Sicilian buttercup found dead

[neithardt]

Found our SBC dead this morning in the run. Saw her last around 2:00 yesterday afternoon, she seemed fine. No sign of predator, other two hens with her are fine. She started laying last July and stopped laying around October when we added a couple of pullets to her coop (she was separated from the main flock because they were bloodying her up pretty bad), so we added 2 pullets to winter with her. The other hens have been laying very consistently since reaching maturity. She was at the top of the pecking order to boot.
Just up and died, other hens appear fine.
Any thoughts?

 

[SunHwaKwon]

Found our SBC dead this morning in the run. Saw her last around 2:00 yesterday afternoon, she seemed fine. No sign of predator, other two hens with her are fine. She started laying last July and stopped laying around October when we added a couple of pullets to her coop (she was separated from the main flock because they were bloodying her up pretty bad), so we added 2 pullets to winter with her. The other hens have been laying very consistently since reaching maturity. She was at the top of the pecking order to boot.
Just up and died, other hens appear fine.
Any thoughts?

I had a similar incident with a pullet that died two days ago, though she had only stopped laying for about 2 weeks. I had a necropsy done (my state lab is very conveniently located, which helps a lot) and it was egg yolk peritonitis.