I have a Jack Russell Terrier. He is 10 years old and he's usually well mannered. Gets along with other dogs. Sometimes when I bring him to my moms, who has 2 yorkies who are nice, hell seem fine most of the time but out of no where hell start shaking and panting. Not sure why? When I leave for work he starts whining and barking. Then I leave and he always jumps at the door and slams it behind me. The vet a while ago said nothing to help me.