Updated: Oct 17, 2018
The sense of smell for us dogs is our predominant sense. Did you know that dogs have about 300 million olfactory receptors cells, compared to humans that only have about 5 million? Each of our nostrils can smell individually, allowing us to distinguish the direction of a particular scent. The old air exits through the slits on the side of our nose, as new air is inhaled through the nostrils allowing us to take in scent continuously. In addition, we have a secondary organ called the vomeronasal (or Jacobson’s organ) that lets us detect pheromones and other chemicals. If you see us chattering our teeth and drooling a bit, you are catching us using that secondary organ to decipher the different components of a scent. A sizable portion of our brain is used to process scent. We can detect smells at concentrations of 100 million times less than that which a human nose can detect. Therefore, we make good hunters and are used for sniffing out drugs and other dangerous materials and even finding missing people.
Sniffing is important as we survey our environment. If you pay attention, you can see our body changes as we decipher the scent sometimes using other inputs to aid in determining the source and safety of the situation. At times we will pause and subtly curve our body away from an object as a warning we don’t like it. When we are unsure about something, we slow down and sniff to help us assess the situation. So, sniffing is part of how we communicate to one another and to people.
Check out these resources for more information on how and why we sniff.