Walt Disney originally didn't want to include the 'Bella Notte' spaghetti-eating scene, now one of the most iconic moments in the whole Disney canon.
To maintain a dog's perspective, Darling and Jim Dear's faces are rarely seen.
CinemaScope presented some new problems for the animators. The wider canvas space made it difficult for a single character to dominate the screen, and groups had to be spread out to keep the screen from appearing too sparse.
In the film, Tramp never calls Lady by her actual name. Instead, he calls her by the two nicknames: "Pigeon" ("Pidge" for short), and "Kid".
In making this film, Walt Disney claimed that it was a "fun picture" to make (another example of such a film was Dumbo (1941)), because it was an original story and was easily adjustable as they made the film and got to know the characters - there were no pre-existing storylines.