Sick Guinea Keet, help!!

[Sulfate]

We have a little flock of Guinea Keets and I just noticed that one of them isn't feeling well. It has a long piece of plant life sticking out of its butt and the other Keets were pecking at it and pulling on it. It doesn't seem to be able to poop the rest of it out. It's acting very lethargic and isn't moving around much. It's just standing in place with it's eyes closed. When it does walk around, it seems dizzy or disoriented. What should I do?

 

[guineas in Maine]

Did you or anybody else ever find a cause or solution? I seem to be facing the same.
Also with head bobbing up and down like it's falling asleep at the wheel, and too heavy to hold up. It was fine the first week. Hardy and strong and loud and fast. Now this is out of the blue. This is my first time hatching. I have raised guineas from 2 day old before, first time seeing this.
please help.