I does sound like stress. What do you have him in?
Also I would just start get him used to the car. By just putting him in there with the car not running. Talking to him. Give him a treat. Find a special treat that you will only use in the car. A special toy. Start slow. 5 mins. Every day. Then longer. Make it fun. Then turn on the car and do the same thing. Then drive to the pet store for a treat. Make it a fun experience. Good luck keep us posted |