How long before my baby can play with my dog?

I think it depends on your comfort level. You can let your dog interacts with your little one as early as when your bub is in mommy's belly. Let the dog knows that there will be a new member to the family. I think it should be ok to let your dog plays with the baby as soon as when the baby is looking for things to play (of course with supervision from adult). Home dog generally is harmless. They will only attack when they feel threaten.