Unhealthy hen went from bloated to skinny

[Sara9]

I have a black hen about 3 1/2 who does't appear to have laid in a while. For a week or more her rear end below her vent was bloated and pretty big. She doesn't have feathers under hear tail so it was pretty apparent and the skin is reddish...but like the skin on my other hens who are missing feathers. So she looked big and bloated and was pretty slow and didn't do much or move around much but otherwise was okay. Now her rear end is almost deflated looking and the skin isn't taught but wrinkly and she just feels smaller and super skinny. Thoughts? Is it cocccidiosis? internal parasites? My other 10 birds don't seem bad off, what should i look for or treat?
Thanks!

 

[casportpony]

Look up ascites and see if it seems like that.

-Kathy

 

[Sara9]

It is posible that that is what it was, because she was very bloated like that, although her comb had looked okay so she didn't seem too sick in the way the internet described and she has lived in pretty good conditions so I'm not sure how she would have developed that.
The thing is that now she is not that way, and is very skinny and gaunt in the rear, and the skin looks 'sickly' because around the reddish skin her normal skin is yellow tinted. Her 'pelvic' bones also protrude more than i have seen in other birds and she is very light weight now. It is almost like something was in her and now isn't but she isn't covered in anything and I haven't seen anything unusual around the coop.
Any other thoughts? Should I still be worried? Parasites maybe, I haven't treated or tested for that before?
Thanks so much!

 

[casportpony]

If she were mine I would worm her with Safeguard liquid for goats or Safeguard paste for horses. The amount I've been giving lately is .5ml per 2.2 pounds for 5 days (50mg/kg).

-Kathy