Adapted from a segment of the graphic novel "Garfield: His 9 Lives".
In the original story, all the characters were cats. Notice the human characters in this special all have cat-related named: Kitty, O'Tabby, Felix, etc.
In Spayed's office is a picture of a criminal wanted "Dead or Alive". It's the picture of Jon Arbuckle, Garfield's owner.
Despite the show's title (and some noticeable bullet holes in a brick wall in the background of one scene), there isn't a single bullet fired in the entire special.