Hi, our 3 year old Rhode Island Red hen had diarrhea for several days, and today when catching and examining them for monthly dusting, I saw the vent is blackened and open—it looks like I can see innards! She’s been eating and drinking, but not hanging out with the others. Uggg… is there anything I can do, or should we just let her go? Her eggs had thin shells for the the last year or so, and they always have access to oyster shell