Dog sense of smell

Unlike humans, dogs do not need to fill up their lungs as they continuously bring odors into their noses in bursts of 3–7 sniffs.

[5] The wet nose, or rhinarium, is essential for determining the direction of the air current containing the smell.

[6] A great part of a dog's brain is dedicated to acquiring and interpreting odors, using its nose as a guide in sniffing in order to follow a trail.

The animal performs a series of short inhalations and expirations, permitting it to bring the odor-bearing molecules in contact with its olfactory mucosa.

These molecules are dissolved and then absorbed by cells of the olfactory epithelium before they reach neurons, which transmit information to the brain.

This supports the theory that dogs process novel information using the right hemisphere of their brain, and the left for reacting to familiar situations.

[9]: 30 Many factors can affect a dog's ability to smell, including age, sex, breed, disease, diet and environmental conditions.

A variety of diseases can decrease a dog's sense of smell, such as canine distemper and nasal mites.

[9]: 91 Humans learned to use dogs' exceptional sense of smell, primarily for hunting but also, more recently, for diverse types of searches.

They can be transported to any crime or accident scene, usually seated at the back of an adapted law enforcement vehicle.

[14] Employed for various purposes in hound-hunting, the hunting dog is above all used for its tracking abilities, that is finding and sniffing out prey.

There are scent work trials available in multiple different countries, which test the dogs ability to find and indicate odours to the handler.

The scents used in these classes, called target odors are: The American Kennel Club has 4 different search environments: Container, Interior, Exterior, Buried.