Look at the eye. It appears it may be this hen has Marek's and is exhibiting the ocular form of it. Look at her feather follicles. are they raised and bumpy?
Marek's symptoms can manifest at any age. I would send her body off to a lab for a necropsy when she dies. You need to know if it's in your flock.
Marek's symptoms can manifest at any age. I would send her body off to a lab for a necropsy when she dies. You need to know if it's in your flock.