But why is this? Is there something about the Bloodhound's sense of smell which makes it unsuited to sniffing out substances such as ecstasy, marijuana, or illicit drugs?
Actually, no. The Bloodhound has an extraordinarily sensitive sense of smell and is just as able to smell a drug, such as ecstasy, as a missing person. All it takes is for the dog to be trained to know that the scent they are to find is that of ecstasy.
Signs a Bloodhound is Following a Scent
To start with, the dog is likely to scent the air, picking up the faintest of odors. This involves taking rapid, shallow breaths, which acts as a sampling technique to see what odors are around. They also move their head from side to side to work out where the smell is strongest.
Once they've detected a promising direction, the dog moves forward quickly, taking those rapid sniffs as they go. Again, this helps steer the dog close to the source of the scent. Once the dog is getting close, their pace slows down.
Indeed, they're sniffing pattern changes to one of fewer, but deeper breaths. This is equivalent to studying the scene, to get further clues as to the exact location of the item and how fresh or old the scent signature is. As the dog hones in, they're liable to become excited. Indeed, the Bloodhound is known to howl as they zero in - out of pure excitement!
- Head turning
- Tail up
- Nose to the ground
- Baying or howling
- Rapid, shallow sniffing, followed by fewer, but deeper breaths
- Zig-zagging from side to side
A History of Bloodhounds
The original purpose of the Bloodhound was to follow the scent of wounded wolves or deer. Indeed, packs of Bloodhounds were common, with the aristocracy or wealthy clerics having kennels devoted to them.
However, as the centuries passed, wolves and deer became less common and the need for a heavy hunting dog declined.
Instead, those wealthy enough to enjoy hunting as a pastime switched attention to the fox. This required an altogether faster dog, and so the Foxhound came to the fore.
In the meantime, the faithful Bloodhound still had a place, but as a tracker of poachers and felons, rather than animals.
The Science of Bloodhounds Sniffing
Let's start with the dog's external anatomy and their nose and ears (yes, ears!).
That black, leather nose is slightly moist which helps to trap odor molecules and make them available for the nasal chamber. And when the dog runs nose to the ground, those long floppy ears set up micro-air currents which waft scent molecules towards the nose.
Inside the nasal cavity, it is lined by a moist mucous membrane which contains around 300 million olfactory receptors. This compares with a measly two million receptors in the human nose.
But the specializations don't stop there. The processing center in the brain, the olfactory center, represents a relatively large percentage of the space in a canine brain when compared to people.
All in all, this adds up to a dog's sense of smell being at least 10,000 times more sensitive than a human's. To put this in perspective, it's estimated that a dog could sniff out one rotten apple from amongst two million barrels.
Training a Bloodhound to Smell Ecstasy
To do this, start by encouraging the dog to play tug. Use a clean, scent-free towel, so that this acts as a blank canvas. Play tug with the towel, and enter into the spirit of the game so the dog really enjoys it.
Next, do this again, but after having rubbed the scent of Ecstasy onto the towel. Praise and reward the dog for joining in the fun.
Now, make things a little more tricky by introducing a second towel. Place them both on the floor and let the dog choose which to play with. But here comes the catch. If the dog chooses the new, unscented towel, ignore them and refuse to play. Only react when the dog selects the ecstasy-scented towel. Praise the dog and engage in a great game of tug.
Keep offering the dog this choice. Once the dog is reliably selecting the correct towel, you are ready to move on. Next, place the ecstasy-laced towel in a heap with others. But remember the golden rule of only rewarding the dog for selecting the correct one!
Again, once the dog is regularly singling-out the correct item, it's time to place that towel close-by but out of sight. Now the dog has to use their nose in order to find the hiding place. And so begins the skill of tracking a specific scent to find the source object.
How to React to a Working Bloodhound:
A Bloodhound with a handler may well be working. It's important not to distract the dog and divert their attention by fussing them. If you want to stroke the dog, first approach the handler and ask if this is okay.