The first species to be domesticated, dogs have been selectively bred over thousands of years. Today they're man's best friend--but while many are pets, many, too, are working animals: for the police, for the blind, as guard dogs, as sheepdogs, for pulling sleds, and as therapy animals. From huskies to German shepherds, from collies to Chihuahuas, Shih Tzu to Jack Russell Terriers, Labradors to Bullmastiffs to Dachshunds, this book includes a vast range of breeds. With fascinating captions on every page, even dog lovers will learn something new.