I have a hen in a similar state. I have seen this before, and it's rarely ever good news, unfortunately. The only two hens I've lost (an Australorp and a Golden Comet) passed of salpingitis and cancer, respectively. I don't think it's Marek's based on my experiences, but I'm not an expert. I bet she's lost a lot of weight rapidly. I would def try vitamins or mash to get her eating again.
Oh - you might bring her inside overnight and withhold her food to see if her crop is emptying well overnight. That can help determine if a crop issue is involved, too.
Oh - you might bring her inside overnight and withhold her food to see if her crop is emptying well overnight. That can help determine if a crop issue is involved, too.
