I have a beagle puppy who is four months old. He is normally a happy, active puppy who goes around licking everyone and loves to eat. Well three days ago that started to change. He started the day okay. Then as the day when on he go to where he was the same but he didn't eat any of his dinner. The next day he old ate what I hand feed him and he would run to everyone but no licking was involved. Today he is moving really slow and avoid everyone. What do you think is wrong with him?