I have a 3mo old cuckcoo maran that has an on going sneeze(or cough) and now you can hear rail or a rasp when listening to it breath, also my other chickens have tried to peck it's left eye out twice. I have treated with powder teryamyacin(bad spelling) in the water it has not worked I would try something else if I knew what to use or what i'm treating. Are the other chickens attacking because it is sick? and is the cough(sneeze) pneumonia? None of my other chickens are sick. Any help or suggestions would be greatly appreciated.