Bosko runs a hot dog stand at an amusement park. He sells a hot dog to a bow-wow-type dog; but before the dog can eat it, the hot dog cries out, "Mammy!" in imitation of Al Jolson. The dog happily replies, "Sonny boy!" The dog and hot dog kiss and go off skipping and barking, joyfully reunited. Meanwhile, Bosko sneaks away from his hot dog stand so that he can compete as a jockey at a nearby racetrack. Bosko's horse is only mechanical; but his pluck and quick-thinking will give him an edge over his competition.