A dog’s sense of smell is about 1,000 to 10,000,000 times more sensitive than a human’s (depending on the breed). While you have about 5 million scent glands, a dog, depending on the breed, has anywhere from 125 million to 300 million making your dog’s sense of smell 10,000 to 100,000 times better than yours. And the part of a dog’s brain that is used to analyze smells is, proportionally speaking, 40 times greater than a human’s.
Dogs’ noses function quite differently from ours. When we inhale, we smell and breathe through the same airways within our nose. When dogs inhale, a fold of tissue just inside their nostril helps to separate these two functions.
Dogs also have a second olfactory capability, due to the Jacobson’s organ, an organ not found in human. Also called the vomeronasal organ, it’s located in the bottom of a dog’s nasal passage and picks up a variety of pheromones, the chemicals unique to each animal species that signal mating readiness and other sex-related details.
So how good is a dog’s sense of smell? If we used the sense of sight as an analogy, it means that what you can see 1/3 of a mile away, your dog could see 3,000 miles away.
We might notice a teaspoon of sugar in our cup of coffee- A dog can detect that teaspoon of sugar in a million gallons of water. Or one rotten apple in two million barrels.
A drug sniffing dog detected 35 pounds of marijuana that was packed in a plastic container and submerged in a gas tank filled with gasoline.
A cancer-sniffing dog kept returning to a spot on a patient’s skin that doctors had declared cancer-free. A subsequent biopsy confirmed there was melanoma in a small fraction of the cells.
What does this super sense of smell mean for your family dog’s behavior?
It’s why male dogs that have not been neutered can pick up a scent and follow their nose to the receptive female that might be nowhere in the neighborhood.
It’s why your dog knows there’s a treat sitting on a table that is too high up for him to ever be able to see it.
It’s why the local fire hydrant and/or tree, acts as Fido’s Facebook- letting all the dogs know who’s been by.