My dog just turned one and has been going to the door to whine every time he wants to go out. The problem is that he whines at the door every hour and a half or two hours. I know he can hold it for a lot longer than this as we leave him for over 8 hours in the house when we are gone and he won't go. Sometimes he whines at the door and won't even go to the bathroom when we get outside. I don't want him to think that whining at the door is bad though. What do I do?