Dilated pupils and off-balance hen

[Anaf]

Hi all! Last year I posted about my speckled sussex hen, Dulce, asking for your thoughts on why she isn't laying. She has still never laid an egg before and is about 2 years old now. Since I've had her, I noticed her pupils change size but given she didn't have any other issues, I assumed it was nothing to worry about. She is still in good health, eating and drinking fine and very talkative. However, in the past couple days I have noticed she likes to sit down more often and loses her balance at times. I have attached photos to show her pupils as they change size. I did some research and it seems I might be dealing with Marek's disease here. My other two hens are in perfect health and both laying. What are your thoughts?

 

[Eggcessive]

I think that Mareks disease might be a good possibility. The eye has a faded grey appearance and slightly irregular pupil seen in ocular Mareks. There is a $20 test on blood serum at UGA and this lab in Texas that is a pcr test for Mareks on a live bird:
http://www.vetdna.com/application/forms/aviansubmittalform.pdf
You can contact them or the Georgia lab to find out what you need to do. What is your location?
The other way most people can find out about Mareks is to get a necropsy on the chicken if you lose her or cull her. The state poultry lab is who to contact, and this list has mist of them:
https://www.metzerfarms.com/PoultryLabs.cfm

 

[Anaf]

I think that Mareks disease might be a good possibility. The eye has a faded grey appearance and slightly irregular pupil seen in ocular Mareks. There is a $20 test on blood serum at UGA and this lab in Texas that is a pcr test for Mareks on a live bird:
http://www.vetdna.com/application/forms/aviansubmittalform.pdf
You can contact them or the Georgia lab to find out what you need to do. What is your location?
The other way most people can find out about Mareks is to get a necropsy on the chicken if you lose her or cull her. The state poultry lab is who to contact, and this list has mist of them:
https://www.metzerfarms.com/PoultryLabs.cfm

Thank you for your reply! I am based in an urban area in New Zealand so don't have those same resources accessible to me. I wouldn't cull unless necessary as she is a pet. I assumed that given she has been living with the other hens for 2 years, if it were contagious, they would have contracted it by now. I can get a blood test at a specialised exotics vet (which will be a lot more than $20!) but just wanted to put the question out to you all first.