Oh so very sorry for OP. I had this happen to a great hen years ago. I rushed to vet. Shock will kill them fast. My hen wasn’t conscious. They put her in an oxygen tent immediately. I was sent home with Baytril. She lived. Her wounds were horrendous. They healed and I had her for some years. I had a opossum that had a hen by the head on the roost one time and I shot him dead. I got Baytril. I thought her eyes were gone but turns out, they were just swollen shut a few days. She was two years old then but went on to live to be 9 years old. Shock and infection are the thing that kills them. They can recover from the wounds.You might want to read post #25