Man’s best friend is famous for its sense of smell. In canines this consists of a nasal vestibule and olfactory epithelium. The former channels odour-rich particles to the latter, with the epithelium supporting millions of receptor cells that absorb the odour’s chemical composition patterns and then transports them to the brain for interpretation. Indeed, an average dog’s nose has so many olfactory receptors that its sense of smell is 1,000 times more acute than ours. And why are dog noses wet? Well, they generally have damp snouts for two reasons. Firstly, a wet nose is better for smelling. The moisture comes from a layer of mucous that thinly covers the surface, trapping and soaking up scent particles. The dog can therefore naturally sniff in the smell as it radiates off the nose, or lick it to taste the odour. The second reason is that it is one of the few parts of the body where dogs can excrete sweat.