Shadow by Michael Morpurgo

The bravest dog in all the world!

This is the story of Aman, a boy from Afghanistan fleeing the horror of the Afghan war.

When a western dog shows up outside the caves where Aman lives with his mother, Aman is initially repulsed -- it is not customary for people to keep dogs as pets in his part of the world.

But when Aman and his mother finally decide to make a bid for freedom, the dog Aman has called Shadow will not leave their side. Soon it becomes clear: the destinies of boy and dog are linked, and always will be!