One of my black copper Marans, (her name is Copper), is suddenly unable to walk properly and I cant work out what is wrong. She is about 1 years old and previously in good health. She was broody for about a week until a couple of days ago. Last night when I checked the chickens and Copper was sitting on her perch as normal, but this morning when I went to feed them, she was stumbling around and flapping. I immediately separated her and washed her legs. I cant see anything obviously wrong. I am familiar with scaly leg mite and dont think she has that (no raised scales etc) She is eating fine but her breathing is perhaps a bit laboured. Her feathers are a little ruffled but she is alert and her comb is bright. She also laid a normal egg this afternoon. Her poo is normal too. We live in Southern California and the weather has been dry but not too hot. Its desperate to see her flapping about, unable to stand almost. I'd really appreciate your thoughts could it be the dreaded Mareks?