<P> In 1998, Disney's copyright on Pluto, set to expire in several years, was extended by the passage of the Sonny Bono Copyright Term Extension Act . Disney, along with other studios, lobbied for passage of the act to preserve their copyrights on characters such as Pluto for 20 additional years . </P> <P> Pluto first appeared as a nameless bloodhound tracking the escaped convict Mickey in the film The Chain Gang (September 1930). A month and a half later, Pluto appeared as Minnie Mouse's dog named Rover who comes along with her and Mickey on a picnic . By his third appearance, in The Moose Hunt (1931), Pluto is Mickey's pet, now named "Pluto". </P> <P> Several months had passed between the naming of what was believed to be the ninth planet, Pluto, on March 24, 1930, and the attachment of that name to the dog character . Venetia Burney (later Venetia Phair), who as an eleven - year - old British schoolgirl had suggested the name Pluto for the planet, remarked in 2006: "The name had nothing to do with the Disney cartoon . Mickey Mouse's dog was named after the planet, not the other way around ." Although it has been claimed that Disney named the dog after the planet, rather than after the mythical god of the underworld, this has not been verified . Disney animator Ben Sharpsteen said "We thought the name (Rover) was too common, so we had to look for something else...We changed it to Pluto the Pup...but I don't honestly remember why ." Disney says they have no documents to support or refute the connection . Unofficially, even Disney's animators believed that Walt Disney chose the name to capitalize on the sensation of the newly named planet . </P> <P> Pluto was initially a minor character until 1934 when Disney animator Norm Ferguson gave the dog a key role in the cartoon Playful Pluto . Pluto becomes entangled with a sticky piece of flypaper, and Ferguson expanded the sequence significantly . The segment became a classic, demonstrating how Disney artists can take a simple circumstance and build humor through a character . </P>

How did pluto the dog get his name
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