Sickly chicken

[Logjump]

Hi everyone, really really would appreciate some advice with our sickly lady. She's a 2 year old rescue hen who went lame a month or so ago randomly and was then given some Tylan 50 antibiotics off the vets, which we had to mix in the water for her drink. She improved but stopped laying (having previously laid daily from day dot). Then she started to lay eggs with no shells whatsoever, then eggs with just the membrane around them and finally last week started laying normally again. 2 days after this she became noticeably slower in her movements and very withdrawn. We saw she looked really puffy around her crop and then discovered she had sour crop. Took her to the vets again who made her sick and gave her another injection of antibiotics (not the same ones as last time). We then isolated her and gave her access to water only. Next day she was still puffy and not eating or interested in food. Took her back to the vets who made her sick again and this time it seemed like the got it all out. No more antibiotics as they were worried that had upset the gut bacteria. Gave her water (she was really thirsty) and a little mashed pellet, as she'd barely eaten for a few days. She seemed a lot brighter so the next morning we took her back to be with the other girls. Since then she's been out and about at times but mainly hiding at the back of the coop, trying to eat but sort of half heartedly picking at bits, only really taking water from our hands and not wanting to be with the others. We've given her Apple cider vinegar for 5 days and her crop doesn't feel bloated or impacted. We let them all out today and while the others were scratching, she just hid under some bushes and ate nothing. We've dusted her for mites and checked for thrush, her eyes are bright and her comb seems fine. Really worried that she's not eating and drinking enough. Have no idea what to do with her but she's very much not right and we're stumped at how to help! Any suggestions gratefully received.

 

[Shadrach]

Unfortunately crop disorders are often symptomatic of reproductive disorders.
This would seem likely for a ex battery hen. The high intensity egg laying breeds seem very prone to such ailments.
I'm afraid it gets worse. If your hen is suffering from say egg peritonitis, or another reproductive disorder there isn't very much you can do apart from keep her as comfortable as possible and when she will no longer eat and drink on her own, put her out of her misery as quickly and humanely as possible.
You can tube feed but it's really a temporary measure. Here's a good article on how to do it.
https://www.backyardchickens.com/ar...dications-to-all-poultry-and-waterfowl.73335/
I do hope I'm wrong.