I've never seen pictures of birds with pox like blisters all over its body... I've only seen on its head.Did you see all the pictures? Is there anything else that you know of that it could be? I live in Hockley Northwest of Houston. The ones that survived in my coop seem great now. All my research says that chickens exposed to the rest of nature (not isolated in a commercial facility are likely to get MG from wild birds and whatever diseases mosquitos bring.
Are you aware that you can send your next death to the state lab to get a necropsy to find out exactly what you're dealing with?