How dogs smell

The dog nose is truly a masterpiece of nature. The sense of smell is their most important sense organ to find their way in their environment. A dog nose is not only capable of absorbing odours, it is also used for humidifying, heating and above all, cleaning the inhaled air. Furthermore, man’s best friend is not only a master at tracking down food, their sniffer will also easily find a suitable sex partner, but also be warned of rivals or imminent danger in good time.  

The papillae of the nose are similar to the human fingerprint, unique.

It is assumed that our four-legged pets can smell up to 1 Mio. times better than humans. I would like to illustrate what this means with this example: Imagine a soccer field filled with sand. Our super noses are able to sniff out a single grain of sand. They also smell the individual components (e.g. not chocolate cake, but cocoa, milk, flour, eggs, …). Fascinating, isn’t it? It is also no wonder why we use dogs as true sniffers in the police, in disaster control or in medicine.  

Which dogs smell the best?

In general, the longer the snout of a dog, the better the sense of smell. A German shepherd has a clear advantage if you compare his olfactory performance with that of a pug. Depending on the size, breed and length of the muzzle, the dog nose is equipped with up to 210 million olfactory cells (humans approx. 5 million). This makes up about 8 square meters of olfactory mucosa, humans have only 0.5 square meters. As you can see, we humans suck quite a bit.  Brachiocephalous (short snout) dog breeds are clearly at a disadvantage because they simply lack the space for larger nasal conches. The larger the nasal conch, the larger the surface area for receiving the incoming scent molecules.   

How does a dog nose work?

The scent molecules contained in the air are absorbed via the nostrils and transported further into the nasal cavity and its so-called nasal concha. There they meet the olfactory mucosa, which is equipped with immensely many ciliated hairs and nerve cells (ciliated epithelium). Even weak scent molecules are extremely amplified there. The information is then sent via the olfactory nerve to the brain, where the odours are processed. The area of the brain that is responsible for smelling is about 10% in a dog, but only 1% in humans. The inhaled air also lingers longer in the dog’s nose, in humans the air is transported directly into the lungs. Once a dog has picked up a trail, it can take up to 300 breaths per minute. Another advantage over humans is that dogs can use their nostrils separately (stereo) and thus better locate the direction of an odour.  

Further interesting dog nose facts

• The Jacobson’s organ is located between the nostril and the palate. This small “channel” also contains olfactory cells, which are directly connected to the olfactory brain and the limbic system (processing of emotions, release of endorphins). This enables dogs to smell (human) emotions by releasing various pheromones in humans and other dogs. This enables them to filter out detailed information about other dogs. For example, whether the dog that peed here was healthy or whether the bitch was in heat. If you have a male dog, you know the detailed smacking and rattling for sure.
• Through glands in the dog’s nose, the nose is always kept moist to better absorb the scent molecules.
• Nasal work makes thirsty, as the nasal mucous membrane dries out during rapid sniffing.
• Dogs can smell possible epileptic seizures in humans, cancer cells, diabetes and many other diseases. Through targeted training they warn us and support us in everyday life with an illness.
• Female Dogs usually have a more pronounced sense of smell than males and darker coloured breeds are also somewhat superior to lighter ones.
• Dogs have a clear idea of what they smell. When they pick up a trail, they “see” in their mind’s eye what awaits them at the end of the trail.  
• The vegetative (unconscious) nervous system is closely connected with the sense of smell. Therefore, smells influence emotions and vice versa.
• The sense of smell reaches about 3 meters under the ground. So any mouse can easily be tracked down.