Hens not laying/losing feathers/pale combs

I'm not sure if all of these things are interrelated, however, here is the back story...

I have 6 hens, 5 standard, 1 silkie. They are about 8 months old. Two months ago all except the silkie stopped laying. Two of my hens were noticeably not doing well, and I noticed very bloody stool. The combination of the symptoms made me believe that the girls had coccidiosis. I treated with Corid, and they all improved, and have been behaving normally since. To date, they haven't started laying again. The silkie has since stopped laying because she's broody....go figure

I've noticed lately that the girls combs are paler than normal...not sickly looking pale, but just not as red. Three of the girls have noticeable feather loss, especially at their necks. One of them has feathers missing from below her vent. I checked them out last night and didn't see any red, irritated skin or signs of lice or mites. I did notice that some of the feathers seem to be growing back as well. There are a lot of feathers in the coop and the run, but also a lot of down feathers as well...which seems to be mostly in the run.

I haven't noticed any feather eating, picking at each other, etc. From what I've read, they are too young to be molting, so I am leaning towards it being lice and/or mites.

They do not get a lot of free range time, usually just an hour or two most days of the week. Their run is approximately 8' x 15' and their coop is approximately 8' x 7'.

It's kind of a tough time of year to tell exactly what it is because their laying would be slowing down, if not stopping, at this time of year anyway. So, I'm not sure if they are just molting at an early age, and the not laying because of the illness has just turned in to not laying because of the decreases daylight hours, or if they do have something going on.

Any thoughts?? This is my first time having chickens, so I'm not sure what to look for.

(Edited to correct spelling error)

 

Thank you both very much!