One of my chickens has been panting very heavily for the past week or so. At first I thought it was just from the heat, but now I’m starting to suspect that it’s something else because it’s not that hot today. When I pick her up, it gets even worse, like she’s struggling to breathe, and her comb turns a little blue. Any ideas of what this is? I’ve had chickens for 10+ years and haven’t had my chickens do this.