Right now I have two dogs, a golden lab (8 years old) and a golden retriever (10 months old.) Lately I've been thinking of adding another dog to the family but this time I wanted it to be smaller. Do you think they would get along? Or is it bad to mix small and big dogs in the same household? My fear is the little dog might get hurt... Also, does anyone know of a small-medium sized dog with an overall calm and relaxed personality type?