Improving circulation in large combed roo?

[Everose]

I was searching circulatory issues before starting a new thread and saw this one. wondering about updates on your birds?

I have a 2.5 yr old laying hen who is very lethargic, has battled bouts of that on and off the last year. Every few months she spends 2-3 days like she might die any minute, she recovers, in a few months it happens again.

Now her comb is unusually dark red/purple and lethargic. Makes me wonder if it is a heart/stroke issue. But 2 days later and she is still alive, still eating. My other 5 hens are just fine. At this point I don't know what to do for her. She is well taken care of, well fed etc.

My birds have never had such serious issues, I'd start a thread and see what the experts had to say.
My roo went to a new home a couple months ago, his comb actually looked much better once the weather warmed up.
Roos don't hide their heads under their wings like hens do, I think that was mostly his problem, but a hen with lethargy and a dark comb sounds more serious.