Having said all this about children not being 'part of the pack' there are many, many foster carers who have dogs which cope admirably with different children coming in and out of their lives. The dogs are subject to assessment from the very start, but I have assessed families with German Shepherds, Rottweilers, and the much maligned Staffies, all of which have gone on to live with strange children and be an important part of those children's lives. I would go so far as to say that the right dog has sometimes been a lifeline to a child who has had damaging and dysfunctional relationships and has learnt to relate to the dog before building trust with adults. So I guess this brings us back to the starting point which is good owners make good dogs, whereas bad owners can do the opposite.