Continuity mistake: In the beginning when Topper is about to fight, he puts a red bandana around his head. As he is walking to the fight, one of the flaps of the bandana is draped over his shoulder. The shot changes when he gets to the fight, and both flaps are now behind his shoulders.
Continuity mistake: When Topper is trying to get the keys to free the colonel, he knocks the pepper-shaker over, but there's no visible concentration of pepper. After the colonel gets the keys, a mouse is shown on the table. It goes up to the newspaper and sneezes from the mound of pepper which was not there before.