Symptoms: My barred rock has been "off" since Saturday evening when I noticed. She is very light/thin, her comb is gray and she is sleepy/tired/low energy. She does walk around a bit and has been seen eating & drinking a bit each day, but looks generally miserable and clearly isn't eating enough since she's so thin. I'm new to chickens, we've had them for one month. The other 3 are normal, happy, perky, curious girls, my BR seems to be the only one with an issue. I have seen no stools that made me worry. No bloody stools, nothing abnormal. Spoke to a vet today on the phone, he said she is anemic based on her comb color. He worried about coccidosis. I went to our local feed store, which doesn't sell Corid, but gave me a Sulfa powder instead and he said to start that for a week. After doing some online research, I got worried about possible worms or mites, because they could drink her blood and cause anemia as well. I did a general "look over" and didn't see anything, but I'm far from an expert and I'm kind of nervous to dig through the feathers in her vent area, I just never seem to locate the vent. I think I should treat for mites just in case, it can't hurt right? I'm going to use Sevin dust on all of them tonight and clean the coop deeply tomorrow when its warmer & sunny so it has time to dry before they go into it for the night (too late to do that today). I ordered some Equimax de-wormer online, should be here later this week-- but I've read it can be harmful to de-worm an already sick/weak bird. Should I wait on that? My worry is that she, being as sickly and thin as she is, may not have enough time left to wait it out until she is stronger, and if she has worms wouldn't it be better to treat her as opposed to letting them kill her? Or will the Sulfa powder be enough to keep the worms at bay for awhile? I'm so confused on how best to approach treating her. I would think that if it was coccidosis, this being day 4, the other hens would/should being showing symptoms by now right? Since they aren't showing signs, should I assume it's not coccidosis? Or can they come down with it later? I thought I read somewhere that coccidosis would be deadly within 4-7 days, and this is day 4, but I guess that isn't a comment on how fast it spreads. If you were dealing with a sickly, weak, thin, anemic bird, and you don't know if its coccidosis or mites or worms or whatever...how would you treat?