car riding anxiety

Question
We have a sweet quiet one and a half year old female Cavalier King Charles Spaniel named Sunshine.  My husband and I are recently retired and she goes everywhere with us in the car-to visit relatives, to go for hikes, to snowshoe, etc.  She always lies down in her crate in the back seat. We even drove to Florida last spring when she was 5 months old.  
We have given her lots of varied experiences and she is outgoing and confident.  She loves people and enjoys being with us.  
Two weeks ago when we were riding up to our vacation home she appeared very anxious in the car.  She was sitting hunched over, she was panting and she was vocalizing.  She is very quiet-she never barks but occasionally she'll cry.  This sound we never heard before.  We were heading up the Thruway and pulled off the road as soon as we got to a rest area where we walked her.  She was fine outside of the car with her tail wagging.  
As we continued on our way she once again resumed that half sit/lie position and after about 3o minutes she began to vocalize again.  
We were at our vacation home for 10 days and on the way home the same scenario occured.
We purchased several harness arrangements as we thought she no longer wanted to be in the crate.  She appeared more anxious with these tether systems.  
She has always been so calm in the car and we need to help her feel more comfortable again as we take lots of trips together.
What suggestions might you have to help us help Sunshine?
Thank you,
Linda

Answer
Dear Linda,

I'm not sure how I can help with this problem. It seems odd to me (as I'm sure it does to you too), that she has become anxious about riding in the car when she used to do so well. You are a detective now. Look for anything that has changed.

Did you get a new vehicle? Have previous rides been this long? Is there anything that occurred at the vacation home that would make her anxious about going there? Does she get anxious on shorter drives? Is she anxious before the drive? Is there anything about the drive that has changed? different luggage? Did you recently change her diet? If so, is the protein amount any different from her old diet? Different source of protein? Have you noticed any changes at home?

My first thoughts are to have her thoroughly checked by your vet. And to have your automobile checked for exhaust leaks. Good luck. Sorry I couldn't offer any definite resolutions.  

Alan J Turner
http://howsbentley.com