I've seen many dogs tremble or shake when very excited, wanting attention or wanting something with all their heart. Usually affects of excess adrenaline rush. Imagine a large surge of adrenaline from disappointment could do the same thing. Did it just start or has he always done it?
__________________  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 |