There are videos on Youtube of people treating this illness, and does seem to look just like the ones on ducks with niacin deficiency.
In some of those videos they also did some therapies with putting them in pools of water for weightlessness for a very limited amount of time. However, they couldn't leave them in long it seemed, as one of the videos the guy said something about niacin deficiency also makes it so their down can't repel water as easily for some reason.
This is kind of interesting also to think about.
In the one video I saw, the guy had 3 ducklings with it, and one recovered but two got worse.
I'm not sure if that's the standard norms though. Who knows what the probability ratios would be really with a bigger sample. But if even one can recover that's a chance for some hope.
But one thing also that I'm not sure about is, let's say you do get this one to recover, does that mean its offspring would have a higher chance of getting this illness also, passed down through genes or something? (But it still could be good as a meat or egg producer for consumption maybe?)
Hope I don't sound callous; I'm just trying to address some of the practical thoughts. And I hope I didn't say the same thing as others, because there were so many pages in this particular threat to read them all.