Old Hen

[roxanne]

Doesn't sound anything like Infectious Bronchitis or a respiratory disease.

6 is getting on in years for a Sexlink.
Do you feel any bloat or feeling of fluid in her abdomen?
Has she laid eggs recently?

A laying hen that is standing about, balled up with her eyes closed, gurgling is, ime, is having a hard time expelling an egg, is suffering from a reproductive disorder like Cancer, EYP, Internal Laying, etc., may have Ascites which is a symptom of fluid in the abdomen and/or is having some crop dysfunction as well.

I'd check her abdomen for bloat or fluid below the vent between her legs, make sure her crop is emptying. Do look her over for lice/mites while you are examining her.
If she's got bloat/fluid and/or swelling of the abdomen, sometimes fluid can be drained to offer supportive care and comfort - this is not a cure and sometimes this does not relieve symptoms and make a hen feel any better.
If she's been laying eggs and hasn't laid one, then I'd get some Calcium into her asap. This may help her push out any egg or material that's making her feel bad. 1 Calcium Citrate with D3 tablet daily for 1 week.

Gurgling and water coming form the beak is very likely the crop. (Sometimes gurgling is heard when a hen has fluid in the abdomen (Ascites) too).
If the crop is not emptying, then address that symptom, but very often a crop problem is going to accompany a reproductive disorder - inflammation, swelling, etc. in the body just slows the body's processes.
This is the methods I use to address the crop. https://www.backyardchickens.com/ar...w-to-know-which-one-youre-dealing-with.73607/

An antibiotic might help short term, but sometimes medication doesn't help at all. You can try something like Amoxicillin if you have it.

The antibiotic is part of supportive care and comfort for the hen, it's not going to be a cure either.
Unfortunately, these symptoms and problems seem to be very common in laying hen, I've had my share as have others.
It's up to you to determine how well she is, if she can bounce back for a while longer or if it's time to put her out of her misery.

Thank you so much for this information! I will definitely retain it for future use. Nothing was working to help this poor chicken and so my son helped me to cull her on Monday. It is sad, but it was much worse watching her suffer. I thanked her for all of the eggs she shared with me and my family and then laid her to rest.

This group is so helpful