According to a review summary in the New York Times, Joe E. Brown was affectionately pawed by a lion during one take, requiring 6 stitches in his arm. The article also points out that Brown did his own "spectacular acrobatics" - no doubles were used.
A few cast members in studio records/casting call lists for this movie were not seen in the final print. These were (with their character names, if any): Bobby Caldwell (Happy as a Boy), William Demarest (Ringmaster), and William B. Davidson. Tom Dugan was also not seen in the print, but he was credited in position 11 as "Mac."
Keep an eye out for Ward Bond as the straw hat-wearing "Unimpressed Man" (uncredited) next to Pop in the final circus scene.
Gracie Hanneford's debut.