Jack London 
The Call of the Wild [EPUB ebook] 

The Call of the Wild is a novel by American writer Jack London. The plot concerns a previously domesticated and even somewhat pampered dog named Buck, whose primordial instincts return after a series of events finds him serving as a sled dog in the treacherous, frigid Yukon during the days of the 19th century Klondike Gold Rushes.
This book is one of London's most-read books, and it is generally considered one of his best. Because the protagonist is a dog, it is sometimes classified as a juvenile novel, suitable for children, but it is dark in tone and contains numerous scenes of cruelty and violence.