Jack London 
The Call of the Wild [EPUB ebook] 

The plot concerns a previously domesticated dog named Buck, whose primordial instincts return after a series of events leads to his serving as a sled dog in the Yukon. Buck learns from his experiences and becomes a pack-dominating feral beast. He learns lessons and relies on resurgent behaviors inherited from his wild predecessors, helping him to survive adversity as a ferocious animal.