Black runny poo and no eggs

[The Duck Dad]

So, my 7 month hen has black super runny poop, she is outside all day eating stuff. all of her sisters are laying, but not her. i think it started when i had the ducks in with the chickens. she's on corid, but it doesn't seem to do anything. all of her sisters are fine and laying but not her. she's still active and seems normal otherwise. i'm not really worried about the black color, but of the runnyness and her not laying eggs

 

[Banana01]

So, my 7 month hen has black super runny poop, she is outside all day eating stuff. all of her sisters are laying, but not her. i think it started when i had the ducks in with the chickens. she's on corid, but it doesn't seem to do anything. all of her sisters are fine and laying but not her. she's still active and seems normal otherwise. i'm not really worried about the black color, but of the runnyness and her not laying eggs

There are some chronic illnesses where black diarreah is a symptom. I have had a similar hen that had this. She also had red rashes on her neck, she was a naked neck turken. She also twitches a lot. Eventually the illness went dorment and she layed eggs again. If she does have a chronic illness, hopefully it will pass for you, but from what I remember it was for life. None of my other 25 or so adult hens ever caught the same thing despite sharing food and water. She is one of my oldest too, and still twitches and has rashes, but plenty of blue eggs.