Continuity mistake: When Lady and Tramp are walking through the zoo trying to find something that will remove her muzzle, they approach an alligator's cage to see if he'll help out. Lady and Tramp are standing in between a couple of steel bars at first, but in the next shot a bar appears between them instead.
Continuity mistake: In the dog pound scene, one unlucky victim is taking the "long walk" to be put down. Towards the end of the corridor, he goes past three cells. But in the following shot after Lady asks the other inmates where the dog is headed for, only two cells are present. (00:57:00)
Continuity mistake: When Tramp is scratching on the back door of Tony's Restaurant looking for some breakfast, you can see an ad posted on the brick wall for Uncle Tom's Cabin dated August 6,7,8. But once Joe peeks through the door to see Tramp, August is now abbreviated on the ad. (00:16:10)
Continuity mistake: After Tramp gets his breakfast bone from Tony's Restaurant, he carries it behind a wooden fence and starts chewing. Pretty soon a horse drawn dog pound wagon rolls by, and a worker gets out to nail an impound notice four boards away from him. But when Tramp walks over to read what the notice has to say, it's now nailed six boards from where he was just a moment ago. (00:16:40)