I found one of my chickens, Brown Leghorn, a young pullet, dead last night. There had been no signs of distress, she looked healthy before, with red comb and wattles. I opened her up this morning and discovered that she had an enlarged, yellowish liver, her other organs looked pretty abnormal as well. We happened to have slaughtered 4 other chickens, a couple of extra roosters from laying breeds and a couple of broiler hens, a day before, and they were all perfectly normal, with normal livers and other organs. Below are a few pictures from my autopsy. I hope someone is familiar with this issue. I don't know if it's anything I should be worried about in my other chickens.
Chicken died unexpectedly
Yellow or tan livers can sometimes be a result of fatty liver disease, but there can be many different causes of liver discoloration such as infectious diseases and heart failure. When livers that are discolored are discovered in processing plants, the carcasses are generally discarded. Here is some reading: