I am getting very depressed about the state of my birds. Just when I thought the illnesses had passed, I have now lost a young pullet and about to lose a second. These four girls are about 12 weeks old, but they look more like 8 wks due to cocci off and on throughout their growing. I have had them on medicated feed for the last 2 weeks or so. I went out the other morning to find one girl limping around like one leg was paralyzed. I moved her and another one into the garage. Within 24 hours the limping one was dead. Now the second one is lame, barely able to walk. She is weak but still eats and drinks. There are no respiratory symptoms, but the vent feathers seem wet, although I watched them poop and it seemed normal, ?? She (and the one that died) seem pale in the face (and has looked like that since about 3 weeks old) I thought it was because she has white skin whereas the 4th chick has more yellow skin, but maybe it is part of the illness since the 4th girl is much stronger looking. I looked up info on Newcastle and other diseases and watched some videos. To me, it doesn't look like typical Newcastle - there is no twisting neck or head. No stargazing. Her face seems normal, other than closing her eyes and sleeping a lot. Yesterday she was standing up most of the day, now she's laying down on her feet. Does anyone have ideas? They were not vaccinated for anything. Arent they too old for Mareks to show up?