so about 1.5 months ago i noticed one of my chickens was starting to act really sick, (congested, sneezing, coughing). i have been giving them the antibiotics in their water ever since then and they are not getting any better. i change the water every day. all of the chickens are very active and they eat and drink like machines. when they are eating, you can hear the congestion. they will not get any better! most of my flock are in a pen together and most of them are sick which is why i havent tried to separate. i separated the one a month ago when i noticed but i guess it was too late as more than half are experiencing the same things. they are all around 7 months old except for one rooster, hes a year and a half. any help is greatly appreciated...i love these birds. no vet around my area has a clue and no one can help.