A friend of mine tried to get their dog ready for baby by buying a doll about a month before the baby was due, wrapping it in a blanket and carrying it around the house, treating it like a real baby. At first their dog thought it was a toy, but they very quickly taught her that baby was NOT a toy-no biting, nipping, chewing and they even taught her to recognize the world gentle and associate it with certain behaviors around the baby. I'm not sure if this would work for every dog (theirs was a beagle/yellow lab mix), but it definitely worked for them. Lila was the best dog ever for all three of their children.