It is strongly advised that you should never feed your dog before beginning your journey, as dogs have a tendency to suffer from car sickness. To be safe, feed it at least an hour or two before starting your trip. Besides, you can also take your dog for a nice walk or to the dog before heading out. This will help it to relax during the journey. Also, reduce the portion of food during the last meal before the journey. The same rule applies to water as well. Carry ample food and water with you, to ensure that you can readily provide it with food and water if required during the journey.