It’s a kind of “new meaning” discovered in the noses of dogs by a research team at the University of Colorado at Boulder. It is a “fascinating discovery”, as ethologist Marc Bekoff, a canine sniffing expert not involved in the study, describes it.
According to the researchers, in fact, dogs with their noses can not only sniff but also perceive mammalian body heat levels without a direct touch and therefore at a certain distance.
This is not a unique ability in absolute: that of perceiving radiant heat from living beings is a characteristic also present in some beetles, in some species of snakes and in a mammal species, the vampire bat.
Researchers have in fact discovered that the rhinaria of dogs, the naked and smooth area on the tip of the nose around the nostrils, is humid, colder than room temperature and very rich in nerves.
Precisely on the basis of these characteristics, the researchers immediately thought that dogs’ noses could not only detect the sense of smell but also heat. In order to obtain confirmation, they performed experiments on three pet dogs who had to choose a particular warm object and one at room temperature. The researchers positioned the objects at a distance of 1.6 metres.
All three dogs detected the objects emitting heat radiation with a certain level of success.
At this point, the researchers scanned the brains of other dogs of various breeds using functional MRI scans when they presented the dogs with objects that emit heat radiation or objects that did not.
Dogs were much more sensitive to hot thermal stimulation than neutral objects that did not emit any reaction.
These experiments therefore confirm that dogs can perceive heat through the nose, something that probably triggers a particular region of the brain. The dogs themselves probably inherited this ability from their direct ancestor, the grey wolf, who can sniff out hot bodies during hunting.
The study was published in Scientific Reports.