I'm sorry she is declining.
The liquid/water coming out of her beak sounds like a crop issue - she has a blockage somewhere. You report the crop is empty/flat, but she must be drinking(?) Crop issues can cause respiratory symptoms (gurgling/trouble breathing and sometimes wheezing) this would be due to possibly aspiration of liquids. Crop issues are often due to an underlying condition or illness like Coccidiosis or worm overload and internal laying/reproductive disorders. Inflammation in the intestines from Coccidiosis or worms can cause slow and/or block the digestive process making the crop stop functioning properly. Same with reproductive disorders - infection, egg masses/matter, tumors, cancer or fluid can block the internal organs creating stress and crop back up as well.
I've not seen any drug contradictions when using antibiotics with Amprolium, so generally speaking - it probably won't hurt. Depending on what you have access to - Penicillin is usually injectable and Amoxicillin is usually in tablet form so should not interfere with the intake of the Amprolium laced water. This is also to remind you as
@azygous mentioned - we are not vets and can only give you what information that we have common knowledge of - it's always best to consult you Veterinarian when giving any type of medication.
I will post the link for crop issues and treatment again, in case you missed it back on page 1 of this thread:
https://www.backyardchickens.com/ar...d-sour-crops-prevention-and-treatments.67194/
fwiw- Coccidiosis does not always present with bloody poop - if I remember correctly, there are only 1 or 2 strains that show as blood in the stool, the others (9total strains) present as loose stool most of the time with mucous. Accessing a bird for further symptoms such as lethargy, loss of balance/can't walk, ruffled/unkempt appearance, and considering whether or not they may have experienced conditions that might have caused an overload would be a few other things to consider when determining if Coccidiosis is a possibility (still in original coop, but bedding/feces became wet which then becomes a breeding ground), but of course -testing is the only way to know for sure if there is a Coccidiosis overload.
. The forum will always be here for you though to pick our brains or just talk chicken. Don't beat yourself up though, it's not your fault and you did the best you could and obviously loved her and I'm sure she knew that and took comfort in your care.
