Welcome to YT ! I had my Sophie shipped to me as a puppy from an AKC Yorkshire Terrier breeder in Missouri to Michigan. She flew with Pet Air, an organization that flys show dogs and pets around the world and who take great care to be sure the puppies are comfortable. She was vet checked before she flew and if there was a layover they would take the puppy out and exercise her and replenish any food and water. The dogs are always first on and first off the flight. They do not fly in the cargo hold. Sophie's flight was only five hours and she arrived in excellent condition. She seemed very happy and healthy when I received her. I would use Pet Air again if it was necessary as it was in my case.
Jackie & Sophie