Fawlty Towers S02E06 - Basil the Rat (a.k.a. Rats)

The local health inspector issues a long list of hygienic aberrations which the staff must immediately sort out, or else face closure. After Manuel's pet rat escapes from his cage and runs loose in the hotel, the staff must catch it before the inspector finds it first. At the same time, they must try and discern which veal cutlets are safe to eat after one covered in rat poison gets mixed up with the others and almost every subsequent guest orders veal.