Last week I had a hen with a wound on the base of its tail. I separated this bird and dressed its wound with Blue-Kote gave it a couple of days, the other just started in again pecking at it. I separted it again and then this morning I now have four out of six bleeding and being pecked. All now all around its vent, one is so bad I separated her and she just stands there??? They have been in their coop and run area since June with no problems, now comlpete melt down??? They are Red Sexlinks, still got six eggs this morning and have been getting six every day for the last two weeks! Coop is 4'x 6' and run is appox. 80 sq, ft. The only thing different since the begining is I added some Apple Cider Vinegar, 3 tbsp to 3 gal.??? I had chicken before and have never experience anything like this?Any advice would be greatly appreciated.