In 1937 legendary Disney story man Joe Grant approached Walt Disney with some sketches he had made of his Springer Spaniel named Lady and some of her regular antics. Disney enjoyed the sketches and told Grant to put them together as a storyboard. When Grant returned with his boards, Disney was not pleased and the story was shelved.
In 1943 Walt read in Cosmopolitan a short story written by Ward Greene, called Happy Dan, The Whistling Dog. He was interested in the story and bought the rights to it.
By 1949 Grant had left the studio, but Disney story men were continually pulling Grant's original drawings and story off the shelf to retool. Finally a solid story began taking shape in 1953, based on Grant's storyboards and Green's short story. 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. Grant didn't receive credit for any story work in the film, an issue that animation director Eric Goldberg hoped to rectify in the Lady and the Tramp Platinum Edition's behind-the-scenes vignette that explained Grant's role.