Help! Puffed up and lethargic chicken

[CluckmoreEstate]

Need help-I've read so many threads and can't seem to figure out what to do
I have a 6 year old Golden Comet, I did dewormer two weeks ago and I treat monthly with Corid

She's in the "ill chicken pose" puffed up, standing with her head pulled into her chest. Not eating or drinking, very lethargic, but still alert.
She's also been molting for the past couple weeks so I'm not sure if that's taking a toll on her- comb is still bright red.

I've been trying to give her yogurt and gave her a cc of vitamins this morning and last night- I wasn't sure if I should do Corid as well- but I've read you can't mix those?
She hasn't laid in months, her poop is watery and a bit green. She won't eat or drink on her own but will swallow if I use a syringe.

any advice is much appreciated!!

 

[Chickenchickwithchickens]

My thought would be Cocci, but since you are already treating with Corid that would be unlikely. Maybe since she's getting older she's more susceptible to other sicknesses. Try Corid again just in case. Hope she gets better!