one of our 13 chickens (she is two and a half) has had a deep red/purple comb for two weeks now. she labors to breath - raspy. she eats, drinks, free ranges still. but walks slowly and rests alot. we did antibiotic water for 6 days. we didn't see improvement or more decline in health. i checked for mites. dont see any. now making apple cidar vinegar water for flock. rest all seem healthy and no sign of getting sick too. she also has shiny silver color on ears. I think respiratory infection or heart condition....but not sure. any ideas and help is appreciated. we feel bad shes fells bad want to help her feel better, but we don't do vet for a chicken (please don't judge on that part) thanks much!