I have an approx 10 wk old BA that this morning looked and acted less intrested in feeding. This evening when I got home she was not eating at all with the other chickens and was setting in the corner with her eyes closed I did pick her up, and by feel she feels normal weight the other chickens are ( 7-18 wk old production and 3-23 wk old BA's amd 3 that are her age) They are not picking on her I have spent the last two hours watching from a distance and they are all eating and scratching in their pen. This pullet is eating grower and ACV water 1 tsp/gal. I do give a treat every once in a while ie Yogurt. I dont see any wounds I have looked her over I did see some runny poo in the pen dont know from who. I would like to self treat. Should I give her Antibiotics? should I seperate her from the rest? they are in a 24X12 pen with a 12X10 roosting/laying area. I do have a large kennel (Dog) I could put her in.