All dog owners have had their pet crush their nose against their face or other parts of the body. Dog noses are often cold and slimy, but other times they are hot and dry. Most pet owners have at some point wondered whether their dog’s nose should be wet or dry. Researchers recently studied animal noses and determined that it’s normal for a dog’s nose to be cold and wet, but it’s also normal for a dog to have a hot, dry nose.
Researcher Anna Bálint of Eötvös Loránd University in Budapest, Hungary, studies animal behavior. He says that when a dog sleeps, his nose usually gets warm and dry. When dogs wake up, they lick their noses and become cold and wet again. The researchers wanted to know if there was a benefit to the dog̵
One hypothesis was that the cold nose could help the dog regulate body temperature, but the tip is so small that it is unlikely to contribute significantly to thermal regulation. The research team measured the temperature of many animal noses, including the noses of horses, dogs and moose. The team determined that the nose tips of carnivorous dogs and animals are typically colder than those of herbivores.
The next step was to figure out if a cooler nose offered carnivorous animals an advantage in the wild. The team conducted experiments examining behavior and the brain to see if a cold nose improved heat detection. The team successfully trained three dogs to choose a warmer object that was roughly the same temperature as the potential prey on an object at room temperature.
The results indicated that dogs can detect weak thermal radiation from a distance when hunting for prey. In the second brain-focused investigation, scientists presented a box containing hot water and an insulated door to 13 dogs trained to remain motionless in a working MRI scanner. The dogs’ brains had a higher response when the insulated doors opened, revealing the warmer surface than when the door was closed and the surface was cooler.
Specifically, in these tests, the left hemisphere of the brain is switched on, which is the side that tends to process responses to food and is linked to predatory activity in many vertebrates. Researchers believe that dogs and other cold-nosed animals could use heat sensing alongside other senses when out hunting.