3 of my Plymouth Rock hens have swollen buts and sores aroun vent
Watch them for feather picking which can lead to cannibalism. Too little protein in the diet, over crowding, boredom, and not getting out to free range may be a cause. Give at least 16% layer feed, and you can supplement with 24% game bird feed to increase the protein. Each chicken needs about 4 square feet of room in the coop, but they need to get out to roam. Watch for any bullies, and separate them. Blukote, Nustock cream, and anti peck lotions can help with red areas.