Interesting comments, thank you. I found this information on the AVMA site:
Q: What should I bring with me on my trip?
A: You should bring the following items with you:
Your veterinarian's contact information
List of Veterinarians and 24 hour Emergency Hospitals along the way and close to your destination
To find a listing of Veterinarians & Pet Emergency Hospitals in the United States, contact:
AVMA Search
State VMA
American College of Veterinary Emergency & Critical Care
Veterinary Emergency & Critical Care Society
National Animal Poison Control(ASPCA Web site)
888-426-4435
Identification
Current color photo of your pet
ID tag should include:
Owner's name, current home address and home phone number
Travel ID tag should include:
Owner's local contact phone number and address
Contact information for your accommodations (hotel, campground etc)
The microchip registration should be updated with your current contact information including a cell phone number.
Medical Records
Current copies of your pet's medical records including pre-existing conditions and medications (especially when re-locating or traveling out of the country). For travel within the United States, a brief summary of medical conditions would be sufficient.
Certificate of Veterinary Inspection (health certificate)
Proof of vaccinations (Proof of rabies vaccination required) and other illnesses
Requires an examination by a licensed and accredited veterinarian to make sure the animal is not showing signs of disease.
Acclimation certificate for air travel
This is only required by some airlines, so check to see if your airline requires this.
Items for your pet
Prescribed medications (adequate supply for entire duration of trip and several days' surplus supply, just in case)
Collar, leash, harness
Crate
Bed/blankets
Toys
Food and cool, fresh water
Food and water dishes
First Aid Kit for your pet
*For more information on Pet First Aid and First Aid Kits, please go to the AVMA Pet First Aid Site