Before I start, I apologize about asking questions that I'm pretty sure have been asked a thousand times, but please be patient. Last weekend I got 9 new pullets. I immediately quarantined them in a separate pen, but apparently not well enough, as my layers who are pasture raised and 100% free roamers developed coughing, sneezing and rattling within 3 days. (Possibly, I carried the sickness on my clothing or shoes and spread to my other chickens?) My vet charges an arm and a leg when you walk in the door, and so treatment is going to have to be by me. From all of the discussions, I am "thinking" that my chickens need Tylan, as it is a broad spectrum antibiotic? I am also thinking that for the next 4 weeks I will not be able to farmer's market my eggs. Rather than injecting, I am really looking for something that is soluble in their drinking water. I need advice from you all, as I want to take care of them right away. Thank you so much in advance. P.S. Strangely, none of the new pullets have any symptoms.