I am slowly loosing my flock of chickens....2 months ago chicken pox went through my flock, with some of them getting the really nasty kind that caused growths-sores inside their mouths, I lost 3 nice hens to this. Now I am getting a sick chicken about once every month or so, the hen will be listless, stop eating, just stand around with no sign of sickness on the combs or eyes. They just kinda whither away slowly for 5-7 days until they die. I have tried every kind of treatment I can think of, I have injected baytril, genomacin, tylan, you name it and I have tried it....even sulmat in the water, nothing helps. I have wormed them with ivecmectin too. These are pullets that are laying, I feed a mixture of dried cat food, 16 percent layer and I even throw in a little rabbit pellets...could it be something that I am adding in their diet?