As Penny sneaks off, Brutus and Nero have collars on, with chains attached to the right side of their necks. In a reverse shot the chains are attached to the left side of their neck.
In the scene where Bianca & Bernard first fly with Orville the bird, they fly straight down beside a building. In one window that they pass, there is a topless woman in it. This was corrected about 4 years ago, and can be seen on the original VHS release if you go frame by frame.