You'd better inquire the airline company which you are going to use in advance. In China, if we want to bring a pet aboard, we should go through the quarantine formalities at the animal quarantine station. Pets will be vaccinated and get the papers for quarantine inspection. The handling charge is claimed, of course. But I don't know the American standard. In China, it's not expensive. It's less than CNY100. These proof materials have a valid period. That's to say, you must ship your pets within this period. So, as I mentioned above, you should consult the airline company first.