For 30+ years I have had all kinds of injuries to chickens. I IMMEDIATELY call the vet. He talks me through it & sets me up with antibiotics & salves to be picked up by me at my earliest convenience. Meanwhile the hurt birds recuperate in first floor bathtub. I actually had to sew one hens skin together (I only have an EMT license), because birds don't have skin attachments to hold the skin in place, like mammals/people do. She actually grew a new skin, complete with feathers & all, under the 8"x8" damaged skin & shed the old skin. It took about 3 months before she went back out, and when she did she let everyone know (chickens), in NO uncertain terms, she was back & don't mess with her. Chickens blow me out of the water all the time. Call the vet! ONLY FEED CHICKEN FOOD!!! They are not people they have special nutritional NEEDS. Call the vet!!!