She may likely have gotten caught up in something...
What happens in most areas on a turkey is that the wound starts as a moderate and simple to fix cut, once cut, the skin recedes back from the cut and exposes a huge portion of the turkey... usually by the time you find them they are too far gone...
I had one of my best hens get morbidly attacked by a raccoon (turnabout is fair play, he won't do it again, I promised him.) My wife was out of state and I had to put about 50 stitches into her on my own. There were actually layers of muscle that had to be sewn back together in her neck. To my surprise, she survived and is laying fertile eggs again...
-Shad