Tarka the Otter — Henry Williamson

First published in 1927, now public domain in the US.
There is no safety in nature. Tarka, an otter cub, grows up with his mother and sisters, learning how to swim and catch fish as well as how to be afraid of the cries of hunters and the flash of metal traps. Gradually, he will have to travel alone, occasionally with the female otters White-tip and Greymuzzle, who are always evading capture. They will journey through rivers, woods, moors, ponds, and out to sea. He eventually encounters his adversary, the terrifying dog Deadlock, while being pursued by a pack of hounds and is forced to battle for his life.