Canned Feud (1951)

Continuity mistake: When Sylvester tries to open the front door, you can see there is nothing under the handle, but when Sylvester opens the letterbox in the next shot, a key hole has suddenly appeared.

Trivia: In the cartoon's opening title card, there is a tin of cat food with "Farren's Finest" on the label. This is a reference to the assistant animator, Jack Farren.