Shaking could be caused by chemical poisoning. My 7 week old puppy ate the yellow bubble stuff u fill gaps with off a wall & started dribbling uncontrollably. I was so scared she was going to die. I kept cleaning her mouth & chest from dribbling & wrapped her up to help warm her up. While I was trying to arrange to start work late so I could take her to vet, my puppy stopped dribbling & her shaking subsided within 5 minutes of dribbling stopped so I tucked her up in a warm room & had a Neighbour stay with her. She was fine & I blocked off the wall in question. Any chance of poisoning in your house.