has anyone considered the fact that cats and dogs can have fleas and can bring them into the house? Have they considered the fact that cats and dogs can carry worms and all kinds of other diseases and parasites? Yet I bet all of you have cats and dogs, right? And in your house, right? And I bet 50-100 years ago when most cats and dogs lived in barns or doghouses, people said all this same stuff. I know of people still who think pets should only be outdoors, and my opinion is those people should refrain from having pets.
Furthermore in some European countries, animals were usually kept in the bottom floor of the residence and humans lived in the upper floor.