I love to go on walks with my dog, but Apollo and I have very different ideas about what the point of a walk should be. I am out for exercise with a side of sunshine and fresh air. Apollo’s goal is to smell… absolutely everything! This leads to conflict. I want to keep moving and Apollo wants to stop, and then walk, and then stop, and then walk…
We all know that a dog’s sense of smell is better than our own, but do you know just how much better? I recently watched a TED-Ed Lesson that starts with an excellent explanation of just how a dog’s nose works:
As your dog catches the first hints of fresh air, her nose’s moist, spongy outside helps capture any scents the breeze carries. The ability to smell separately with each nostril, smelling in stereo, helps to determine the direction of the smell’s source so that within the first few moments of sniffing, the dog starts to become aware of not just what kind of things are out there but also where they’re located.
As air enters the nose, a small fold of tissue divides it into two separate flows, one for breathing and one just for smelling. This second airflow enters a region filled with highly specialized olfactory receptor cells, several hundred millions (300,000,000) of them, compared to our five million. And unlike our clumsy way of breathing in and out through the same passage, dogs exhale through slits at the side of their nose, creating swirls of air that help draw in new odor molecules and allow odor concentration to build up over multiple sniffs.
But all that impressive nasal architecture wouldn’t be much help without something to process the loads of information the nose scoops up. And it turns out that the olfactory system dedicated to processing smells takes up many times more relative brain area in dogs than in humans. All of this allows dogs to distinguish and remember a staggering variety of specific scents at concentrations up to 100 million times less than what our noses can detect. If you can smell a spritz of perfume in a small room, a dog would have no trouble smelling it in an enclosed stadium and distinguishing its ingredients, to boot.
The video goes on to talk about how our sense of sight and hearing present us with a picture of a single moment in time, while a dog can smell “an entire story from start to finish.” It also explains how the canine vomeronasal organ lets dogs “identify potential mates, distinguish between friendly and hostile animals, and alerts them to our various emotional states. It can even tell them when someone is pregnant or sick.”
I had reached what I thought was a pretty good compromise with Apollo on our walks. He got to dawdle at the beginning, but at all other times he was expected to get his nose off the ground and keep up the pace. Now, I think I’ll give him a few more opportunities to stop and smell the roses, so to speak.
Take a look at this TED-Ed Lesson; it will give you a new appreciation for what your dog can do with his nose.
Dr. Jennifer Coates