“Dogs noses are
specifically adapted to function much better than ours,” explains Michael T. Nappier, DVM, DABVP, of the Virginia Maryland College of Veterinary Medicine. “They have up to 300 million olfactory receptors in their noses, versus only about 6 million for us. And the part of their brain dedicated to interpreting these is about 40 times larger than ours.”
1. Short-Snouted Pups Are Less Smell Sensitive
Flat-faced and short-nosed dogs such as the pug, Pekinese, Chihuahua and boxer, have fewer scent-detecting receptor cells than dogs with longer snouts, such as a German Shepherd or bloodhound, which have 225 million and 300 million, respectively.
2. Dogs’ Noses Are Different From Ours
When humans inhale, we use the same air passage to both breathe and smell. Dogs’ noses, on the other hand, include a fold of tissue that separates the two functions.
Both human and dog noses contain bony turbinates, or plates, but inside a dog’s nose is a microscopically small, spongy membrane containing the scent cells. Like an accordion, if you could unfold all the crevices, the total surface may be as large as 60 square inches.1 No wonder they can smell so well!
Many dog breeds feature long, floppy ears to give them the unique talent of fanning aromas up into their nostrils, making their noses all the better to smell with.
4. Scent-Tracking Pups Are Persistent
Some dogs are enthusiastic about every one of the thousand things they catch a whiff of, say, on a walk in the woods or romp on the beach. But scent-tracking dogs zero in on specific targets and can walk right past a squirrel to find the source of the scent they’re focused on.
Bloodhounds have such scent-sensitive snoots that their excellent detection skills are helpful for purposes of law enforcement. They’ve even carried weight in court. Beagles are often chosen for sniffing duty by narcotics and U.S. Customs and Border Patrol agents.
German Shepherds are one breed used by police and the military for rescues and also drug detection. Dachshunds were bred to smell out badgers, and the Harrier was used to hunt rabbits (aka “hare”). Other notable noses belong to Basset Hounds, several Coonhound breeds and Labrador Retrievers.2
6. Some Dogs Trail, Others Track; Some Can Do Both
There’s a difference between dogs who can trail and others known for their tracking abilities, but many dogs are trained to do both, as one article describes:
“These dogs basically follow footsteps, they are orientated to a mixture of human scent and ground disturbance. They work on a long line and do not work from a scent article. They follow the freshest track.
(Trailing dogs) usually work from a scent article. They can work on or near the track to a good distance from the track depending on wind and environmental conditions, but they follow only the specified scent. They work on a long line and can work in wilderness, urban areas, buildings, in vegetation or on hard surfaces, (pavement).
7. Why are Dog Noses Wet?
Dogs have wet noses for different purposes. The primary reason they secrete mucous is to pick up smells better. Dogs also lick their noses quite often, which is their way of cleaning them when they’ve stuck their noses in their food or in the dirt. Dog noses are often wet because it helps them cool down.
In case you’ve heard that dogs with dry noses may not be feeling well, one dog expert says that’s not necessarily so. Dogs can be sick and still have a wet nose. Their proboscis moisture may just fluctuate with the weather or environment, or even the time of day.4
8. Dog Nose Prints Are Completely Unique
Like the fingerprints of humans, a dog’s nose print may be just as individualized. There are companies that register the nose prints of canines and store them in case the pet is lost or stolen, and kennels have begun a similar procedure. Canada has used this procedure to identify dogs for decades.5
Some breeds’ noses are more acute than others. Dogs can be trained to hone in on scents that often seem odd, extraordinary and even heroic. Just a few of those include dogs’ trained or innate ability to pick up the scent of explosives, drugs, missing persons, criminals on the run and strangers on your property.
The superior smelling capabilities of dogs — even yours — may give you a new respect for the incredible skills our canine companions possess.