A Dog's Nose Can Detect Thermal Heat, According to New Study
A new study suggests a dog's nose can detect thermal heat, in addition to smelling seizures and cancer.
You might have heard that a dog's nose is up to 100 million times more sensitive than our noses, which is why dogs can smell seizures before they start and can even smell cancer. But now, a new study published in the journal Scientific Reports suggests a dog's nose has another superpower: It can pick up on thermal heat.
That cold, moist, leathery tip at the end of a dog's nose that humans like to boop so much is called the rhinarium. Compared to other animals' noses, a dog's nose is usually a few degrees colder than the temperature of the environment it's in, which scientists have previously attributed to body temperature regulation. But the researchers involved in this new study hypothesized that dogs' cold noses may help them detect radiating weak heat—an ability that only a handful of animals, like vampire bats and black fire beetles, are known to have. That would help explain why dogs with impaired sight or hearing can still successfully hunt.
To test their theory, the researchers trained three pet dogs to choose between an object that was room temperature and one that was warmer than room temperature. The objects were placed about five feet away and covered so that the dogs couldn't see or smell them. In a series of double blind experiments, all three dogs were able to detect which of the objects emitted weak thermal radiation.
Next, they scanned the brains of 13 pet dogs while showing them objects that had either neutral radiation or weak thermal radiation, and found that the left somatosensory cortex—which delivers information from the nose to the brain—lit up in response to the warm stimuli. More incredible still, the radiation was so weak that the scientists had to touch the surfaces of the objects to see if they were warm, implying that a dog's nose is even more sensitive to thermal heat than human hands.
More research needs to be conducted to assess how this evolutionary trait developed, but it's yet another example that shows there's no shortage of amazing skills dogs have.