I have been loosing a chicken every 1-2 weeks. I am not sure what it could be. The first one I lost back in November was a 16 wk old CCL pullet. No symptoms. The second was another CCL roo, same pen about a month later. No symptoms. The next one was a black copper maran, 16 wks, 2 weeks later. No symptoms. The next one was a 24 wk old columbian wyandotte roo from a different pen. He was lethargic the day before. I gave him probiotics and electrolytes when I found him. He also had runny green poo, would not eat or drink. He died the next day. A week after he died, another columbian wyandotte pullet, 24 weeks old from same pen starting acting strange. All she does is sits in one spot and shakes like she is shivering. Her comb is also pale but still red. I took her out the pen and put her by herself. I gave her oxytetraline, antibiotic, may have spelled wrong. Anyway, she is still alive but still shaking, she only moves to eat and drink. No runny green poo. Looks normal. Today, a 20 week old Americana, from a different pen was dead in the coop. I did notice last week she was moving slower than usual but she was eating, drinking, and roosting with the rest. I am at a loss. I have no idea what is going on. I have inspected all dead birds along with the one still sick. No bugs, no discharge from eyes or nose, no bloody poo, not noticing any worms in poo from coops. This last one must have just died, she was still warm. She was kinda thin in my opinion, and I did notice a bluish green pocket of something on her right side under her skin. Please help, I rally don't know how many more losses I can take.