Jack London 
Oxford Children’s Classics: The Call of the Wild [PDF ebook] 

This Oxford Children’s Classic features an introduction by Anthony Mc Gowan and other bonus material including insights for readers, facts, activities, and more . . .Half St Bernard and half sheepdog, Buck is stolen away from his comfortable life as a pet and put to work as a sled dog in Alaska. Surrounded by cruelty, he adapts and learns the ways of the wilderness. Using his strength and instinct, Buck must fight for survival.