Unusual pupils on my chickens, recently had a chicken lose mobility as well.

[Chad Duncan]

Several months ago I noticed that I had a chicken with what I will call 'crazy eyes', one pupil large and one pupil tiny. The bird didn't seemed bothered, so I wasn't overly bothered either.

A week or so ago one of my younger hens lost the use of both of her legs from the knee down overnight. I put her in quarantine, and started googling potential problems. Marek's seemed a possibility and when she was no longer able to get to her food dish I euthanized her. Seeing that one sign of mareks is a messy pupil I started looking closer at the chicken with the crazy eyes, and saw a gray halo around the pupil. Then I went to my other coop and found another chicken with 'crazy eyes'. And a gray halo.

I took a couple of pictures and I'll submit them to you for your opinions on what may or may not be going on here.

Here is a normal eye from one of the birds:




And here is the crazy eye from the same bird:



And the crazy eye from the second bird:



What do you think? Do I have marek's running through both of my flocks?

 

[QueenMisha]

My flock runs Marek's, as does one of my friend's, and I've seen these kinds of eyes a few times in both our flocks.

How did the immobilized bird look, exactly? Was it kinda like she was doing the splits, with one leg straight to the back and one leg straight to the front, or similar to that? Are your birds vaccinated?

I want you to check each of your bird's necks, right along the spinal column. Look/feel for small, flat, pancake-shaped lumps. A mild strain of Marek's, such as mine, frequently causes these "pancake tumors" to pile up on the neck and spine. They aren't dangeorus, but helpful for diagnosing. You should also perform an autopsy on any further birds who die or are culled (regardless of the reason - even if you lose one to a predator attack, etc., you should take the opportunity to see what's going on inside).

The Great Big Giant Marek's Disease FAQ is an excellent resource for learning about this disease.

 

[Chad Duncan]

How did the immobilized bird look, exactly? Was it kinda like she was doing the splits, with one leg straight to the back and one leg straight to the front, or similar to that? Are your birds vaccinated?

Both legs were generally forward, I guess. She had use of them from the knee up and could move around by walking on her knees. I tried tickling her feet but got no response.
I refer to them as 'my birds' but they really aren't. I am co-owner of a farm and pay more attention to them then the actual owner does. I'll inquire about vaccination.

 

[Chad Duncan]

The chickens have not been vaccinated.

 

[QueenMisha]

Then it sounds like Marek's to me. An autopsy would help prove it but if you keep seeing symptoms it can be concluded as a likely cause. Luckily, it also sounds like it's a mild strain - being unvaccinated, an aggressive strain would typically result in far more loss. (Though this varies by age, breed, and quality).

This still means that for the foreseeable future or until it can be conclusively proven not to be Marek's, you need to quarantine your entire flock. Although a mild strain won't do much physical harm even if it spreads, it can be very bad to those who have large flocks or who sell their birds - they will have to cease selling operations and/or expect loss - for example, a 5% loss may not be a huge deal or even noticeable in a 10 bird flock, but in a 500 bird flock it becomes a definite issue. And, of course, a 100% loss in sales due to a cease in operations is definitely gonna be a bad thing. So this means no birds can leave the property - no swaps, shows, auctions, or rehoming/selling of birds for any reason (even if the bird did not show symptoms, it still most likely carries and transmits the disease). Birds can be brought into the flock, but you must be aware that there is a chance they will succumb to the issue and accept this as a risk. Do not wear shoes you've worn into the coop into feed stores or other areas where chicken owners might frequent. If you've been handling a lot of birds or doing a lot of work in the coop, change your clothes before going anywhere off the property. Eggs and meat of infected birds can still be consumed, and the birds are still 100% safe to handle, as Marek's cannot effect humans.