For future reference: chickens are amazingly tough and can recover from some pretty bad injuries. But I think it's best to leave wounds open (we did when a dog tore up one of our hens). We just flushed the wound twice daily with sterile saline which we made ourselves and put in a spray bottle, and coated it with triple antibiotic ointment. Be sure to use the kind that does not have pain reliever in it, as that is toxic to chickens. It was a really bad wound but she was good as new in about three weeks. We kept her in the house in a dog crate. Good luck with yours, hope she recovers as well!