Perhaps you think of their strong, muscular looks, or maybe their (undeserved) reputation for aggression springs to mind. However, it's unlikely that your first thought is for their sense of smell!
There are many features of a pit bull that distract from the fact that, when all's said and done, they are a dog. They have a dog's senses, including a wonderful ability to hear and a superior sniffing talent, along with poor eyesight for close-in objects and a weak sense of taste.
But how acute is the Pit Bull's sense of smell? Does it allow them to smell marijuana?
The answer is a resounding "Yes, it does."
Signs an American Pit Bull Terrier is on a Scent Trail
How the dog follows the scent depends on how far away the object is. Their behavior is different when the odor is distant, to when it is close by and needs pinning down.
When a Pit Bull first detects an interesting scent, they move forward quickly, usually in a zig-zag path. They take lots of shallow sniffs, which has the effect of taking small samples of air. This allows them to work out in which direction the smell is strongest, and move towards it.
Once the smell becomes stronger and the dog is more certain of the general direction, they slow down. Another difference is the dog takes fewer, but deeper breaths. This helps the dog savor the smell and get additional information such as how long ago the scent was left. Taking these more considered sniffs, the dog has localized the exact spot where the scent is to be found.
Once right on top of the smell, the dog may even perform a third sort of sniffing called flehmen. This involves lifting the upper lip to expose the vomeronasal organ. The latter is a sophisticated scent organ that feeds information directly to the brain about any pheromones within the smell.
- Head tilting
- Tail up
- Curling the upper lip to expose the vomeronasal organ
- Intense concentration
- Rapid, shallow sniffs, followed by fewer, deeper breaths
- Pacing in a zig-zag pattern
A History of Dogs Using Their Noses
The latter group led to the development of scenthounds, or dogs that use their sense of smell to track.
In previous centuries, dogs with a good sense of smell were used for hunting animals and helping their master put food on the table. In later years, this sense of smell has been harnessed in order to find lost people or even to detect illicit substances such as marijuana.
The Science of Sniffer Dogs
The Pit Bull's excellent sense of smell comes from having anatomy finely tuned to detect smells. Even the black, leathery nose is adapted to trap odor molecules by being moist. Once the nose has trapped a molecule, it's then offered up into the nasal chambers when the dog breathes in.
The mucous membrane lining the nasal cavity is especially rich in scent receptors. With such a dense carpet of receptors, this makes the nose extremely sensitive to even the faintest of odors. Indeed, it's said that if our eyesight was as good as a dog's sense of smell, we could see objects clearly that are 300KM away.
Nerves connect the nose to the brain, where a large percentage is devoted to analyzing smells. The olfactory center in a dog's brain is hundreds of times larger than in the human brain.
Combine all these factors together and the result is a super-sense...that of smell! Let's see a character with this super-sense in the next Marvel movie!
Training a Pit Bull to Smell Marijuana
Start by using a clean, odor-free towel. Engage the dog's attention and encourage them to take part in an energetic game of tug with the towel. Praise the dog and make the game interesting so that they want to keep playing.
At the next session, have two towels. But this time, one towel has no odor whilst the other has a faint smell of marijuana about it. Invite the dog to play tug, but let them chose the towel. If the dog picks the unscented towel, ignore them and refuse to play. But if they pick the scented one, praise the dog enthusiastically and engage in tug.
Keep practicing this, so that the dog makes the link between choosing the marijuana fragrance and play.
Now, make things a little more difficult by introducing several towels, but only one has marijuana scent on it. Again, only reward the dog when they chose the correct tug toy. Once the dog has learned to sort through the towels to choose the right one, move the goalposts again.
This time, move the towel a short distance away, so the dog has to sniff it with their nose. Again, praise and reward the dog for a good job when they find it. Once the dog is accomplished at this, hide the towel out of sight. When the dog locates it using smell - bingo! You've trained the Pit Bull to sniff out marijuana.
How to React to a Working Drug Detection Dog:
Sniffer dogs, whether they are scenting out drugs, explosives, or missing people, are doing a job. Never distract them whilst working, and always ask the handler first, if it's OK to fuss the dog.