Also, if this is the second attack in as many days, I think you will continue to lose livestock until you trap and/or kill the predator. Your state or county Dept of natural resources will have a list of certified trappers. I would keep all the ducks inside like in the garage 24/7 until the...
I've had several chickens with similar wounds (from an aggressive rooster). I sprayed them with BluCote and isolated them (in a cage In the coop). They eventually healed maybe 4-6 weeks later. They have bald spots on their scalp.
