For instance, I checked with Delta last year and they told me they have a service called Dash which allows the pet to take the very next available flight out. I was assured at that time that the layover would never be more than an hour with this service, otherwise the wait is up to four hours long. Of course, the ideal situation would be to travel with your pet and book a non-stop flight. And of course, make sure your pet is healthy before beginning a journey that will be very stressful to your pet. Be sure to check with the airline you are planning to travel with.
Most airlines do require a health certificate.
The U.S. Department of Agriculture sets up guidelines for airlines to follow regarding shipping of animals, so if you feel that your pet was not properly handled, file a complaint with this agency. If you must take it along, consult with your veterinarian as to what medications and arrangements might best suit your pet's needs. If traveling in the United States take along your rabies vaccination certificate and a health certificate. If traveling to other countries you should check to find out what documents are required. Dogs and cats should be at least 8 weeks old and should have been weaned for at least 5 days before they travel.