We currently have 4 brown shavers & 4 silver lace wyandotts. All stopped laying over four months ago. They have an auto feeder & waterer. I clean out their poop every day. I change their water weekly. They have peck n lay & daily scraps. They have hay & wood shavings in their generous coop. We've become a rehoming station so I'm not sure the ages of the chickens. The wyandotts appear in good health but the shavers look straggly & are dying one by one. My husband thinks they may have mites on their legs. There is a runny poop or two the coop daily. It starts with their general appearance deteriorating & malting then their crown goes floppy.I have found three over the past three months dead in the coop. Now another chook is following suit & she is limping too. I'm not sure what could be wrong. What can we do???