So I had to bring my dog to the vet today and while I was there I asked about the situation with my chickens. He said to give them the Tylan for 3 weeks. It's either going to work or it's not. I didn't ask about long term-- he didn't say. He lectured me on always quarantining new chickens first for a month. He said no more chickens come in--- this is it for us right now. We are at our limit anyway. He also said to put them on medicated feed. I was under the assumption that was just for chicks?? And he said (he would) eat the eggs during this time also (not so sure I'm going to do that). I told him that my neighbor was giving me the 50/50 mix of the garamycin and tylan and he said either or-- that or just the tylan. Since the feed store only carries the Tylan, that's what I'll stick with.