A little known gem from the Fifties called "Goodbye To My Lady".
If you ever see it on a TV schedule, dvd catalogue, or in a dvd store, JUMP ON IT!
Its both good, and hard to find.
But also be sure to have a box or two of kleenexes at your side.
A lonely young boy growing up in bayou country without parents, and being raised by his granddad played by Walter Brennan, finds a strange looking dog in the coastal marshes. They bond, hunt together, etc.
Some time later news reaches thier small town that the dog is a rare expensive ancient breed ( a besenji-this film was made fifty years before basenji dogs were cool) owned by a rich family passing through. So the boy is faced with a moral choice: return the dog to its rightful owner, or keep his canine campanion.
I'm sorry... I need to find some kleenexes right now...