Thank you for your advice and the great article. With a blood test, you've mentioned it could be done just by clipping a nail? I have been looking frequently at Napoleon's feet. It could be a huge mistake on my part, but I haven't actually tried to grab him to look more closely. I didn't want to stress him, especially since I know he's going to be stressed when he goes to the vet again in these coming days. But from watching him in the cage, I can't see any sores on his feet that would indicate bumblefoot. I hope that it isn't it. I've always heard to have a variety of different natural perches to avoid bumblefoot, and so that's what I've done. I also haven't seen the white spots that would indicate gout. I've read online that in some cases some birds have a lot of small white spots, and in other cases larger white spots like lumps. I can't see any. But something is clearly wrong his feet.
I'm not sure how much experience the vet who saw Napoleon last Monday has. I spent a long time that morning calling every vet in our area and asking for an avian vet. Everywhere either had an avian vet but no appointments, or didn't see birds at all. This is a problem I've had several times in the past. I'm fortunate to live somewhere with several avian vets, even if at far distance from my home, but it's always near impossible to get an appointment.
The website for the clinic I went to last Monday doesn't mention much information about their vets. The facebook page for the clinic does mention that the vet treats exotic pets like birds and reptiles. I was a little worried by the fact that she didn't recognize Roudybush at all when we talked about whether the Lafeber vitamins should be added to Roudybush. When I went to the clinic, she took Napoleon to another room, which was darker and Napoleon would be less stressed, to examine his heart and lungs. At least at the time, she seemed knowledgeable. If I remember correctly, she had said that with budgies being so delicate, any small factor could cause illness, even the change in weather. I took out my cellphone to ask for which vitamins she recommended and she pointed at the Lafeber vitamins in the Google search, because she thought Lafeber was more trustworthy since Lafeber worked with vets to make their products.
It can be difficult to get an appointment at our usual vet clinic. I know for a fact one of the vets there is has significant avian experience, but I've never been able to get an appointment with him. Usually when I can get an appointment it's with another younger vet who according to their website treats birds and reptiles. It's not mentioned on the website, but he's mentioned owning a conure in the past. I had a budgie back in 2017-2018 whose beak kept growing unusually long. This vet examined that budgie several times, though as far as I remember never did any tests beyond a physical examination. He always concluded that the budgie seemed fine and said that he couldn't feel any growths during the physical exam. He seemed knowledgeable when we spoke to him. That budgie sadly passed away suddenly when she was about 8 months old.