Since hubby and I both work, I have always had at least two large-giant dogs in the house, currently have three, and when my Mom is away from her house I have four for weeks at a time. I do have a fenced in back yaerd where they can run around freely, but other than that I live in an urban area and keep them leashed outside of my property. That is not to say that they have never gotten loose, but it happens infrequently(the last time was probably three years ago) and they are obedeince trained well enough to beat it home when called. I think that it depends on the individual animals, their training and prey drives as to whether they are a threat to other animals or people.
I do agree that the number of pets that you have is your decision-and your responcibility . Having more than one dog is much like having more than one child, double the work,but also for us anyway, double the fun.
Stella