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The surface of a dog's nose contains a pattern of ridges and grooves that can differ between individuals.
Historically, nose-print identification has even been used in some contexts as a method of distinguishing dogs, although modern identification systems such as microchips are far more practical and reliable.
The pattern isn't the same thing as a human fingerprint, but the comparison comes from its distinctive surface structure.
A feature used constantly for smelling also carries a surprisingly intricate physical pattern.
© American Kennel Club