Small pets weighing up to 20 pounds are allowed in Coach Class only. Larger dogs weighing up to 50 pounds can travel in designated train areas but must be booked in advance.
How do you travel with a medium sized dog?
Get a well-ventilated, size-appropriate carrier that meets your airline's requirements. Your dog will have to remain in the carrier for the duration of the flight, so they must be comfortable and should be able to stand, sit, and turn around in the carrier.