I've done the one dog thing and now I have two. I think it is essential (depending on the dog of course) to let dogs have canine companions all the time. But if you cannot afford a second dog, don't get one! They are more money, more trouble, and more training. But they are great. My two keep each other company and love being together. My first dog was an only dog, raised as an only dog, and thus was never around other dogs hardly. He hated them because of that. Bringing a second dog into our home with him would have been a mistake. So it depends on the dog too.
