Dogs devote lots of brain power to interpreting smells. They have more than 100 million sensory receptor sites in the nasal cavity compared to 6 million in
people, and the area of the canine brain devoted to analyzing odors is about 40 times larger than the comparable part of the human brain. In fact, it has been estimated that dogs can smell anywhere from 1,000 to 10,000 times better than people.
Can dogs use smell to communicate?
While noses do not actually speak, they do communicate. With a single sniff, noses interpret an entire story without words by using amines and acids emitted by dogs as the basis for chemical communication. The chemical aromas communicate what a dog likes to eat and identify gender and mood.
By simply smelling, a dog can determine if a new friend is male or female, happy or aggressive, healthy or ill. Dogs get a general idea about each other with a quick sniff, but get more detailed information by getting up close and personal, which is why some dogs sniff private parts of the anatomy.
Dogs also have a good scent memory that can identify other dogs they have not seen for years and even remember which of them was the dominant member of the pair. When dogs belonging to the same family are separated for a while, they use sense of smell to catch up on things. Changes in odors may convey where the dog went, what he ate, and what he did.
When in a new territory, a dog can sniff a tree and determine what other dogs live in the neighborhood. They can smell a visitor’s pant-leg and get a good impression of where the person lives and whether he has pets at home. In addition, humans each have a unique scent that enables dogs to tell one person from another. Our dogs do not need to see us to identify us.
Dogs also have a great homing instinct that depends on their ability to smell. Since dogs move their nostrils independently, they can determine the direction of an odor and use their sense of smell like a compass.
Dogs also sense fear and anxiety via their noses. When we are stressed or scared, we secrete adrenaline, the fight-or-flight hormone, which dogs detect even though we cannot smell it. When we are anxious, we also have increased heart rate and blood flow, which carries body chemicals to the skin surface where dogs can smell them more easily. So there is no use trying to mask your true feelings from your canine companion: their sense of smell will not be fooled. (ED)