My largest and most dominant hen has suddenly lost a lot of weight and barely eats now, but my other two hens seem to be acting normal and have even started to peck on the sick one (she's never been one to put up with pecking). She'll eat a little from my hand and she did drink, but now she's sitting around sleeping. She used to start fights with my dogs and be very aggressive and entertaining...I really hope she isn't dying It looks like this may sound like worms, but I live in the city and have never treated for them before. She did have runny yellowish poop, but I didn't see any worms in it... (I'll post a pic). What should I do to treat for them now, and what should I do to help the sick one get healthy again? Also, I had been gone for a few days until yesterday while a neighbor was caring for the chickens, and I noticed the weird behavior when I got home. Everything went fine while I was gone, except I had gotten a new metal water dish for their run area, and I didn't make sure it was galvanized so it rusted while I was gone. Could the rust have caused this? The other two hens have showed no signs of illness, and they had the same water.... I have taken out the rusty dish. Thanks for any help!