I'm new to chickens this year and have already had to treat them for coccidiosis and lice. I'm sick of scrambling at the last minute to go to the store to get the correct medication for them. I want to have things on hand here that they may need. What are the most common sicknesses? What medication do you recommend, what is it used for, and how do you use it? For example, what should I have on hand for a respitory infection? Thanks!