Newbie Worried About Her Hens

[andreanar]

Could certainly be Mareks. Look up what you can about the disease and see if that fits. And chickens don't usually show a sickness at first, you usually don't know until its too late.

 

[Wyorp Rock]

@Janey1129 Photos of your set up may be helpful.
What do you feed your girls?

Have you noticed any wet or moldy feed? Do your birds have access to compost piles or could they have gotten into anything rotten?

I agree that at their age, it could be Marek's - if you still have their bodies, sending them for necropsy for confirmation would be a very good idea.