I have a mix of light Brahmas, Barred Rock and bantam de flure chickens they are about 3 months old. They started getting what looked like dried feed on top of their beeks, I tried to brush it off (but it was attached and was gonna bleed if i did), so i left it alone. Now they are lethargic and some have their eyes closed and are dieing, whats going on please help. What should i do and if i need to medicate please advise what Medication and what dosage please. Thanks.