The Nose Knows
A Dog’s Superior Sense of Smell
A dog’s sense of smell is nearly 40 times greater than our own. Dogs have up to 300 million olfactory receptors compared to our 6 million. They also have a larger portion of their brain devoted to analyzing smells. While a person may notice that their coffee has had a teaspoon of sugar added to it, a dog can detect a teaspoon of sugar in a million gallons of water or two Olympic-sized pools.
What makes a dog’s nose different than a human’s nose? While a human breathes in and smells through the same airways, a dog has a fold of tissue inside of their nostrils that work to separate these two functions. When your dog inhales, the air takes two separate paths that allows them to distinguish scents more easily and definitively. Humans breathe out through the same path as the air that we inhale, but a dog’s nose has two slits on the sides where the outgoing air exits. In this way, the incoming scents and smells are not contaminated by the outgoing air.
We know that much of what dogs learn about their world is understood through their nose, but new research at Cornell University has now documented that a dog’s incredible sense of smell is integrated with their vision, giving us a new understanding about how dogs experience their world. The research team discovered that the integration of a dog’s smell with their vision impacts and influences “how they learn about their environment and orient themselves in it.” Clinical research with blind dogs shows how they can navigate their surroundings much better than humans with the same condition, thus corroborating this new research connecting smell and vision in dogs.
Researchers at Cornell University used MRI scans and advanced neuroimaging techniques to locate that part of a dog’s brain that acts as the information highway. There they found connections between the olfactory system (smell) and the limbic system (involved in behavioral and emotional response) as well as never-before documented connections between the spinal cord and the occipital lobe which is responsible for visual perception including form and motion.
This fascinating new research gives us a better understanding of how dogs navigate, explore, and experience their environment and their surroundings.
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