Animal IQ

Dogs Are Great Sniffers Because They Have A Second "Nose"

You may have two nostrils, but you surely only have one nose. Dogs are a slightly different story. Behind the big, wet pooch nose we all know and love is another organ that boosts sniff power. It's called Jacobson's organ, and you don't have one. If you did, you may be able to use it to detect cancer.

Do You Smell That?

It's no mystery that dogs have the gift of sniff. (We might not actually be too far behind a dog's sense of smell, but that's a different story.) Dogs have something of a second "nose" called the vomeronasal organ (VNO), or the Jacobson's organ. This second smelling device sits at the back of a dog's nasal passage, on the ready to detect pheromones and other compounds. This is a kind of accessory olfactory bulb with completely different neurons than the ones associated with the sense of smell, anthrozoologist John Bradshaw tells Slate.

Turns out, a lot of animals still have this. If you love Googling funny animal faces as much as we so, you've probably seen evidence of the VNO in action. The flehmen response is basically a fancy word for goofy lip-curl animal face. By peeling their lips back, animals with a Jacobson's organ are exposing two ducts (the nasopalatine canals) on the roofs of their mouths that connect to the VNO. Humans may have once had the VNO, but it's almost definitely not functional today. Too bad, we're so curious to know what our flehmen face would look like...

Hello, Dr. Dog

If dogs aren't the only ones with this special organ, what makes them so special? They can use it to detect cancer. To be fair, other animals have successfully detected cancer too. Like pigeons and fruit flies. But check out this impressive resume: In studies, dogs were shown to detect melanoma tissue in skin samples, bladder cancer and prostate cancer in urine samples, lung and breast cancer in breath samples, ovarian carcinoma in tissue and blood samples, and colorectal cancer in breath and stool samples. What they're really detecting are odors the cancer produces, called volatile organic compounds. However, the dogs that boast these achievements underwent very expensive training that took a long time. While it's a promising skill, labs likely won't be flooded with labradors any time soon.

Key Facts In This Video

  1. In 2008, a dog named Max seemed to detect cancer in his owner. 00:31

  2. Dogs have the ability to smell the volatile chemicals released by cancerous tumors. 02:51

  3. Dogs can sense when a person's blood sugar levels are low. 03:18

Written by Curiosity Staff July 22, 2017

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