“It’s really hard to get outside our perspective.”
Because our perception of the world colors our perception of how others see the world, we assume that dogs primarily perceive the world through sight. But its not so hard to understand — and even experience — the concept of smell as a primary input.
“You could think of it as just another perceptual modality,” Horowitz told me. “You can close your eyes. Youre still having an experience as a human, and its transformed in some ways. But theres still a room. Theres still a reality — a room that you can hear, you can smell, you can touch. And even though its not one that were that familiar with, were still co-existing.”
Thats the first way to understand how dogs see the world — close your eyes, maybe cover your ears with sound-canceling headphones. Now take a sniff! As humans, our sense of smell is nowhere near as adept as that of dogs — but you can begin to understand how a dog perceives the world. Maybe you smell something delicious, or something rotting, or the sterile blow of an office air conditioner.
“We basically have a cloud of smell around us. Thats interesting, because it means a dog can smell you before youre really there,” Horowitz said. “If youre around the corner, your cloud of smell is coming around ahead of you.”
“Ultimately, their bigger interest is smell than vision.”
Which isnt to say that dogs dont literally see you — their eyes are another form of input, just not the primary one. “They might look at someone with their eyes; as you approach, they look at you,” Horowitz said. “But then once theyve noticed that theres something with their eyes, they use smell to tell that its you. So they sort of reverse that very familiar use of ours.”
And thats crucial to understanding how dogs see the world.
You, as a human, might smell something delicious and then use your eyes to look around to locate the source of that delicious smell. “Ah, its pasta sauce slowly coming together on a stove!”
For dogs, the opposite is true. Or, as Horowitz put it:
“We smell something and then when we see it were like, Oh yeah, thats it. Thats what it was. It was cinnamon buns. And dogs when they see you, theyre like, Okay, thats something to explore, Im gonna smell it. Oh yeah thats Ben.”
Why do dogs “smell better” than humans?
Unlike humans, dogs have an additional olfactory tool that increases their ability to smell. Jacobsen’s organ (or the vomeronasal organ) is a special part of the dog’s olfactory apparatus located inside the nasal cavity and opens into the roof of the mouth behind the upper incisors. This amazing organ serves as a secondary olfactory system designed specifically for chemical communication. The nerves from Jacobsen’s organ lead directly to the brain and are different from the other nerves in the nose in that they do not respond to ordinary smells. In fact, these nerve cells respond to a range of substances that often have no odor at all. In other words, they work to detect “undetectable” odors.
Jacobsen’s organ communicates with the part of the brain that deals with mating. By identifying pheromones, it provides male and female dogs with the information they need to determine if a member of the opposite sex is available for breeding. It also enhances a newborn pup’s sense of smell so he can find his mother’s milk source, and allows a pup to distinguish his mother from other nursing dogs. With a quick sniff, a pup placed between two females will migrate to the mother that gave birth to him. Pups also have heat sensors in their noses that help them locate their mothers if they wander away.
The two separate parts of the dog’s odor detection system, the nose and Jacobsen’s organ, work together to provide delicate sensibilities that neither system could achieve alone. When the dog curls his lips and flares his nostrils, he opens up Jacobsen’s organ, increases the exposure of the nasal cavity to aromatic molecules and essentially becomes a remarkably efficient smelling machine.