The Marx Brothers' seventh film, released in 1937 and following closely in the same mold as their previous one, A Night at the Opera.Judy Standish's (Maureen O'Sullivan) sanitarium is under threat of being taken over by unscrupulous businessman J.D. Morgan (Douglass Dumbrille), who wants to demolish it and expand his real estate monopoly. The only hope for Judy is if she can keep the wealthy hypochondriac Mrs. Upjohn (Margaret Dumont) as a permanent patient, who will only stay if the sanitorium hires her favourite physician, Dr Hugo Z. Hackenbush (Groucho Marx). Unfortunately for Mrs. Upjohn, Hackenbush is actually a confidence-trickstering veterinarian, who has to avoid being caught out by either Morgan's cronies, the Florida Medical Board or Mrs. Upjohn.Meanwhile, Chico Marx and Harpo Marx play a sanitarium worker and a former jockey who have to save Hackenbush from a Femme Fatale employed by Morgan, while simultaneously trying to get the racehorse owned by Judy's fiancée Gil (Allan Jones) into race-winning condition.Not to be confused with the 1976 Queen album A Day at the Races, which was named after the movie.
In addition to the usual tropes exhibited by the Marx Brothers, this film provides examples of:
- Accidental Misnaming: Chico keeps pronouncing Groucho's character Hackenbush's name as "Hackannapuss".
- Call Back: to Duck Soup in the barn musical number with the line "All God's children got swing." Previously it was "All God's children got guns."
- Grande Dame: Margaret Dumont again.
- Induced Hypochondria: The reason Hackenbush is so well trusted by Mrs Upjohn:Mrs Upjohn: Why, I never knew a thing was wrong with me before I met him.
- Nonverbal Miscommunication: When Harpo tries to warn Chico about the frame job against Groucho. He gets it eventually.
- Real Joke Name: Averted, Groucho Marx's character was going to be Doctor Quackenbush, but MGM's Legal department heard from an actual Dr. Quackenbush complaining, so the name was changed to Hackenbush.
- Spiritual Successor: The basic plot is markedly similar to the previous Marx Brothers film, A Night at the Opera, except with horse-racing instead of opera.