I just remembered, I read that Mareks incubation period is 4-12 weeks, so if my friend's chickens just came 3 weeks ago, that wouldn't be enough time for mareks to incubate. correct? and the silkies started showing symptoms only about 1 1/2 weeks after the new silkies.
Upon further examination, the silkie and the LF chicken neither has anythign weird going on with their eyes. they look good. neither are sneezing or anything. they both look good, I don't see mites or lice on either of them. the LF one does have some pecking on her back above her tail feathers, but that could be from Queen who mounts the chickens. I don't know.
The silkie has an empty crop. The one that just died also always had an empty crop, and got thin. this silikie is also getting thin and apparently isn't eating. would worms cause this?? I'm grasping at straws here. I'll be heading to the feed store this morning and I just am not sure what to get them.
Mareks takes a long time to show it's effects. I don't think that is what this is.
The symptoms sound like an overload of internal parasites to me. Some type of worm. I would get a faecal test done before deworming these birds though. No need to administer drugs if it is not needed.
Also - our agriculture department does free narcopsies. Maybe that is something to consider? You do have recently deceased birds you could submit for testing.