Sick hen

[Bmxer883]

My oldest chicken 7-8 maybe 9 is looking rough she's starting to hunch and tonight looked like her breathing was hard. Typical I've noticed they die a few days after these symptoms.
Just wondering if there's anything I can do for her only thing i noticed is how nasty her feathers are by her butt

what causes that?

 

[Tonyroo]

That would be liquid poop accumulating on her back side. I suggest you soak her in warm soapy water and try to remove the material. There something causing her to be dehydrated hence why she's drinking more and her poop is runny?

When was the last time you dewormed her and checked for mites and lice?

 

[Bmxer883]

Be honest I've never dewormed any chickens before. We dewormer our sheep but never had issues with chickens. I didn't see any mice or lice.