Two days ago one of our roosters got his spur caught up in chicken wire and the outer shell tore off. We put antibiotic ointment on it and wrapped it up. We changed it yesterday and it looked fine, but today it looks swollen and there was a bit of green on the bandage. Do I need to give him an antibiotic, if so what? I need something that can be easily found at a feed store. I've never treated a chicken infection and would appreciate some help. Thanks!