Researcher Anna Belin of Iotovs Lorand University in Budapest, Hungary studied the behavior of animals. She says that when a dog sleeps, their nostrils are usually hot and dry. When dogs wake up, they lick their noses and go back when they are cold and wet. Researchers wanted to know if there is any benefit to a dog having a cold nose.
One hypothesis was that a cold nose may help the dog regulate body temperature, but the tip is so small that it is unlikely to contribute meaningfully to thermal regulation. The research team measured the nasal temperature of several animals, including the nose of horses, dogs and moose. The team determined that the tips of the nose of dogs and carnivorous animals are generally colder than those of vegetarians.
The next step was to find out if a cooler nose gave advantage to carnivorous animals in the wild. The team conducted experiments looking at the behavior and brain to see if a cold nose was created to detect better heat. The team successfully trained three dogs to choose a warmer object that was about the same temperature as a potential victim of an object at room temperature.
Indicated dogs can detect weak thermal radiation from afar when they are prey. In a second brain-focused investigation, scientists presented a box containing hot water and an insulating door to 13 dogs, trained to lie still in a working MRI scanner. Dogs had a higher response when opening doors, revealing a warmer surface than when doors were closed, and when the surface was cold.
In particular, the left hemisphere of the brain was ignited in these tests, the side that processes food responses and is associated with predator activity in many vertebrates. Researchers believe that dogs and other cold-nosed animals may use heat detection senses with other senses when going on a hunt.