The Call of the Wild
Jack London, 1903.
Before you read: Dogs are hurt and killed. The book is violent. Older readers only.
Buck, a comfortable California dog, is stolen and sold into the Klondike as a sled dog. He learns a harsh pack order, a driver who is decent, and drivers who are not. London writes the north as a place that strips away anything extra. Buck becomes less a pet and more a wild animal. The book is famous, short, and not gentle. It is an adventure about strength and also a record of cruelty to animals that a reader should not cheer for.
Public-domain text.