Pet Tips

Dog Noses – Tip 92

Has your dog ever sniffed the air or ground and then seemed to follow some predetermined path you can’t see? Your dog’s sense of smell is one of the primary senses he/she uses. The anatomy of the nose and the process of smelling, or olfaction, allows the dog to pick up on scents that humans are unable to detect. As a result of this, we use the dog’s superior sense of olfaction to help us with detection and in sport.

Compared to humans, the sense of smell is a thousand times more sensitive in dogs and this can be explained by looking at the anatomy of a dog’s nose. The numbers of olfactory receptors, which actually detect odours, are more numerous in dogs than humans. Dogs have 220 million of these receptors whereas humans have 5 million. No wonder your dog can find the little food tidbits left under the sofa! The olfactory receptors are found in the nasal cavity, and are spread throughout the nasal bones. In this region, there are also a high number of olfactory nerves, which connect to the well-developed olfactory lobe in the brain. It is here where the dog processes the scents and decides which ones are worth pursuing. Unlike humans, dogs have another olfactory chamber, called the vomeronasal organ. This organ is a pair of fluid-filled sacs above the roof of the mouth and the olfactory receptors found here differ slightly from those found throughout the nasal bones. The receptor cells in the vomeronasal organ can also communicate with the part of the hypothalamus responsible for sexual and social behaviours; therefore it is important for detecting pheromones, or body scents. It is thought that this organ helps dogs to recognize people and other dogs.

The wetness of a dog’s nose is for an important reason – it dissolves molecules in the air and allows them to communicate with the olfactory receptors. The sniffing action actually enhances the ability to detect scents. When the dog inhales, the inhaled air is forced into nasal pockets formed by the nasal bones. Upon exhalation, this air remains and the end result is that the scent molecules accumulate and can interact with the olfactory receptors to form a distinguishable odour that is interpreted by the brain. Therefore, the dog is able to pick up and follow a scent trail!

The ability to pick up on certain odours and follow a trail becomes very useful in society. Dogs are used at airports to detect the illegal importation of drugs and agriculture products. Law enforcement agencies use the dog’s olfactory ability for tracking lost or missing people and forensic cadaver materials. Recently, studies have claimed that dogs can detect specific types of tumours in humans. Certain dog breeds are preferred for this type of work because they have been bred for hundreds of years for this specific task. This includes Beagles, Labrador and Golden Retrievers, the Belgian Malinois and German Shepherds. However, your dog does not need to be any of these specific breeds to have some fun with tracking! Many dog owners with a wide variety of breeds participate in the sport of tracking. This involves a predetermined track laid out that may include turns and corners with articles such as gloves randomly distributed. The dog’s goal is to follow the track and to indicate that an article has been found. The indicator is usually an action such as lying down. Dogs may earn tracking titles through the Canadian Kennel Club or American Kennel Club, so they must be registered with these clubs. But even if your dog is not, you can still participate in tracking for fun. There are many great introductory books out there or even better, find out if there is a local tracking club in your area where you can learn the basics and get one-on-one help. Happy tracking!

By Amanda Low – writer

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