I need some friendly advice: heres's the background to the scenario: I recently purchased two young millie cochins at a bird show at the beginning of May. I kept them separate for a while, but they ended up getting my entire flock sick with some sort of respiratory infection. Although, they themselves weren't showing the actual symptoms--I guess they had built up some immunity to it, they were carriers and brought the disease into my yard. I treated my entire flock with Oxytetracycline soluble powder for 14 days and then followed with vitamins and electrolytes for 5-7 days.... The first 5 days of soluble powder were accompanied with Tylan 50 from tractor supply administered once daily orally. I had to keep a few inside under a light to keep them warm---I had a loss of 3 of 30 birds...sadly it was the roosters. After this tragedy---I brought the two cochins inside and kept them in a pen by themselves---they also were administered the oxytetracycline (14 days) and vitamins and Electrolytes...and I wormed them. I didn't give them tylan as they weren't showing the symptoms.... I did have one relapse of one bird in the flock outside, which I quickly noticed and kept her seperate and gave tylan for 5 days...shes good to go again... My question stems from this: "How long do I keep these birds in quarantine?" I'm nervous to let them out with the others... Is there a broad spectrum antibiotic better than oxytetracyline for chickens? I hope I wiped out any pathogens in their systems. I read that they are carriers for life, but their bodies build immunities to it..