Ocular Marek's symptoms

aknewlin

In the Brooder
6 Years
Mar 23, 2013
62
9
33
I've been searching through old threads and information pages on this site about Ocular Marek's, and have learned a lot but haven't found out this bit of information yet.

I have an Easter Egger who is about 4 years old who is suddenly going blind. Both of her pupils have constricted and are not perfect circles anymore. The don't react to a flashlight and don't change size with light.

Like Marek's, her pupils are tiny and not perfectly round anymore (one is a little cat like, and the other a little amoeba like). Unlike Marek's, the iris color is still her original orange color and not gray/blue like Marek's. I've seen many pictures of Marek's eyes with gray iris.

Is it possible to have Marek's and still have the original orange iris color?

Other info: One of about 40 chickens, free range with feed always available. No other chickens showing any symptoms. This Easter Egger is now staying inside in a dog kennel, doesn't offer to come out of the kennel despite the door being open. She is eating (can see a tiny bit and can see food dish) and is drinking. Enthusiastic about treats. Poop looks normal. Isn't walking much, but suspect it's because of being nearly completely blind. Just coming off of a hard molt, so she hasn't laid an egg in about three months. Eyelids look normal. No limp, no sores, no wounds, no snotty nose or gurgling or anything other than sudden pupil constriction.

The coop is a bit overcrowded, and she normally sleeps on the top rung. My daughter "forgot" to clean the coop, so it was very poopy. I'm wondering if it isn't related to too much ammonia, but she doesn't have any other symptom of ammonia poisoning.

TL;DR: Does Ocular Marek's have to have a gray Iris to be Ocular Marek's, or should I be looking at something else?
 
Can you post pictures of your hen's eyes? I'm not sure that all eyes in ocular Mareks turn gray, nut I have seen pictures of pinpoint or irregular pupils in Mareks. The best pictures I have seen are on Cornell University's website Atlas of Avian Diseases, and enter Mareks in the disease name.
 
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I hope these pictures are clear enough. It's hard to get a picture of a moving chicken.

There is no change today. She is eating and drinking fine and has good body language. She's walking with a bit of shyness, I suppose because she can't see well. She appears to be a normal, healthy chicken with the exception of her eyes.

I have also found some info that I missed earlier in my reading: That the iris *MAY* turn gray, not that it will turn gray. sigh.
 
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So now my follow up question is:

If this is ocular mareks, can it present itself in a different way in the other chickens? Such as the paralysis and tumors? Or is it a specific strain of mareks that is solely ocular? We are keeping a close watch on the other chickens for anything odd.
 
Can you post pictures of your hen's eyes? I'm not sure that all eyes in ocular Mareks turn gray, nut I have seen pictures of pinpoint or irregular pupils in Mareks. The best pictures I have seen are on Cornell University's website Atlas of Avian Diseases, and enter Mareks in the disease name.
This hen had ocular and neural Marek's




Didn't necropsy this one, but pretty sure it's Marek's




Wingman has eyes like this and visceral Marek's


-Kathy
 
Follow up symptom.

Just now, she had a little bit of foam in the corners of her eyes.

Otherwise, a happy chicken with no swelling, gasping, or rattling. Walking perfectly normal. Eating, drinking, pooping.

I can't find anything (yet) that shows foaming eyes with Marek's. Any ideas?
 
She had the foam in her eyes for just that one minute, it was gone, and it hasn't returned. Mysterious chicken.
 
Foam in the eyes can be indicative of mycoplasma, but I have one hen who gets it on very cold mornings, then clears up during the warmer afternoons. She has no symptoms of a respiratory disease otherwise. Your pictures do look like ocular Mareks. As far as I know, chickens can have ocular Mareks without other symptoms. The 4 types of Mareks include the ocular type, the skin lesion type, the neuro type causing tumors on nerves, and the visceral type causing tumors on internal organs. Thanks to Kathy for including her pictures. Here are some good articles and threads on Mareks if you have not seen them, and have time to read them:
https://extension.unh.edu/resources/files/Resource000791_Rep813.pdf
https://www.backyardchickens.com/a/the-great-big-giant-mareks-disease-faq
https://www.backyardchickens.com/t/894589/moving-forward-breeding-for-resistance-to-mareks-disease
https://www.backyardchickens.com/t/741957/not-an-emergency-mareks-in-the-flock
 

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