So I noticed one of my buff blue Brahma pullets acting lethargic this morning and squawking this evening and not standing. However, she does move her legs and can stand some but seems off balance, with her head occasionally held low. Her crop is empty but I did notice some greenish poop on her vent feathers.She is a bit over 4 months old. Hoping this is not Marek's or something along that line. Any help is appreciated!