I am dogsitting my sister-in-laws 9.5 yr old lab while she is on her honeymoon. She warned me that Scout had started having these times when he would shake and get distressed, but i had never seen him do it. Last night at 3am Kali came to get me and I found Scout shaking and drooling, and though he was standing he seemed to be having difficulty walking. I sat with him and stroked him and eventually he settled, we went outside and he went back to sleep. He seems perfectly fine today. Has anyone had an experience like this? I know she has brought him to the vet and they seemed to think it was a stress response. but I am not sure what was stressing him at 3am.