Some of the footage was from a cartoon never finished: "For He's a Jolly Good Fala". That cartoon featured Franklin D. Roosevelt who died during production.
The burglar calls Shep a quisling, another name for a turncoat. It comes from the Norwegian politician, Vidkun Quisling, who was a Nazi collaborator in WW2.
The White House can be glimpsed in the background of the heroic dog newspaper photo.