How far down can a dog smell

Knowledge pool
totally phenomenal - senses


How can a large German shepherd recognize a tiny Yorckshire terrier that looks a lot more like guinea pigs than dogs than fellow dogs? He recognizes him as a dog with his nose. Dogs can distinguish far more odors than humans and recognize a scent even at the smallest concentrations. Against them, humans appear almost "odor-blind".

  • Trained dogs can smell so good that they can even sniff out hidden and wrapped drugs
  • Inside the nose of micro and macrosomats

Good nose

It is not for nothing that dogs and other particularly fragrance-sensitive animals such as foxes or deer have long snouts.

In this snout space, the nasal bones are folded up to form the "Turbinalia", which have a large surface for them Olfactory mucous membranes Offer. With 220 million olfactory cells, dogs have ten times more than humans.

Such animals, endowed with extremely good olfactory abilities, are called "Macrosmata". Most mammals belong to this group, but humans do not belong to the group "Microsmats" is expected.

Dogs not only have many more olfactory cells, their cells are also more sensitive than those of humans. And finally, dogs have even better introductory techniques. In order not to tire the olfactory cells, they breathe intermittently. With their many short breaths, they succeed in smelling much better than a human: The dog can distinguish an estimated one million different smells, the human "only" 10,000.

Humans have been using this ability of the dog for their own purposes for thousands of years. Dogs help them herd the cattle, guard the house and hunt prey. But dogs are also used for much more specialized tasks because of their super noses. Dogs are trained to find victims under avalanches or rubble, to track down drugs, to find mines in minefields. Even some cancers can be detected by specially trained dogs based on the changed smell of body fluids.

Smell samples from suspects

A particularly macabre way of using the olfactory sense of dogs took place under the regime of the GDR: odor samples were collected from suspicious persons, for example by placing them on a special pillow during interrogation, which was then kept airtight and thus carried out possible persecution Dogs made possible.


The rodents belong to the mammals with particularly good olfactory abilities: mice, rats and hamsters. People take advantage of this to lure them into a trap with fragrant bacon or the like. But the rodents' sense of smell is not only used to find food or to recognize enemies, but also causes real family planning ...

  • mouse


If a young female mouse lives in the company of other sexually mature females, its own sexual maturity can be delayed. How can it come to that?

Researchers were able to prove that female mice by Pheromonesthat they excrete in the urine send an olfactory message. This prevents sex hormones from being released in other females. The young female does not become sexually mature at the same time as the dominant female mice.

It is the other way around in the company of males: The pheromones in the urine of a male cause a female mouse to become sexually mature even earlier than usual! And it gets even more astonishing: This only works if the male is not related to the young female! Scent messages from other mice interfere with the physical development of an animal, or to put it another way: the pheromones of conspecifics control the production of hormones in a mouse. In addition, the pheromone scents must be very finely differentiated, the scents of related animals have a different effect than the scents of unrelated animals.

In the mice, too, the chemical signal that the other mice send goes through them "Pheromone nose". This sends its message to the brain, which sends its message to the pituitary gland, which sends its message to the sex organs, which then grow to sexual maturity.

  • Rats have an excellent sense of smell


In terms of smell, rats are clever little creatures. Indian scientists have found that these rodents have the ability of stereo smelling. This literally means that you perceive smells spatially: you can distinguish exactly whether a smell comes from the left or from the right by determining whether the smell first reaches one nostril or the other. It is assumed that other mammals can also smell spatially. But it has not yet been proven.

  • Syrian golden hamster


Syrian golden hamster live alone and don't want to know anything about each other. With one exception: when mating. So that the male is not constantly annoying, comes to visit unwanted and then has to go without having achieved anything, the female will let him know when the time comes. It lays a scent trail in its burrow, similar to a scavenger hunt.

The male follows this trail into the burrow. The same thing always happens obsessively here. The female shows her willingness to mate with a rigid posture. The male sniffs the female hamster on the cheek gland, then on the flanks and finally in the genital area. The vaginal secretion of the female contains a certain sexual pheromone, the Aphrodisin. If the male inhales this molecule with the air, the aphrodisin gets into the Pheromone nose of the male. Now it knows: it can (it must!) Mate with the female.

© Text: Evelyn Bargs-Stahl, Dr. Erika Luck-Haller