We had a hen get attached by a small hawk, removing a patch of skin about 3" x 4". What was left looked just like a piece of chicken you've skinned before cooking. It was awful.
Well, it took about three months, but she healed fully, growing back all of her skin (from the outer edges inward, since there was no longer any skin over the muscle tissue), including all of the feathers! Imagine if we could bottle the remarkable healing ability of chickens, what it would mean to burn victims, etc!
But back to topic: Here's what we learned. Perhaps it will work for you:
The wound was not bleeding. There was just this huge, gaping, open area. The wound was recent, so the area was still moist.
We elected NOT to try to wash the wound (although there were a couple of specks of dirt on the surface of the open area). It would have been painful for the chicken. Plus, it might have spread infection bacteria. Most importantly, and it would have washed away the healing enzymes and cells that the hen's immune system had already sent to the area.
We also chose not to apply any kind of antiseptic, Neosporin, etc. The area was too large, and antiseptics are, by their nature, strong stuff: In addition to killing bad bacteria, they kill good bacteria, too -- the ones that can help the wound heal. Most importantly, in addition to killing bacteria, antiseptics can also kill some cells of living tissue -- the same cells that the body sets up to begin the healing process. Antiseptics can be toxic on large wounds.
What we have found is that isolation and rest, in a warm, dark, quiet area, works miracles. Here's what worked for us:
Instead, we isolated the hen in our "hospital pen". It's a plastic travel crate for large dogs, the kind with a wire door in the front. We put the pen in a warm, quiet, darkened room, away from drafts. We cover it with a lightweight dark-colored blanket, for extra warmth and darkness, leaving an open area for air flow, of course. We put water in the little dish that attaches to the door.
We put a heating pad, set to medium, on the floor of the crate and cover the floor (and heating pad) with old bath towels. We set a 4 x 4 on the floor, in case the chicken wants to "roost", but the back of the crate, where the heating pad is, is open, so if the hen wants more warmth, it can lay on the towels that cover the heating pad.
We let the hen out (or bring her out, if she is weak), every few hours for food and to be sure she's drinking. Dehydration happens quickly, and it kills.
We provide a smorgasbord of their favorite foods, including fresh, raw liver (from organically raised, pastured animals, so the liver isn't contaminated). Gently cooked eggs are popular, too. Both of these foods contain a wide range of vitamins and minerals needed for healing. They like chopped raw tomatoes, lettuce, various high-calorie seeds, like shelled sunflower seeds, etc. We also offer freshly thawed frozen corn as an energy food, especially for their last meal before "bedtime", so the chickens don't have to use the liver and eggs for energy production and can, instead, use those foods for healing. In short, we spoil them with wonderful, health-building foods. We've found this makes a huge difference, compared to providing just their normal chicken feed.
After a day or two, the hen comes out on her own, when we open the door of the crate, and walks right out to our kitchen, where "lunch" will be. When she's finished, she walks right back into the crate on her own, and settles down again. Pretty amazing.
While she's out, we replace the towels. Keeping the pen clean is very important to healing, of course.
In the case of our injured hen, the open area dried out, just the way a piece of skinned chicken would, if you left it out on the counter. And it began the healing process from there. We observed the hen closely, and there was never any sign of infection at all.
As usual, we were amazed at the healing power chickens have.
We have had huge successes, saving chickens, with our hospital-pen technique. We don't save them all, of course, but probably 95%. The secret seems to be getting them into the "hospital"at the first sign something is wrong, watching closely, and providing minimum "medical" intervention. It's hard to restrain ourselves, because we all want to think we're "doing something" to help our beloved friends, but we've found that most often, refraining from "medical intervention", and allowing Mother Nature to do her miracles unimpeded, is the best thing to do.
Hope this helps some one. Thanks for helping me with all your suggestions and ideas! I love this site!
Karlen