Olfaction (Smell)

Dogs have a better sense of smell.
Dogs can detect a drop of acetic acid diluted thousands of times.
The capability of the dog depends on the breed.
Dogs have 125->300 million olfactory receptors.
Cats have 100 million olfactory receptors.
Some dogs have been selectively bred for the ability to detect scents (e.g. blood hounds and beagles).
Dogs have been trained to detect a wide range of odour from narcotics and explosives to human sweat and even cancer.
Dogs can distinguish between two different types of scents: an air scent and a ground scent..
Air scent is intermittent so less obscured by competing scents.
Ground scent is relatively permanent, but can be contaminated by other scents.
Dogs and cats have several mechanisms to aid olfaction:
Sniffing behaviour - disruption of normal breathing with rapid and short inhalations and exhalations, air is forced into a space above the subethmoidal shelf and traps the air.
They both have a vomeronasal or Jacobsen's organ.
This is a pair of fluid-filled sacs situated just behind the upper front teeth in the roof of the mouth.
It is connected via nerves to the amygdala region of the hypothalamus.
Highly sensitive to airborne pheromones and allows the animal to taste the smell.
Cats have a Flehmen response.
This is a behaviour we see when they are focussing on a smell.
The cat raises its head slightly, draws back its upper lip and opens it mouth a little, sniffs and concentrates for a few moments.

	Created by Sophie Mae Neash over 10 years ago

University Companion Animals Note on Canine and Feline Senses and Communication, created by Sophie Mae Neash on 29/11/2013.