As I have mentioned, my two older Sex-Links have passed away. Today, I found one of my Leghorns dead; and she was only one and a half years old. She seemed fine yesterday, but in the morning she was having trouble walking a bit. When I found her dead, I noticed that her comb seemed rather purple and swollen. What do you guys think? My other chickens seem fine, but I know that they can still have influenza without showing symptoms. I live in Minnesota, and all these deaths are freaking me out. Here's a pic of her comb. .