"The Call of The Wild" - Jack London

In this novel the main protagonist, Buck, a St. Bernard/Collie mix, is abducted by a member of his original owner's household. Sold to a trainer of sled dogs in Alaska in order to pay off a dept, he adapts to the brutal conditions and is eventually acquired by a loving man. When this new owner is killed, Buck follows the ‘call of the wild’ and joins a pack of wolves.