Lad: A Dog is a 1919 novel written by Albert Payson Terhune, loosely based on the life of Terhune's real-life rough collie, Lad. Born in 1902, the real-life Lad was an unregistered collie of unknown lineage. Through Lad's adventures, Terhune expresses his views on parenting, obtaining perfect obedience without force, and the nature and rights of the "well-bred." It has sold more than one million copies and remains Terhune's best-selling work.