If it has food, water, and proper shelter, those are the only requirements for life and thus, the dog is adequately being taken care of. I don't think there's any "dog must have x amount of human interaction per day" clause in any law. It doesn't seem fair, and IMO, I would not tether a dog with a tether that short. But, unless there is law regarding how long a tether should be, there's nothing AC should or can do.