Since pets tend to drink more while traveling, it's important to take plenty of litter when traveling with your cat. For familiarity's sake, use the same litter brand as you would at home. Pets tend to shed more when traveling, so it's a good idea to keep a lint brush handy for clothing or car seats. If your dog or cat is not used to being on a leash and walking with someone, start getting them ready by practicing long before the trip. Small animals can travel in kennels secured in the car, seat belts and harnesses are available for larger animals.
Sudden stops can hurt animals just as much as people.
It's a good idea to carry a pet First Aid kit. If your pet gets motion sickness, try to give it as much cool air as possible. Always clean up after your pet. Likewise it's a good idea to pack a supply of plastic bags. Check with the airlines when flying.