The fear that I'll be an annoyance to other passengers is what worries me the most about my upcoming flights with a cat. I can't make sure that the cat is 'empty' beforehand, because it's an intercontinental move with at least 24 hours of travel time - fasting her for that length of time, plus the night before, would be cruel and dangerous. No vet on the planet is going to say that withholding food for 36 hours is ok.

I figured I'd do a trial run with tranquilizers beforehand, and have them on hand to administer if she starts yowling, but I can't do that without opening the carrier. And if she does soil the inside of the carrier, I can't imagine just letting it sit until the plane lands. No amount of air freshener is going to get rid of the smell if the source hasn't been cleaned up.

I guess if she starts howling or makes a mess, I and everyone else on board will have to listen to it and smell it for the entire trans-Atlantic flight. I'm not sure it's fair to get upset with irresponsible pet owners when airline and FAA rules specifically prohibit them from doing anything to solve the problem. Realistically, though, I'd probably do exactly what this woman did (minus the taking it out for no reason and being rude to the FA), just out of consideration for the other passengers. The cat probably doesn't care all that much about having to smell its own waste for the duration of the flight, but I'm sure the humans on board would rather not.