I am sorry to hear that you lost your chicken. I just lost mine two days ago, when I took her to the vet. She died on the exam table, in a seizure of some kind while they were holding her. She was also filled with fluid, she had ascites. It was pretty tragic to witness. And so sad, because I was taking her to the vet with hope that they could help her, and, in fact, they (accidentally) killed her.
I have read that handling a critically ill bird can push them over the edge and cause them to die. And I have read, that so could draining. I think any intervention for a bird that is just holding on could kill them.
Kathy/Casportpony just posted that a hen of hers died in her arms while she was draining her: (beware, very graphic pictures, but it made me feel better to see how bad egg yolk pertonitis is. It didnt matter if you drained all or half of the fluid, no bird would live through this
https://www.backyardchickens.com/t/...scites-and-eyp-very-graphic-necropsy-pictures
20 ounces doesnt sound like a lot, thats almost 600 ml, and I have regularly seen pictures of people draining 500, 550 ml. I will post the link if I can find it.
Its very painful to lose a beloved pet, I know! It seems to becoming less painful, and I seem to be letting go of some of the guilt. My friend said to me, "Her physical body took her as far as she could go."
Take care,
Allison