Every dog owner wants to believe one thing: “My dog is happy.” And most of us judge that very simply. Does he eat? He eats. Does he wag his tail? He does. Does he get excited when he sees the leash? Absolutely. So everything must be fine. Or maybe not. Over the years, I have watched countless dogs. Some living in large homes. Some living in small apartments. Some with the most expensive food, toys, and beds money can buy. But after years of working with dogs, I have learned one important thing: A dog can have everything. And still not be happy. The problem is that most dogs do…