Lethargic hen

[Jamber]

I have a 1 1/2 year old hen, she looks like a leghorn but she lays green eggs. She has not been laying well the last few months, she's only laid a few eggs and the one she has laid are missing their shells. Other than that she seemed to be fine. The last few days however she has become lethargic, her comb is a light pink color instead of a nice red color. She will leave the coop but a lot of times she will just walk out and lay down in the grass. She has lost weight, I see no signs of mites/lice or bumblefoot or any worms. She is not sneezing or sneezing. Her eyes are clear. Her bum is curved. We did try giving her Epsom salt bath the other evening, I checked her vent to make sure she's not egg bound. we have provided vitamins and electrolytes, we hand feed her. I have done tons of research and have done everything I can to try to help her and figure out what's wrong and nothing is working. Does anyone have any idea what possibly could be wrong with this lady?

 

[Birdie mom]

She could have Egg Peritonitis?

https://vcahospitals.com/know-your-pet/egg-yolk-peritonitis-in-backyard-chickens