Hi Guys, So normally I'm just a reader but this time I didn't see anything that could really help me. So I have 2 RIR 2 Barred Rock and 2 Black Sex links all 1 year old lay ed through the winter and still laying an egg a day from each.. So somehow I didn't notice till a few weeks ago probably due to the winter coming to an end, but my 2 Sex links have large bald patches below their vents, no bloody spots only one has a bruise where it looks like she pulled a feather and it left a little purplish spot (treated with vetericyn just in case) BUT Its only the 2 sex links. I have inspected for mites and lice also dusted everything heavily from the chickens and coop to the run in DE. I'm almost clueless as to what the cause is. Could it be a lack of calcium? I give them crushed egg shells about once or twice a month, does it need to be more? What other causes could it be? Keep in mind I only use natural treatments as I can. But the health of these girls is very important to me plus I have 1 month old silkies soon to be introduced so I need this cleared asap!