Welcome to brain Stuff from how Stuff Works, Hey, brain Stuff, Lauren vog Obam here. If you've ever shared a home with a dog, you've probably had the startling experience of, while minding your own business, having a cold, wet nose thrust into your skin like a friendly ice cube. It's your pup's way of getting your attention, and it's an old wives tale that's such a wet nose is a good thing because it supposedly means your dog is in
good health. But this idea has no basis. In fact, whether a dog has a wet nose is not a signal one way or another of health. But why are dogs noses sometimes dry and sometimes wet. The short answer is that dogs sometimes lick their noses, But the catch is that no one knows for sure why they do that. One theory suggests that because dogs are always licking their noses, their saliva helps paint their schnas with the mucus produced in the nostrils. As a result, all that mucus looking
improves a dog's ability to smell things. Let's break down how that works. When dogs sniff the air, and they are always sniffing the air, they inhale tiny suspended particles. These particles get trapped in their nasal mucus, which helps the dog figure out what they're smelling. As a dog licks its nose, it picks up some of these scent Latin goop. The tongue then brushes against an olfactory gland on the roof of the mouth, which helps our four
legged companions figure out exactly what they're smelling. Another reason some have suggested could be that a wet nose helps keep a dog cool in warm weather. When we humans sweat, the perspiration are sweat glands produce evaporates off of our skin, cooling us down. Dogs, however, do not sweat. That's because they have no sweat glands except from the bottom of their pop haads. Instead, they pant to cool off. However, a dog's nose, unlike the rest of its body, is
not covered in fur. It also brims with blood vessels. When a dog licks its nose, the theory suggests it's cooling itself down as it's saliva like human sweat, evaporates that leaves the surface area of the no cool along with the blood circulating in and around Fido's snout. Consequently, cooler blood flows the dog's head and body, keeping our best friends a little bit cooler. But then, why are dogs noses often dry? A few factors can lead to
less licking. Touch your dog's nose in the morning, chances are it'll be dries the sahara. That's because as a dog sleeps, it rarely licks its nose, and certain breeds like bulldogs and pugs, have noses that are mostly dry. Age also tends to make a dog nose dryer. The bottom line is that if your dog has a dry nose, chill out. The dog isn't sick. Wait a few hours and it will be wet again. Oh and a bonus pup nose fact. Have you noticed that your dog has
slits on the sides of its nose. There's a reason when dogs exhale, they do so out of those slits. That's so that the exhaled air does not mix with the scented inhaled air, which flows into the nostrils. Today's episode was written by John Paritano and produced by Tyler Clang. For more in this and lots of other startling topics, visit our home planet, how Stuff Works dot Com.