Separation anxiety: Dogs with separation anxiety may become anxious and stressed when separated from their owners. If you often leave your dog alone in the car, this can contribute to their fear of car rides.
Unfamiliar sounds: The sound of the engine, traffic, and other vehicles can be overwhelming and scary for dogs who are not used to them.
Motion sickness: Some dogs experience motion sickness when they ride in the car, which can make them feel nauseous and uncomfortable.
Lack of socialization: Puppies who are not socialized to car travel may be more likely to develop a fear of it as adults.
Underlying health conditions: In some cases, a sudden fear of car travel may be a sign of an underlying health condition, such as ear pain or vision problems.
Age: Some dogs develop a fear of car travel as they age, especially if they have not been regularly exposed to it throughout their lives.