I am afraid I would have to say that the oldest dog I ever brought into the house when my children were young was my current doberman, Raven. My daughter was 3, and Raven was just around a year old. She was totally shattered by abuse, spirit broken and afraid of her own shadow, reactive to children and men, who provided the bulk of her abuse before she came here. To this day, at 10 years old, I watch her carefully around young children, and have chosen at times to remove her from the room if children are present. However, as stated before, my children were raised with large dogs from birth, and extremely dog savvy. I also had a complete understanding of Raven's previous history, witnessed the abusive behavior (and stopped it), and was aware of the triggers, as well as her reaction to the triggers. Rescuing a large breed adult dog from a shelter is a wonderful, caring, loving thing, but it is a crap-shoot if you have very young children in the house. IMO.
Stella