Just something to consider Petting the dog when he is shaking for most dogs is rewarding the shaking behavior and in the end you are likely to get more. Just as it is advised not to comfort a dog that is afraid of thunderstorms or large noises. It is very much a human reaction to the circumstances to comfort the frightened it just happens to be a foreign reaction in dog language.
Thunderstorm tips
CAUTIOUS CANINE, 2ND EDITION