i have treated my whole flock with tetracycline for a week and they are still coughing. the watery eyes are a little better but they are very congested. it has been raining a lot here and i am sure these wet conditions arent helping. i have culled about 25 of the sickist so far. i really hate to cull my complete flock. 50 more will break my heart. some do not look or act sick and i am still getting about 15 eggs per day. what should i do and do you think the ones that are not sick will be ok?