Hello.... 3 year old black star is sick for the 2nd time in 2 months for about 1+ week now. She exhibited the same symptoms about 4 weeks ago but improved on her own. For about 3-4+ weeks she has been having watery green poops. The entire flock (4 birds total) have been having some watery poops since July. I attributed this to the heat as all of their activity levels & appetites were very good when the watery poop started; checked the poop chart and thought it was ok. Now the little black one has become reclusive and lethargic, losing her appetite and losing weight. Vent looks dirty. She is not egg bound. No respiritory symptoms, no discharge from the eyes, no loss of balance/staggering . She has not laid for about 3 weeks (hard to say exact timing on this). She has not stopped eating and drinking completely but she is no where near her normal stamina. She and all the other birds still have watery poop as well but it is not hot anymore. I now believe I have to treat them all to prevent them all from declining. I gave them all pedialyte since saturday as well as poly-vi-sol baby vitamins in a mash of blue seal pellet feed, scrambled egg with the shell and olive oil. All the birds loved the mash except the sick one. She drank the electrolytes but her appetite is very sluggish. Today she eagerly ate tomato and a little cracked corn. I use pine shavings for bedding. I've cleaned the entire coop and added DE to combat any lice or mites. (I noticed one of the other birds scratching herself yesterday but she is molting around her neck). The coop has an unusual odor....I would not say particularly foul but not normal. I've ordered de-worming medication from the local feed store. It will be in the day after tomorrow. I want to give the entire flock antibiotics as well. I am not sure what kind of illness to suspect here but I want to try to rule out bacterial infection by treating with a broad spectrum antibiotic. What should i use? Tetracycline? Where to get it? Thank you for any advice as to what she/they may have and how to treat it.