It’s been said that human would go absolutely insane if we had as many smell receptors in our noses as dogs – it’d be sensory overload. But dogs depend on their noses as much as we depend on our vision, which is why canines have more than 100 million sensory receptor sites in their nasal cavities. Humans? We only have 6 million. More importantly, perhaps, is that dogs’ brains have about 40 times more space devoted to analyzing odors than human brains.
Under perfect conditions, dogs can pick up specific scents from 12 miles away. So, when you stash their favorite treat high up, tucked away in the cupboard and your pup sits eyes and nose pointed in the direction of the treat, you can bet they’re keen sense of smell knows exactly where you put it.
Here’s a list of things dogs can smell that humans can’t:
- Epilepsy | Dogs can warn of an oncoming epilepsy attack
- Ovulation | Cattle farmers use trained dogs to smell the urine cows they want to breed
- Bed bugs | Getting bit at night? Dogs can detect bed bugs with 96% accuracy
- Cancer | With accuracy rate between 88 and 97%, dogs save lives through early detection
- Emotions | Dogs pick up on stress hormones, such as cortisol and adrenaline, so they can detect when you’re sad or distressed
- Heat | Dogs have something akin to infrared detectors in their noses, which pick up on the slightest heat signatures
- Drugs | Smugglers try to hide their stash in coffee and various other substances, but dogs aren’t thrown off
- Diabetes | Diabetics are victims of high glucose levels, which dogs can detect on human breath
- Explosives | With the right training, dogs can pick up on even the slightest scent of explosives
Born to Sniff
Canines have a rather complex and sophisticated olfactory system, which is why your dog seemingly obsessively sniffs everything it possibly can while you’re on a walk. When your dog takes a whiff of something, individual smells are absorbed into separate chambers in their olfactory recess, which is how they can so cleverly pick up on scents humans can’t possibly detect.
When walking your dog, it’s extremely important to let them stop along the way and sniff out their surroundings. They are essentially investigating the world with their nose, picking up information and processing it. Some canine experts refer to these walks as “scent walks.” Rather than logging in miles, they’re logging scents, which is why dog owners shouldn’t be so consumed about a destination or the number of steps taken – rather, they should be open to wandering aimlessly and letting the nose be the guide.
Scent Walk Benefits
While it’s true that dogs need to run off excess energy, which can lessen the destructive behaviors at home, such as tearing a couch apart or excessive barking, dogs also need to work their noses. Dogs that are go on scent walks are also much less apt to display destructive behaviors at home.
It's understandable that when a pet owner needs to get a jog in and can’t stop to smell the roses, the canine jogging companion will have to settle for exercising the muscles instead of the nose. However, Dr. Alexandra Horowitz, who has been widely cited for extolling the benefits of scent walks, says it’s important to make time scent walk. She said in a New York Times interview that “there’s a pleasure for owners in letting a dog be a dog, to acknowledge their dogness. They put up with a lot of our humanness.”