We just got back from a trip from the USA to Costa Rica with our French Bulldog in cabin and did not have any real trouble. We used a soft side carrier and she slept most of the nearly 4 hour ride. Our only hassle was coming back into the U.S.A. when the Agriculture people had their dog sniffing bags and the beagle alerted on one of my husband's bags...they took a little longer going thru our things due to this...the culprit? A ziploc of dry dog food we packed so that her stomach would not be upset by new food in a strange place, we ended up getting thru after they confiscated the dog food. We were advised next time to leave the food in it's original bag so they can see the contents.....? strange but whatever, we can do that, and in fact WOULD have willingly/gladly done it this time if we had KNOWN.......I didn't find it anywhere in my pre-flight research.