Service animals are allowed in San Francisco International Airport and on the AirTrain. Non-service animals and pets must be in crates at the SFO terminals and ready for travel. Leashed animals are permitted in SFO's five Animal Relief Areas with drinking bowls. All pet relief areas are fenced and landscaped, wheelchair accessible, and open 24/7. Before traveling, ask your airline about required veterinary papers, kennel sizes, and restrictions.