling substance.
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Signs a Beagle has Detected Marijuana
However, sometimes it's more appropriate for the dog to give a silent signal, such as lying down with their nose pointing towards the find. This carries less likelihood of alerting felons that the game is up, and enabling their arrest.
When actively on a scent trail, the beagle moves swiftly in a zig-zag path. The dog takes lots of shallow sniffs as they go, which samples the air and tells the dog where the scent trail is strongest. They then follow this trail to get closer to the stash.
Once close to the target, the dog slows down and takes fewer, but deeper breaths. This helps them hone in on the exact location of the find.
- Tail up
- Ears up
- Tail wag
- Slower, deep-breath sniffing
- Rapid, shallow sniffing
- Zig-zag movement to-and-fro to survey the air
A History of Drug Detection Dogs
Whilst dogs have been used for hunting and following since man and dog first became companions, diversification as sniffer dogs first happened in the 1940s. This was when the American Armed Forces used trained dogs to find unexploded landmines. The program was a big success, saving many human lives.
Moving forward, by the 1960s and 70s, trained dogs were regularly used to sniff out stashes of illicit drugs.
Select the right dog and train them sympathetically and it's possible to teach them to sniff out just about anything, which is that current state of play today with dogs able to detect cancer, low blood sugar levels, or even allergens!
The Science of a Beagle's Sense of Smell
The brain has a finite processing capacity. If one sense (such as smell) is well-developed, this means the relevant processing areas in the brain (the olfactory center) are enlarged. Different dog breeds have different sensory specializations, which is reflected in the size of the brain's processing center for that sense.
The Beagle's sense of smell is so fine-tuned, that if our eyesight was as good as a Beagle's ability to scent, we would be able to see perfectly an object that is 3,000 km away.
The Beagle achieves this feat through a number of adaptations. First, they have a moist, leathery nose, which traps odor molecules so they can be passed up into the nasal cavity. Then the nasal chamber contains scrolls of bone (to increase surface area) coated in mucosa that is especially rich in scent receptors. A beagle's nose contains around 220 million scent receptors, as compared to 2 - 5 million in the human nose.
Next, when the odor molecule has reacted with the scent receptors, neurological messages are sent to the olfactory center in the brain. In a Beagle, around 2% of the brain's processing ability is given over to scent, as compared to 0.03% in the human brain.
All this adds up to mighty sniffing power on the part of the beagle.
Training a Beagle to Detect Marijuana
Training starts by selecting a dog that has a keen nose (such as a Beagle) and a strong urge to play. The handler then engages the dog in an active game of tug using a freshly laundered towel - the idea being the towel has no distinguishing scent on it, but is used to teach the dog that its a great tug toy.
The next step is to impregnate the towel with a little marijuana odor. Then the dog plays tug with this 'smelly' towel and is rewarded with lots of praise. The handler then offers the dog a choice of two tug-toy towels: One is clean and the other has marijuana smell on it.
If the dog selects the clean towel, the handler ignores their request to play. However, if the dog selects the marijuana towel, the handler reacts with praise and excitment, and engages in tug.
Once the dog regularly selects the drug-infused towel, the handler partially hides the towel and encourages the dog to find it. As the dog accomplishes this, the handler slowly makes the game more and more tricky by introducing other clean towels (so the dog has to find the marijuana one) or find the towel that is not in plain sight.
Once the dog has mastered this, they become capable of finding other objects that smell of marijuana, including the drug itself.
How to React to a Drug Detection Dog:
A drug detection dog has a job to do. Never interrupt them while working, and always speak to the handler first, to ask whether it's okay or not to pet the dog.