Your Dog's Super Sniffer

Dogs are renowned for their sense of smell. Estimates on how much better their olfactory system works than ours range from hundreds to as much as one million times as good. That’s because one third of the canine brain is devoted to olfaction and dogs have very sensitive detectors inside their noses for picking up scents.

Canine noses are so sensitive that no mechanical sniffing device exists that can even approach their precision. So it’s only natural that dogs are used for all types of jobs, from rescuing trapped people to drug surveillance to searching for cadavers.

The source of this incredible ability is a nasal cavity rich with blood vessels and nerve endings that connect to a highly developed olfactory center in the brain.

Dogs have many more sensory 'smelling' cells than a man's 5,000,000.

A Dachshund, for example has 125,000,000; a Fox Terrier has 147,000,000 and a German Shepherd (often used as a 'sniffer' dog) has 220,000,000.

Truffle hounds can find the fungus delicacy even when it's a foot underground!

However, a dog's nose is not just used for smelling, but also to keep him cool. That's why a dog pants. The longer the dog's nose, the better his cooling system works.

Dogs can detect even lightest environmental changes, a distant object, also even changes in hormonal levels around them. They can sense signals many other things around unnoticed by humans through their noses.

Dogs can distinguish two different types of scents when trailing, an air scent from some person or thing that has recently passed by, as well as a ground scent that remains detectable for a much longer period.

Dogs sometimes display a behavior that researchers call "scanning." They lower their noses to the ground near the scent and then move horizontally toward it, pausing when they are directly above it. Then they scan past the source, and finally return to it. Presumably this allows them to see what they are sniffing before they get there and to get a sense of how the scent is distributed.


Dogs experience the world nose-first. Even though dogs introduce themselves by sniffing each others faces, it's the back ends that get the most attention. A quick sniff reveals a lot: how old a dog is, which sex, neutered or intact, relative or stranger.

Scents also reveal a dog's confidence and social status, and what his mood happens to be at the moment. Dogs synthesize all of this information and figure out very quickly what their relationship with another dog is likely to be.

Your dog knows your scent and has it filed in his memory, along with the smells of all the other people he's been introduced to. Some people your dog will remember with affection, others with fear and loathing -- and his "scent memory" will be triggered every time he meets them.

And like it or not, your dog can tell a lot about your mood just by your smell. A person's body odor is believed to change depending on his or her mood, and dogs are thought to be able to pick up on this.


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