Is this Goose too Thin?

[Allears]

Say its a yest infection, what symptoms am I looking for? Could I try apple cider vinegar, or would this just feed bacteria - if it is actually a bacterial infection? I'm so worried for her.
I don't know how old she is. Maybe its old age and one of her organs has packed up, or maybe its a tumour. what should I look for?

I saw a post by @TwoCrows which spoke of massaging the birds crop and I tried that with Goose today for a couple of minutes. I gently massaged her from crop to the top of her throat and I felt something like an air bubble, about the size and shape of Smartie sweet. I rubbed it out, but no food or anything else came up. She seems a lot better for it and ate a whole slice of bread (wholewheat) and at least a quarter of a lettuce soon after that

. (I would have given her ice cream and bananas if she'd wanted at that point.) She drank quite a bit of water after that is looking a lot more spritely and even took a run with the goslings earlier this evening

I can't believe she's got any energy left, she feels all feathers and bone!

I'm still stumped at what the problem is / was and will finish the course of antibiotics and continue to monitor her progress. I hate that I have to leave her and go to work tomorrow, but it certainly seems like she's getting her appetite back

Thank you so much @TwoCrows , Kathy and Miss Lydia for your input and support.

Will keep you posted.

 

[Allears]

Completed the antibiotic course, but gooses poop is still watery. She is happy to eat bread, but very little else. She is still drinking quite a lot.
I've been told that one of her kidneys might have failed, which would account for the frequent drinking, lack of appetite and watery poop. She is less active than used to be, but I think that may also be because she hasn't been eating well and her energy levels may have been low. She's still preening, swimming and is a bit more vocal this week. Still hoping for a complete recovery