The crew found it difficult to find a balance for Mittens' appearance, between her neglected mangy fur, her hooligan side due to her miserable life on the streets and parts of softer fur still visible from every angle.
(at around 50 mins) When Penny is printing "LOST DOG" flyers, the last 4 digits of the phone number on the copier are: 8423. This makes the number (877) 504-8423. 877-504-8423 is a number reserved by ABC for movies and TV series. Calling it will provide the following short tape recorded message: "Thank you for calling ABC. The number you have reached is a fictional non-working number used for motion picture and television production."
In order to properly animate Rhino, the crew adopted a real hamster which they called Doink and filmed it from beneath while it was walking on a sheet of Plexiglas. Thus they were able to see how Rhino would walk in his plastic ball.
Since the word "bolt" can be used as a vulgar word meaning a male organ in Russian, the film was released as "Volt" in Russia, with the hero called Volt. The film is also called "Volt" in Hungary, France and for the French-language release in Canada. Besides, the name of the film is "Lightning" in Croatia, Slovakia, Estonia and Poland and "Thunder" in Bulgaria.
Storyboarded but not animated was a scene in Las Vegas, where Bolt (who was just passing through the city with Mittens and Rhino, and foraging for food) is confronted in a dark alley by two Doberman Pinschers, who proceed to brutally bum-rush him, and rip off his collar (complete with ironic quick cuts of clips from the "Bolt" TV show playing on a big TV display, which Rhino was watching, in the city nearby). Left for dead by the two dogs, Bolt, disillusioned, realizes that his "super powers" are not real (which was further emphasized when Bolt then sees the program for himself). The producers decided to nix this scene, as they not only felt that it was way too dark, but it didn't fit into the story structurally.
Another sequence storyboarded but not animated was another variation of Bolt realizing that his super-powers are not real, this time, through dramatic failure: Bolt, Mittens, and Rhino were traveling along a bridge over a river. Rhino accidentally falls off the bridge, and to Mittens' terror, Bolt, still believing himself to have super-powers, jumps in to save him. The rescue doesn't quite go as Bolt expected, and he almost drowns, but still tries hard to save Rhino. When Mittens helps a shaken Bolt back to shore, they find Rhino's hamster ball, believing him to be dead, until they see a wet, awestruck Rhino, who thanks Bolt for saving him. But Bolt realizes that he didn't really save Rhino, and feels the lightning bolt shape on his side, which smeared from the water. The scene was nixed, because, once again, it didn't fit into the story structurally, and it was felt that something more poignant had to be done with this scene, which is what was done in the final film.
Once the replacement animation team was in place, following a swap around in directors and the film's vision, the production had only 18 months to complete the film, instead of the usual four years that a computer animated film takes to produce.
The storyline of the Bolt TV show is reminiscent of the Nickelodeon show Inspector Gadget (1983): The villain is named Dr. Claw, who also has a pet cat; Inspector Gadget's niece (who is one of the main characters and fights Dr. Claw) is named Penny, and she has a hyper-intelligent dog named "Brain".
Originally developed by Chris Sanders (creator and co-director of Lilo & Stitch (2002)) as "American Dog", with a similar storyline, but with major location and character changes. The titular dog, named Henry, originally had much more of a "Stitch" look, the character of Mittens was originally Ogo, a male cat with an eye patch who worked as a mechanic in a junkyard (this character eventually became the star of Sanders' personal webcomic, "Kiskaloo"), Rhino was originally an oversized radioactive rabbit, and a lot of the movie took place in the deserts of the American Southwest (similar to the location of Pixar's Cars (2006)). Sanders was replaced by Chris Williams and Byron Howard after John Lasseter become CEO of both Disney and Pixar, and the project was overhauled in late 2006, and he left Disney to work at Dreamworks.
While Bolt believes that he has super-powers he is self-confident, but when he finds out that he is not a super-hero his self-confidence vanishes. This is a clear case of Dunning-Kruger effect, situation when one's initial self-confidence is high due to his/her lack of knowledge which decreases in par with knowledge and increases again when the one becomes expert.
Look and lighting director Adolph Lusinsky and his team traveled to several of the film's "real-life locations" such as an Ohio trailer park, the San Francisco docks, New York streets and the desert surrounding Las Vegas to study how the light in those places interacted with the scenery.
In France, all the cinemas carrying the 3D version of the film showed it exclusively in its French dub. As such, viewers who wanted to see the film in English (with subtitles) had no choice but to see the 2D version.
The diesel locomotives pulling the freight train that Bolt swings onto from the bridge are EMD SD70MACs, owned by CSX. Some of the train cars are Gunderson 48' All-Purpose well cars, owned by Trailer Train Corporation (TTX).
The trivia item below may give away important plot points.
When the animals arrive at the Hollywood studio, a car pulls up and the security guard is distracted by the driver who has an appointment with "Joe Mateo". Joseph Mateo is one of the studio artists listed in the movie's credits.