Autopsy advice needed - Mareks? Tumor?

[HENNIFUH]

Good afternoon, everyone! Newbie here with a question for you all. I have a large homestead and I am very experienced with raising and caring for chickens. However, I have found myself with a little issue here that is partially my fault as I should not have purchased these guys from Rural King to begin with. I usually buy from reputable hatcheries, but to be truthful, I had trouble saying no to clearanced chicks.. So, I bought many and as usual I am rather obsessed with their care and cleanliness. However, one by one, practically all suddenly got sick and died. Over 30 died, regardless of my aggressive efforts. The ones remaining have failed to thrive, often boney, underweight and small, and I have recently had two develop leg issues where they cannot stand. I am questioning Mareks and will have an official autopsy done on one. However, one died today randomly and it was one of the larger ones to have survived the sickness that killed the rest. No symptoms, just dead. When I opened her up, everything looked normal aside from this fleshy piece that I am wondering about. Is this a tumor? A fatty mass? What do you think? Forgive me if this is dumb.

 

[HENNIFUH]

Second image

 

[Banana01]

How old were the 30 that died? Other causes of mass casualty might be worms, cocci, viral or bacterial gastritis, anemia from poor diet.

There is a mareks blood test or im sure others will recommend state labs to send the dead.

How old was the one who died in the photos?

 

[HENNIFUH]

I treated them for coccidiosis as it is rampant here and they had all of the signs. They were weeks old, feathered. Most who survived just will not thrive, aside from a select few. The one who died last night was one of the remaining who seemed to be doing great, with no signs of anything being off. She was about 5 months old. Thank you

How old were the 30 that died? Other causes of mass casualty might be worms, cocci, viral or bacterial gastritis, anemia from poor diet.

There is a mareks blood test or im sure others will recommend state labs to send the dead.

How old was the one who died in the photos?

 

[Banana01]

Cocci treatment drains their thiamine levels, did you treat for 5 days, followed by how long did they live after the treatment?

If you suspect mareks the only way to be sure is a blood test and it costs around 20$ at a lab. I have never tested my animals, i dont know details, just that a mail in blood test will confirm it.

You could ask the seller if they are mareks vaccinated, although sounds like you wont trust them to know. Sorry this happened.