If you're inclined you might take a stool sample to the vet and see if they can test it for pathogens...don't know how much that costs but it would be cheaper than a necropsy, I'm thinking.
Right after getting a stool sample I'd kill him and dispose of the body real well...what he has doesn't sound good.
I agree, it looks real bad. He's about dead as we speak, laying in the carrier, eyes shut and breathing heavy. I need to just suck it up and help him out of his misery.
He's super emaciated looking.. you can feel his entire skeleton through his feathers. I look at my birds daily and I sure had not noticed him being so scrawny, ofcourse his feathers are fluffy so it covers things up... I'm thinking he's really dehydrated. Maybe he ate something stupid. He's pooping several times an hour, nothing but yellow water. He's covered all over with pin feathers, like he's going through explosive molt. You don't suppose that could have affected him this severely? I know it makes them more prone to disease.... I just wonder if it could have caused him to become so scrawny, since feather growth does require a LOT of protein....