Having gained a measure of TV fame by 1958, the nightclub comedy duo of Dan Rowan and Dick Martin decided to give movies a try with Once Upon a Horse. Dan and Dick play Dan Casey and Doc Logan, a pair of nitwitted cowboys who turn to outlawry because they can't make a go at any honest profession. Stealing a valuable herd of cattle, the boys' dreams of financial security are dashed when they're forced to raise money to feed their stolen bovines. Martha Hyer costars as Miss Amity Babb, a resourceful saloon hall owner who applies 20th century business methods to her 19th century operation. For nostalgia buffs, several western-movie favorites (billed as "Our Old Pals") make cameo appearances, including Tom Keene, Bob Livingston, Kermit Maynard and Bob Steele. Hal Kanter's screenplay is full of clever, satirical touches, most of which proved to be too smart for the room in 1958. A financial disappointment, Once Upon a Horse (aka Hot Horse) would be Rowan and Martin's last joint film effort until 1969's The Maltese Bippy.