I just read that some dogs shake as a prelude to or as the only manifestation of a seizure. Even if it is just a petit mal seizure - they can manifest seizure in so many ways and shaking is one of them. A dog can have a seizure like this from dropping blood sugar and many other causes.
I would sure encourage your friend to take the dog to the vet if it continues when the dog is not cold, hungry, scared or anxious. If a dog is just lying about shaking, there is probably another cause for that and the animal could be ill or in serious pain.
__________________  Jeanie and Tibbe One must do the best one can. You may get some marks for a very imperfect answer: you will certainly get none for leaving the question alone. C. S. Lewis |