Once Upon a Time, There Lived a Dog(1982)

Original title: Жил-был пёс

Based on the Ukrainian folktale, the old dog of a village family is not as keen as he once was, and is sent away after he fails to guard their house during a robbery. In the woods, he meets the wolf he protected his masters against long ago, who decides to pay a favor to get his old enemy's rightful place back in the doghouse.