Chicken's pupils aren't dilating

[NatureGirl74]

My 2 year old buff orpington's eyes aren't dilating. We checked the whole flock over last week and found that 1 eyenwas like this. Today we checked them again and both eyes were like that. She's getting around fine and doesn't seem blind. She's acting totally normal. I have one bird who hasn't had much energy lately and has a floppy comb, but she's mid molt and it's cold. Most of my birds act like that when they're molting. What's going on with this bird's eyes? Thank you in advance!

 

[Eggcessive]

It looks like possible ocular Mareks disease. Mareks can present in 4 ways—the eye form, the skin form, nerve form, and visceral tumors. Ocular Mareks can cause the pupil to be small and irregular shaped, and the colored iris becomes grey.

 

[MysteryChicken]

My 2 year old buff orpington's eyes aren't dilating. We checked the whole flock over last week and found that 1 eyenwas like this. Today we checked them again and both eyes were like that. She's getting around fine and doesn't seem blind. She's acting totally normal. I have one bird who hasn't had much energy lately and has a floppy comb, but she's mid molt and it's cold. Most of my birds act like that when they're molting. What's going on with this bird's eyes? Thank you in advance!

Looks like a classic case of Ocular Merek's Disease.

 

[Eggcessive]

Here are some links to read about Mareks disease:
http://csu-cvmbs.colostate.edu/Documents/vdl-mareks-disease-fact-sheet.pdf

https://www.backyardchickens.com/articles/the-great-big-giant-mareks-disease-faq.66077/

 

[CluckNDoodle]

Ocular mareks was my first thought as well but I see others have already chimed in.
Just know that it isn't necessarily a death sentence. Mereks can go unnoticed in a backyard flock sometimes without experiencing any losses. I've heard of people taking several different approaches to mareks. I know someone here on byc that lost some of her flock but kept the flock that survived it and only added vaccinated chicks afterwards. I also know those that decided to cull their entire flock and wait a year to start over.
Just know that they will always be carriers once they have it so at the very least, you'll want to avoid rehoming any of them even if they appear healthy they could easily infect others. I know this probably isn't the news you wanted to hear.

 

[NatureGirl74]

That's what I was afraid of. I got 13 chicks this summer. Thankfully they were all vaccinated. None of my older birds are vaccinated though. I have 13 older birds. I'm glad though that ocular mareks isn't usually as bad as some of the other strains.

 

[Eggcessive]

How old are the older birds? Did they come from a hatchery or feed store? Have you added any birds from other people in recent months, including the chicks? Or did they come from a hatchery?

 

[NatureGirl74]

How old are the older birds? Did they come from a hatchery or feed store? Have you added any birds from other people in recent months, including the chicks? Or did they come from a hatchery?

The older birds are 1½-2½ years old. The one with the weird pupils I got from a feed store. The 4 oldest of this group I got from a friend when they were 6 weeks old. I hatched the rest of the older birds. The chicks hatched on June 20 this summer. They came from a hatchery. I moved the chicks into the coop about 3 months ago. Before that, they lived with my peahen. The peafowl's pen is only about 1-2 feet away from the chicken run.

 

[NatureGirl74]

So far none of my other birds are showing symptoms. This one seemed to be getting better, but then her eyes got worse. They look horrible. One eye has an irregular pupil. The other was really dark, but not really gray. Now it's swollen shut. It was still open yesterday, but today she can't open it. Is that normal for Marek's? She's still acting normal.

 

[Eggcessive]

The right eye swollen shut is not normal, but some birds with Mareks will sometimes keep an eye closed on one side. Is she showing any weakness on that side? What does the eye look like if you open it? Can she see out of that (right) eye? It looks like she has been pecked on the comb and eye, which might have caused the swelling.