Within 10 days of your departure, visit your vet's office for a check-up to ensure that your pet is healthy enough to travel with you. Your cat needs to be up-to-date on her shots, and you should get written proof of her health with a signed health certificate (also called a Certificate of Veterinary Inspection) and vaccination status (including rabies vaccine status) to take with you.
You may have to show that paperwork, especially if you're crossing state lines, traveling by air, or leaving the country. If you're planning to visit a foreign country, check with the embassy or consulate about pet travel regulations. Some airlines also require a separate acclimation certificate to prove that your cat can handle the chilly temperatures in the holding areas, where she may have to wait an hour or two before being put on the flight.
Write up a list to take with you that includes your veterinarian's phone number, as well as the numbers of a local veterinary hospital in the city where you're headed and the national animal poison control hotline (888-426-4235). To find a listing of veterinarians and emergency pet hospitals at your destination, contact your state VMS or the American College of Veterinary Emergency and Critical Care.