A passenger’s pet is supposed to remain under their control and not come out of the carrier inflight. Some crews enforce that more aggressively than others. And on a recent Southwest flight, one French bulldog came out – and wandered around the aircraft.
This went on long enough, and the bulldog made it far enough around the aircraft, that flight attendants made an announcement asking whose dog it was? And nobody answered. Eventually, it turned out, that the dog wandered away while its owner was asleep inflight.