Hi, my Shih Tzu is 12 years old and he keeps shivering (not violent shivering, but shivering nonetheless). He will not eat his food, although this is not unusual as he doesn't always want to eat. However, this time he just seems very sleepy and not interested. I don't drive and I'm home alone with him so I can't take him to the vet right now. Please help!! What should I do?