Regular dogs do not belong everywhere. I was riding an incredibly crowded subway this weekend, and a pug was sitting in one of the seats. While the dog's presence amused some subway riders, I was slightly annoyed. Why the owner couldn't put the pug on her lap so somebody else could sit down, I don't know. There is a clear exception to this rule, and that is service animals . Service animals are essential to the people they serve and are allowed in any business or public place by law. The import…