Thank you. I got a vet who says some airlines will let you put them under your seat (pet carriers can be found in the right dimensions for that). But it is hard to imagine finding passengers who would agree to allow tranquillized cats in cages under their seats. That's the only way they would travel. They are so shy and frightened of everything. One is 18 lbs! He would be crammed in a carrier. The luggage area has been known to produce dead pets at the end of a flight from freezing cold, low oxygen and whatever. This, and finding a place for us in PR is what is stopping me. It will be so traumatic for my shy old cats. I'll need to be tranquillized by the end of a flight like that, too.