She is my favourite, the clever one out of the group. She has had a darker comb for a while-initially the vet thought it was gape worm, so we wormed the flock (4 altogether). But no improvement, in fact her comb is darker and she is slower than usual. She went back to the vet on Monday evening and the vet thinks now it is a respiratory thing of some sort, but probably not micoplasma as it isn't "wet". She is now on antibiotics and separate from the others in the day. She looks slightly worse today, but she's only had one full day of antibiotics so too soon to take her back to the vet I suppose? She is eating things she loves, like mealworms, and laid an egg yesterday, but had a big fright the night before when a fox was trying to get her (she is in a large dog crate next to the others' run, foxy was trying to bite her through the bars and she cut her comb a bit jumping about). She just looks less bustly generally and is a lot slower on her feet as she is breathless. No discharge from her nostrils, I can't hear her wheezing, and she isn't gaping but her chest is rising more than normal when she breathes. Anything else we can do? Anything it could be that vet might not have thought of? (we live in a farming area so sick hens tend to just get despatched, not taken to the vet). She is 4 btw. And aside from me loving her, my dds have had a year full of illness and death (my Dad and others) and will be really upset if anything happens to her.