Hi there! I am new to raising chickens. I currently have 4 11 week old mille fleurs. A few days ago I noticed that one of them was behaving a bit different. It was scratching and eating but looked like its neck was slightly retracted. I didn't think tooooo much of it because it was peaking off the ground. A few days later I noticed the this chick was still doing the same thing with its neck, wings looked droopy and that it didn't look as big as the others but seemed as though there was bulge above its breast. It was eating and drinking and it's vent was slightly poopy but I couldn't find evidence of runny poop anywhere. Unfortunately, I had to go to work but called my local farming supply store and they suggested maybe it was a crop issue. Last night I took her out of the run and discovered how incredibly thin she is and that her crop was full....however, she was eating and drinking all day. I fell terrible at how thin she is. I gave her some ACV in her water and some scrambled eggs with some olive oil. Her crop was a bit squishy but no smell. I did massage it and separated her from the rest. She pick at the eggs and drank normally. This morning had a really big poop....not runny - firm but long. Her crop is down but her neck is retracted (tucked in). Do you think it could be something else?