United
Types of pets allowed: Domesticated cats, dogs, rabbits and birds (excluding cockatoos) older than 8 weeks.
Maximum weight: No limit, but must fit comfortably in carrier under seat.
Cost: $125 each way with an additional $125 service charge for each stopover of more than four hours within the U.S. or more than 24 hours outside the U.S.
International?: Rules for international in-cabin pets vary — contact the United customer-contact center for info on specific flights; pets are not permitted on flights to, from or through Australia, Hawaii or Micronesia.
