Researchers reveal new sense in dogs
“It has taken a long time for humans to discover this given that humans and dogs began living side by side on earth 15 000 years ago, and for that whole time we have been unaware of this ability in dogs”, says Ronald Kröger, professor at Lund University.
The research team has obtained the results in two different experiments. In behavioural experiments in Lund, they concluded that dogs, at a distance of 1.6 metres, prefer a small, body-temperature surface to a same-sized cold surface. In Budapest, the researchers have studied the brain activity in dogs with magnetic resonance imaging. When exposed to weak heat stimuli, the part of the brain that processes sensory information from the skin was activated, most likely from the naked skin on the dog’s nose where the skin structure is called the rhinarium.
According to the researchers, the study is another piece of the puzzle that explains why certain predators, for example wolves, are skilled hunters. In addition to smell, sight and hearing, it is likely that they can use their cold noses to identify the body heat of prey from a distance. On the other hand, prey are vulnerable if they radiate too much heat, which the researchers say could be an explanation for lambs having thick wool.
In addition, the study provides guidance on which dog breeds should be chosen for hunting and for search and rescue operations, for example in avalanches or earthquakes.
“The dog’s nose has to be cold to be able to detect a warm human body. Our results make it easy to exclude breeds that are not able to cool their noses down due to intense breeding. Hunting training also becomes more effective if you not only train with objects that smell but also those that radiate heat”, says Ronald Kröger.
The dogs that participated in the study have been trained on weak heat radiation. The first was Ronald Kröger’s own golden retriever, Kevin, who has participated since the start in 2012. In the training, the researchers have always used a rewards system, never punishments.