My Bubba gets car sick. I asked my vet for some meds, I paid eleven dollars for two doses of Benadry I now cut a benadryl in half for him.. I called the vet the day we were leaving once when I didn't plan ahead and he gave me the dose for bubba, you can also google the dose.

Trust me it wasn't fun having him puke on a pillow on our way camping, we now put towels down also but the benadryl does seem to help him.