Sick hen- limping, poopy butt, stretching her neck and opening her mouth. Losing feathers across her breast. New to chickens, help!

[Sed78]

I’ve got a nearly one year old laying hen -Noiran- who has been acting strangely for the last 7 days or so.
She started limping, and I thought maybe she just had a mild injury so we kept an eye on her. She’s now barely exiting the coop, still limping, her breast is bald, and now she’s stretching her neck and opening her mouth like she’s gasping but there’s no gasping noises or anything.
She still seems to have an appetite. Her crop was palpable but not hard. She has been prone to a bit of poopy butt, so I gave her a little soak in Epsom salts yesterday (also hoping if her leg is injured it would help), but I didn’t notice any obvious wounds or other injuries.
Her comb also looks sort of shrivelled and blackened on one end and now I can’t remember what it looked like before!
Any advice? I don’t know where to start!

 

[Sed78]

I’ve got a nearly one year old laying hen who has been acting strangely for the last 7 days or so.
She started limping, and I thought maybe she just had a mild injury so we kept an eye on her. She’s now barely exiting the coop, still limping, her breast is bald, and now she’s stretching her neck and opening her mouth like she’s gasping but there’s no gasping noises or anything.
She still seems to have an appetite. She has been prone to a bit of poopy butt, so I gave her a little soak in Epsom salts yesterday (also hoping if her leg is injured it would help), but I didn’t notice any obvious wounds or other injuries.
Her comb also looks sort of shrivelled and blackened on one end and now I can’t remember what it looked like before!
Any advice? I don’t know where to start!

**Also want to say, I wouldn’t normally have left it so long but we had a family emergency that took precedence unfortunately so just getting to the hen, now.