There's a powerful weapon out there. It can sense fear, perceive your mood and differentiate between your 'happy' and 'sad' tears. It can predict natural disasters; bust you for drug possession; rescue you if you are lost or trapped under rubble; protect you from a gas explosion; be instrumental in solving a murder case; and even detect if you have cancer.
Woe unto you if you've been 'unfaithful' with another animal because this is one lie-detector test that cannot be fooled. Best of all, it cannot be created by man. Guessed yet? ...Wet and cold, it's the canine nose. Everything about the dog's nose is designed to maximise the capture and analysis of odours, making it one of nature's wonders and ensuring that smell is the dominant sense a dog possesses.
Let's start with the dog's ability to detect scents. His nostrils act like antennae and he can wiggle his nose to best determine the direction from which the air currents are flowing.Sniffing–a string of quick inhales and exhales–helps a dog to rapidly identify a scent. Each deliberate sniff widens the dog's nostrils, allowing him to pull in more scent-laden air. A sniff also temporarily straightens the dog's nasal cavity, allowing odour molecules to proceed directly to receptors deeper in the nose. Ever wondered why your dog's nose is always cold to the touch? The moist, chilly leathery surface of the snout acts like Velcro, catching even the tiniest molecules of smells and dissolving them so that the dog's internal receptor cells can analyse them properly.
To keep his nose wet, a dog must produce a constant supply of mucus through his nasal cavity. It is a common misconception that a warm nose is an indicator of a fever in a dog–a hot nose simply means a high surface temperature, which varies with the environment and blood vessels near the skin's surface. Once the air is inside the dog's nose, it passes over bony scroll-shaped plates called turbinates. These are covered with a thick, spongy membrane that contains most of the scent-detecting cells, as well as the nerves that transmit information to the brain. The dog's scent-detecting ability can vary even from breed to breed. A Dachshund has 125 million scent receptors, while a German shepherd has 225 million, and a Bloodhound tops the chart at 300 million receptors.
A dog's brain is also specialised for analysing and identifying scents. Dogs have two giant olfactory bulbs attached to the brain which decode every smell they encounter. The bulbs weigh around 60 grammes, four times as much as human olfactory bulbs. A canine brain is one tenth of the size of a human brain, which means that this 'smell centre' in a dog is 40 times larger than that of a human.
As if this weren't enough, a dog also has a Jacobson's organ, a special chamber above the roof of his mouth, which has its own scent receptors. This organ transmits nerve impulses to the brain's hypothalamus, an area associated with social and mating behaviour.
Now that you have an improved knowledge into the workings of your dog's nose, hopefully you have gained a better understanding as to why your dog tenses up before a thunderstorm (he can smell the change in electrical charges in the air currents); how he can warn a patient before an epileptic fit or seizure attack; why he sniffs the butts of other dogs (tells him the age, sex, reproductive status of the other); how he can save your life by detecting gas leaks and termite infestations up to 40 feet underground; why he raids the garbage and rolls around in carcasses right after you've bathed him; and why he pokes his nose into your groin when greeting you ... he's not being rude, you just happen to have scent glands there!
Trivia tip: Your canine's nose has a pattern of ridges and dimples and a unique nostril outline which form a 'nose print' that is as individual to your dog as your fingerprint is to you!
The information contained in this document is the copyrighted property of Best Pets Animal Behaviour Service.