I have to pet sit a Great Dane. He knows me and I know him quite well. Last time he went to a kennel, he had anxiety so bad that it led to hysterical blindness. So now he will be left at home and I will see him 3 times a day. I am afraid that if he gets too anxious that it may cause real harm to him (ie stomach turning over). How or what can I do to make this time easy on him? Any information will help me out alot.