Morgan, who owns a nearby race track, hotel and nightclub, holds the mortgage on the sanitarium and is attempting to foreclose on it in order to convert the building into a casino.

Tony, Judy's faithful employee, suggests asking financial help from the wealthy patient Mrs. Emily Upjohn, who is a hypochondriac, living at the sanitarium.

Tony contacts Hackenbush in Florida by telegram and when the Doctor arrives he immediately insults the Sanitarium's business manager Mr. Whitmore.

Meanwhile, Judy's beau, singer Gil Stewart, who performs at Morgan's nightclub, has just spent his life savings on a racehorse named Hi-Hat.

Tony raises some money by scamming Hackenbush in the "Tutsi Fruitsy Ice Cream" scene, selling him a tip on a horse in code—and the numerous books needed to decipher it.

Morgan, Whitmore and the Sheriff arrive to arrest Hackenbush, with a written letter from the Florida Medical Board confirming that he's a horse doctor.

A major portion of the final screenplay was written by Al Boasberg who also contributed to A Night at the Opera, but due to a disagreement with MGM, he chose not to be given any credit for his work.

[9] The original release of A Day at the Races presented the water carnival sequence in light brown sepia and the ballet scene with a blue tint.

[11] The songs in the film, by Bronislaw Kaper, Walter Jurmann, and Gus Kahn, are "On Blue Venetian Waters", "Tomorrow Is Another Day", and "All God's Chillun Got Rhythm" (featuring Ivie Anderson from Duke Ellington's orchestra).

[12] "Cosi-Cosa", a song sung by Allan Jones in A Night at the Opera, makes an instrumental cameo at the opening of the climactic racetrack scene.

"[15] John Mosher of The New Yorker was also positive, writing that "Groucho, Harpo, and Chico are in full blast again," and the film "reaches a fever pitch even beyond earlier records.

"[16] The Chicago Tribune called it a "ridiculous farce, plummed with unique gags, laugh provoking situations, fast action ...