One searing memory that I can't unsee is a video clip taken during the New Orleans evacuations after Katrina. A poodle is jumping up at the closed door of a bus and obviously bewildered that he can't get in and be with his owner.
I have thought many times about that video. If I couldn't smuggle that pet on board, I would hope I wouldn't be able to abandon him/her, and we'd take our chances together.