Could a hawk do this? It looks too clean to be one of my dogs. I found her in a stall with our LGD puppy but there was no blood on either dog (we have 2) and the wounds were already clotted. The pup was laying on the other side of the stall ignoring her. I just don’t know.
I'm sorry you had to experience this event. Unless your 100% sure your dog(s) are perfectly trained around chickens, your dog did that to your girl. That means when you say "Leave it" they know. Example: I can put a juicy cooked steak on the floor and say "Leave it", come back 6 hours later and that Steak is untouched on the floor.
They didn't mean to do it but, that prey drive kicked in and without advance obedience training they could not help themselves.
The chicken fluttered then got pinned down by the impulse of the dog and its mouth left an open wound.
I have a GSD, they are prey driven herding dogs. She nabbed two of mine as yours. It took me 3 weeks of consistent training to break her after that "Blood taste". I did train her and I am 99.8% sure, it won't happen again but, I NEVER leave her unattended with the chickens because of that 2% and her taste.
It's what GSD do! It's that Prey drive then the innocence with that long tongue that cleans up any evidence, you have no proof.
I'm sorry about your chicken but, Now you Know your dog did that.
Sorry.