It's easy to see why dogs are the most popular pets in the world. For a run in the park or a cozy snuggle on the couch, a dog is the perfect companion! But dogs are much more than just loyal pets. For thousands of years, these amazing animals have helped people herd sheep, hunt for food, and keep warm.

Award-winning science writer Seymour Simon has teamed up with the Smithsonian Institution to bring you an updated edition of his classic full-color photographic introduction to man's best friend.