Getting greeted at the door by a wagging tail is one of the purest pleasures of owning a pooch. No matter how big, small, or fluffy your dog’s tail is, they will move it around, often at great speed!

As any dog owner knows, there are a few surefire ways to cue a pup’s wagging tail: arriving home from work, picking up their favorite toy or uttering the word “outside.” But why do dogs wag their tail ...