Recently, my Dominique hen, Sweet, has started having runny yellow diarrhea. She is 3 1/2 years old and I have changed nothing in our coop recently. She seems to be eating and drinking fine. I just weighed her today and she is at 4 1/2 pounds. I'll record her weight in a few days. I'm gonna give her some vinegar and yogurt, and I will do some more yogurt. She seems that her vent feathers aren't really falling out and her crop is not swelling. What should I do?