Hello I want to ask for some help/advice about my rooster since Monday of last week his face and comb have started turning purple, and he has a had a loss in appetite, he has also recently started losing balance as well as has a sort if sore throat. is it a desease? An infection? And advice and help will greatly appreciated. Some things to note is he is 4 turning 5 on the 10th he is a Plymouth Rock chicken