I recently took in a white pekin that is just a couple of months old. My friend has had problems w/ her dogs getting into her coop. She said about 3 days ago so went into the coop and this duck just sat there and would move. Long story short, his leg is lifeless and a little swollen but there are no visible marks on it. His wing, on the same side, has several scabs on it. He is eating, drinking, and enjoys the kiddie pool. But refuses to walk. I have an antibotic, terramycin, would this help?