I found one of my hens this morning unable to hold her wing up. I thought maybe she broke it, but when I picked her up, I noticed a lot of swelling on the underside around the wing bones. The swelling goes all the way down to her body. It's also weeping through the skin. I noticed she has bumblefoot between her toes as well, so that will need to be taken care of, but it isn't bothering her right now. I'd like to try to save her, and I have penicillin on hand. How much of a dosage should I give her to really try to knock this infection out of her? How often should I give it to her?