Donald Crisp may get the top billing, but it's the unnamed pooch who's the real star here. Bobby may belong to the farm, but he loves Alex Mackenzie, and when the old man is fired and heads to Edinburgh, the dog follows him. Alas, Mackenzie dies and is buried, but the dog walks with the poor cortege to Greyfriars graveyard and plops down on the grave, where grouchy Crisp doesn't want him, but kindly tavern keeper Laurence Naismith does. However, Kay Walsh, Crisp's wife, admires Bobby's rat-killing, and soon a competition arises between the two men for more than a decade, as the wee dog guards its master's grave.
Based on Eleanor Atkinson's sentimental 1912 novel (it had already been plundered for 1949's CHALLENGE TO LASSIE, also starring Crisp), it's pure Disney sentimentality placed on a well-decorated lot in Shepperton, as well as fine establishing shots in Edinburgh and the Scottish countryside.
Crisp may not deserve top billing, but he had certainly earned it. His movie career stretched back to 1908, when he became a member of D.W. Griffith stock company at the age of 26. When this movie came out, he was nearly 80. After one more movie, he retired and lived to be over 90.