Pullets going blind

[scoutmc]

Hi y'all,

I've had chickens for over 10 years and have never come across this issue with them. At the moment we have too many chickens, around 70ish + some new ones a couple of broody hens have been popping out - but my issue is with TWO 4-month-old Mystic Maran pullets. We ordered them in a large batch of chicks from an online hatchery back in March, and until now, we have had zero issues with them.

They have a 3-4 acre fenced pasture/wooded area (shared with an LGD and some sheep) and a large chicken coop, and their diets consist of whatever bugs they find, free-choice organic laying pellets, and clabbered milk (given almost every day). Nothing has changed in our routine with them. I can't tell if this is some sort of deficiency or a possible injury, but I feel like it's not a coincidence since there are two of them with it.

The first one started acting strange a couple of days ago, and today all she wants to do is sit and sleep. Her eyes are very cloudy and I'm 99% sure she can't see much, if anything. She keeps her eyes closed most of the time, isn't eating but I've gotten her to drink. The second one started acting strange today as well, and her eyes look cloudy but not as severe as the first one, because she can still see enough to eat.
If anyone has any possible clues as to what is wrong, I would be very appreciative! I hate seeing these poor girls suffer.

 

[Eggcessive]

It is hard to see the pupil shape and iris color in the photos. I hate to ask if you could get some clearer pictures without light reflexion in the eyes, but that may be needed. Is there any irregular shape of the pupils? Any dulling of the color of the irises? Is there any white or opaque patches on the eyes? How is the air circulation inside their coop? Any ammonia odors? The most common reasons for eye problems or blindness in chickens are vitamin A deficiency, past exposure as baby chicks to avian encephalomyelitis (epidemic tremors,) Mareks disease, ammonia burns from fumes from droppings, peck wound or injuries, cataracts, or eye infections. When chickens become blind, many times they can still tell shapes of things, dark and light, and can find their way around a familiar coop.

 

[scoutmc]

The coop has good ventilation, it has windows on 3 sides that are open almost 24/7 unless it is rainy. We also clean it frequently so I don't think ammonia is the issue.

I was thinking possibly Marek's disease (we did have a few chickens that were crippled with it many, many years ago), but other than their cloudy eyes they have no other symptoms of it. No lameness, they walk just fine but the blinder one chooses not to walk.

Their eyes seem completely normal, just cloudy. Pupils look normal but not sure about the irises or opaque patches. I will take better pics of their eyes tomorrow morning though, and take some pics of our other same-age Mystic Marans for comparison.

Is there a certain way to give them vitamin A and/or type? I think I have the powdered form that we've used to administer to cattle.
Also- if they have avian encephalomyelitis is there a treatment? I have researched that and cannot seem to find a cure, only that I just have to wait it out.

 

[Eggcessive]

If they are getting a balanced diet they should be getting enough vitamin A. A is one of the fat soluble vitamins and can be overdosed, so giving it in a vitamin probably is not a good thing. Here is a list of foods rich in A:
https://www.healthline.com/nutrition/foods-high-in-vitamin-a

There is no cure for avian encephalomyelitis. It is mostly a disease of baby chicks, but if birds recover, cataracts can be a result. Those cause a cloudy appearance, but the pupils are round although may be large or dilated.

Mareks (the ocular form) causes a grey colored, not clouded eye. It can be the only type you see, although they can have ocular plus other types. The pupil usually is irregular shaped, not round, and may be smaller. Here are some photos of Mareks, and at bottom the right eye is Mareks.

 

[scoutmc]

I tried my best to get some pics today, but nothing I took accurately shows their eyes.

I did study their eyes and I am positive that (aside from being clouded over) they are completely normal - nothing like those pics you posted above of ocular Marek's. Irises and pupils are normal looking and normal shaped, no opaque/white patches. Just cloudiness! But they both can definitely at least make out shapes. The larger one is doing great today, still sleeping more than normal and closing her eyes a lot, but she has energy and is eating and drinking perfectly. The sicker and smaller one has lost a lot of weight and keeps her eyes closed most of the time. Refusing to eat.