Sick chicken

[pandabunny26]

This is Dixie, our Mille fleur bantam. She's our sweetest chicken, runs up to you for pets like a puppy. We've had her since 2015, we got her from some friends and we figure she's at least 8 or 9 years old. She's never had any problems. I came out this morning and immediately noticed something was off. She didn't come up to me, and stayed where she was standing under some hay bales. She was acting lethargic and almost felt lighter when I picked her up. Her tail was drooped and she was seizing repeatedly like she was going to throw up. Her crop has been very soft all day. We brought her in and fed her some nut snacks and she perked up afterwards, and seemed fine for a while. I checked on her again later and she was fine. "fuller", I guess, and running up to me. Came out again just now, and she seemed sicker than ever. Once she stopped seizing, she perked up again and was fine. Now she's sitting on my lap, still acting a little slow. I am aware that she is 8+ years old, but these aren't symptoms I have seen much in dying chickens before and if there's anything I can do, I want to try and help her. Her comb is still bright red, I haven't seen her poop or actually throw up yet but her crop keeps emptying and filling up again whenever I check her. Any advice or ideas are appreciated.
Also, I haven't read up much on sour crop and don't know if these are the symptoms, but I plan on checking her crop tomorrow morning and I can update then.

 

[Yah]

I had a chicken throw up they other day and then ran around like nothing ever happened

 

[Yah]

also she's adorable

 

[Eggcessive]

Sorry about your hen. She looks just like my Millie that lived for 10 years being just like yours. She suddenly developed ascites and pressure in her lower abdomen, then died within 2-3 weeks. She has some water filled cysts inside her belly when I opened her up.

When you say she was seizing, did you mean that she was gagging or adjusting her crop with circular neck movements? How does her crop feel—empty, full, soft and puffy, doughy, or firm? Can you check it first thing in the morning before she has anything to eat or drink, and tell us how it feels? Do not feed her any nuts or whole grains if you think she has a crop problem. If her crop is full in the morning, smell her breath. Offer fluids and a little watery feed.