Did you know that a German Shepherd has 220 million Olfactory (smell) receptor cells? Humans only have about 5 million. Did you know that at the ends of these receptor cells there are around 100 to 150 cilia. We only have about six. Cilia are not hairs, even though many people like to describe them like that. They are cellular organelles that are used for movement. These organelles help the dog move scent vapors through it’s nose. A dog also has a wet nose, (our nose is only wet on the inside). The moisture helps trap the scent molecules. The dogs nose is also shaped like a comma. This causes vapors entering the nose to travel in a circular path which increases the travel path through the nose. There is also an organ called a Jacob’s Organ or vomeronasal organ, which is a sacklike organ found in many animals. It is well developed in dogs. These structures not only allow a dog’s nose to detect scent molecules, they allow for separation of those molecules, much the way a gas chromatograph separates molecules in a chemistry laboratory. And finally, a dogs olfactory lobe is very large. It is the size of a walnut in a German Shepherd and only the size of a pea in our brain. So when you see your dog sniffing around, or following an air or ground scent, just realize that we cannot even relate to how well they smell things.