Check out the Lost Media Wiki’s article on American Dog!!
American Dog was a Disney movie written and directed by Chris Sanders, that was due to be released in 2007. The protagonist of the film was a canine actor named Henry, who stars in his own show where he's a secret agent. While filming an episode, one of the stunts goes wrong and Henry blacks out. He wakes up on a train in the Nevada desert, 2000 miles away from home. Henry must make new friends, including a one-eyed cat and a giant, radioactive rabbit.
Ultimately, the movie was considered too surreal and too bold. Sanders was kicked off the team and replaced by Chris Williams and Byron Howard, this move spurring Sanders to leave Disney entirely. The movie was soon after reworked into Bolt, which was released in 2008. Notably, Sanders reused the eyepatch-wearing cat in his webcomic, Kiskaloo.
Test footage from the film, posted belo, was shown at SIGGRAPH 2005