Emzyyy - I think you may have missed the parts where the OP's young daughter had been hitting the dog with a SHOVEL and screaming at it and the dog was STILL heading for more chickens. The dog had what is called blood lust. It would have kept going until all the chickens, ducks, turkeys were gone and quite frankly I'm surprised it didn't turn on the OP's daughter. I would hope that if you were in such a position where a dog is on your property, attacking your chickens and wasn't stopping when you were hitting it with a shovel, that your parents would do the same as the OP's.
A word for those people that don't seem to understand the damage an unknown animal can do. Many years ago, I lived in Dallas. I was in the cat/kitten adoption room at the humane society when a cat got loose and I went to help get the cat back into the cage. The poor thing looked absolutely terror stricken. The SECOND I picked it up, it attacked me. I'm not talked about those simple scratches a PO'd cat gives to get you to release, I'm talking biting down to the bone SEVERAL times and scratches that went from my wrist to my elbow. In the 10-20 seconds I held him/her, the cat was trying to kill me. I don't remember whether I let it go or if someone came and got it off anymore (I'm pretty sure I let it go). As it turns out someone had mistakenly put the cat in the adoption room to recover from having been neutered/spayed as part of their catch and release program for feral cats. There were NO signs that this cat should not have had its cage door opened (remember, it was in an adoption room). I ended up with an infection from the bites and scratches and was told by the doctors at the ER that I was lucky that is all that happened. My point is: if you don't KNOW the animal, you don't know how it will react and you should take all the precautions necessary to protect yourself and your family. I don't blame the cat for reacting the way it did but I do blame the person that made the decision to put that cat where they did. To this day, I remember the fear and hatred that was in that cats eyes. I do not doubt that the cat could have done far more damage that it did.