Is it Mareks?

[Artichoke Lover]

I discovered that one of my roosters has an very oddly shaped pupil today and upon doing some googling Mareks is the only thing that is coming up..... None of my flock is currently showing classic symptoms of unsteadiness or weightloss but about half are not vaccinated. They are all between 9-21 months of age. No new birds have been introduced the younger birds are the offspring of the older group and they have not had contact with other poultry.
Edit: I don’t know how relevant it is but it expands and contracts normally with light and he doesn’t appear to have any vision problems.

 

[Artichoke Lover]

First picture is the oddly shaped pupil the second is the normal one on the other side.

 

[Lacy Duckwing]

@Wyorp Rock @Eggcessive @aart

 

[Eggcessive]

This could be a keyhole pupil also know as a coloboma, which is a birth defect in birds, and even in humans. The ocular form of Mareks can cause an irregular shaped pupil as well, but the colored iris will fade to grey. I would just keep checking it from time to time, looking at the color, and checking to see if he can see well. Here is a thread to read with more examples and some links to articles to read:
https://www.backyardchickens.com/threads/keyhole-cats-eye-pupil-ocular-mareks.856189/

 

[Artichoke Lover]

This could be a keyhole pupil also know as a coloboma, which is a birth defect in birds, and even in humans. The ocular form of Mareks can cause an irregular shaped pupil as well, but the colored iris will fade to grey. I would just keep checking it from time to time, looking at the color, and checking to see if he can see well. Here is a thread to read with more examples and some links to articles to read:
https://www.backyardchickens.com/threads/keyhole-cats-eye-pupil-ocular-mareks.856189/

If it was a birth defect would it be clear from hatch or could it have appeared later? I am confident I would noticed this fairly early on if it had been there before. Admittedly I’m not certain when it appeared as I’ve been ill quite a bit over the last few months and haven’t spent much time with my flock because of that.

 

[Artichoke Lover]

Is there a live test for Mareks and if so how would I go about finding out how to get one set off?

 

[JenBmomof3]

First picture is the oddly shaped pupil the second is the normal one on the other side.View attachment 2946793View attachment 2946794

I just got a chick with a similar situation. I’ve been trying to figure out what it is.

 

[Eggcessive]

If it was a birth defect would it be clear from hatch or could it have appeared later? I am confident I would noticed this fairly early on if it had been there before. Admittedly I’m not certain when it appeared as I’ve been ill quite a bit over the last few months and haven’t spent much time with my flock because of that.

Is there a live test for Mareks and if so how would I go about finding out how to get one set off?

Yes, the birth defect would be there in the beginning. There is a pcr blood test for Mareks disease done by a few labs in the US. Blood is obtained from a cut toenail and sent back in to the lab. Here is a link for the lab in Texas that does it, and you can contact them for info:
https://www.vetdna.com/application/forms/aviansubmittalform.pdf

How is your chicken looking now? Sorry that I did not see your later posts.

 

[Eggcessive]

I just got a chick with a similar situation. I’ve been trying to figure out what it is.

How old is your chicken? What does the other eye and color look like? Has your chicken suffered any injuries? If the other eye is not that color, I would wonder about possible ocular Mareks. I am no expert on Mareks or eyes, just an observer. Many chickens with ocular Mareks will develop a gray eye, and the pupil may be smaller and irregular. Here is more info:
https://ucanr.edu/sites/aves/files/336233.pdf

More pictures (normal eye in center)
https://partnersah.vet.cornell.edu/sites/default/files/avian_atlas_assets/MD-024A x750.jpg

 

[Artichoke Lover]

Yes, the birth defect would be there in the beginning. There is a pcr blood test for Mareks disease done by a few labs in the US. Blood is obtained from a cut toenail and sent back in to the lab. Here is a link for the lab in Texas that does it, and you can contact them for info:
https://www.vetdna.com/application/forms/aviansubmittalform.pdf

How is your chicken looking now? Sorry that I did not see your later posts.

Thank you for the link!
No change. The eye is still a normal color seems to have good vision and I haven’t seen any other symptoms in him or other members of the flock. It’s possible I missed it in the past but I’ll send out a blood test later in the spring to be sure.
He has a few other genetic quirks so I wouldn’t be surprised if it’s a birth defect and I just missed it somehow.