As I have previously reported, airlines have different requirements about carrying pets on board. Air France (and its code-share partner Delta) is one of the few pet-friendly airlines, allows cats and dogs of five kilograms, or about 11 pounds, or less to travel in the cabin. American Airlines does not accept carry-on pets to or from Hawaii, on trans-Atlantic or trans-Pacific flights, or to Central and South America. United Airlines allows "small dogs or cats" to travel under the seat in a container 22 inches, or about 56 centimeters, by 14 inches by 9 inches; larger animals, including guide dogs, are consigned to the hold. British Airways requires pets (other than guide dogs) to be checked in as excess baggage. But they do get to travel in a heated, or air- conditioned, section of the hold and are "taken to the plane personally" by ground staff.