One of my hens had a very dirty vent, matted down with brown poop. I set her in a warm bathtub thinking that perhaps she was constipated, but after she was in there a few minutes, I noticed two groups of what appeared to be worms beneath the water. They were very short, thin and brown. Were they worms or mites? She passed away yesterday. Please help! I don't know if I should get a wormer for the the rest of the flock or an antibiotic! I purchase Walzine, but how can I give a dose to a flock of only 15 chickens? And when can we eat the eggs again?