Chickens eyes swelling shut , please help

[NRXTM]

I have about 200 chickens , I have had them for about 2 years. For the first year all of them were healthy and normal , but starting a few months ago they seem to be diseased. A few have been dying every week. The symptoms I see are the eyes swelling shut and they wont eat much resulting in weight loss, and some of them that are at least 4 months old, look like they are a few weeks old. I have tried most everything from the local feed store. Also I have lost a turkey from its face swelling up and finally dying and now I see that one of my guineas face is starting to swell up also. I really need help to get my chickens healthy again. Here are some pictures , thank you

 

[welasharon]

Could they possibly have blackhead?

 

[NRXTM]

No I don't think so, I looked up chicken blackhead and it shows that their livers having strange dots on them, my chickens livers look fine

 

[welasharon]

Does it smell bad? It looks like one I had with coryza...that first pic.

 

[NRXTM]

No , no odd oder but a few of the symptoms seem to match actually.