A few weeks ago, a stray hen showed up in my yard. I have 18 chickens myself, I sort of think someone dumped her in my yard. Well, she's some kind of a mutt. I've never seen a hen like her before. But she is sick! She had poo stuck all on the bottom of her. I bathed her and isolated her for 3 weeks, introduced her to my flock (which are all vaccinated for mareks and bronchitis) and now I think she's getting worse all of a sudden with watery poo, and she's sort of lethargic. Is there anything I can do to help her and more importantly, keep the rest of my flock from getting whatever she has?! Ugh.