Can anyone help I've a chicken with a tail like this and lost one today

[creeny]

 

[ChickenCanoe]

Is she molting or does she have mites?

What happened to the one you lost?

 

[creeny]

They have been through the molt the other one her feathers were just growing back but her bottom was really red and swollen she was fine yesterday and this morning until I checked then at lunch and sadly she was dead ,

 

[creeny]

No we've checked for mites and no sign

 

[realsis]

I'm so sorry for your loss!!