Dogs are known for their keen sense of smell. But scientists have discovered their noses also have the ability to detect weak thermal radiation.
Around the world, dogs are celebrated for their ability to sniff out everything from cancer to meteorites. But the capabilities of canine noses don’t end with their sense of smell. A team of scientists at Lund University (Sweden) and Eötvös Loránd University (Hungary), recently conducted a study to test their hypothesis that dogs’ noses are particularly sensitive to radiating heat – and the findings are fascinating!
As far as we know, only a few animals can sense this type of heat, including black fire beetles, vampire bats, and certain species of snake. In most cases, this unique skill is used to hunt prey – which may explain why dogs also have the ability. The researchers suspect our canine companions inherited it from their gray wolf cousins, who likely use their noses to help them find warm bodies when hunting for food.
Like other mammals able to detect heat, dogs have smooth, naked skin (called the rhinarium) on the tips of their noses. This skin is moist, cold, and covered in nerves, which is why the research team proposed that dogs might be able to detect radiating heat. To test their theory, they trained three dogs to choose between a warm (88°F or 31°C) and ambient-temperature object, each placed 5.25’ (1.6m) away. The dogs weren’t able to see or smell the difference between these objects, but after training they were all able to detect the object emitting weak thermal radiation.
The team then used functional magnetic resonance imaging to look at the brains of 13 different dogs as they sniffed two objects: one neutral and one warm. They discovered that a region in the left somatosensory cortex – the part of the nervous system connected to senses such as temperature and smell – was more responsive to the warm object.
It remains unknown whether dogs can detect heat from a farther distance, but the researchers hope their findings will lead to further study. “The canine heat sense has been overlooked for thousands of years,” says principal investigator, Ronald H. H. Kröger. “It is possible that other carnivorans possess a similar infrared sense, and that adds a new chapter to the story of prey-predator relationships. We hope further studies investigating the details of this newly discovered sense will receive much professional and public interest.”