Lady and the Tramp was based on a short story written by Ward Greene, called Happy Dan, The Cynical Dog, published in the mid-1940s in Cosmopolitan (a literary magazine at that time), about a mutt from the wrong side of the tracks; and a story line worked on for several years by Disney story man Joe Grant and others at the Disney studio, about a Cavalier King Charles Spaniel named Lady, based on Grant’s own pet, a Springer Spaniel named Lady (his dog was brown and white while Lady was honey-colored all over). Greene later wrote a novelization of the film that was released two years before the film itself, at Walt Disney’s insistence, so that audiences would be familiar with the story. Presented in an aspect ratio of 2.55:1 it is, to date, the widest film that Disney has ever produced (along with Sleeping Beauty that was also produced for an original 2.55:1 aspect ratio, but was never presented in theatres this way ; the film is nevertheless presented in its original 2.55:1 aspect on DVD and Blu-ray Disc Platinum Edition release).
 
Lady and the Tramp [ en.wikipedia.org ]