I just love your dogs picture, he is so cute. I am no expert and new to this site. I have never left my dogs kenneled for more than 5 hours. Even when I used to work, I would come hm on lunch and let them out. My GSD is not alone, There are other dogs with him. I think this helps. I never leave him outside unattained at all. He is a pup though, and I have only had him 4 months. I have had dogs my whole life. Was not raised the kennel way, but believe in it now. I guess kenneling would not work for watch dogs. So, agree 5 hours, inside. Hope this helps.