Prazi wont work for camalnaus, every time I have tried to buy it in liquid form (adtape) it has been very expensive at vets over $100 a L from memory but it has been a long time since I tried..
I have some arrest C at home and haven't had much luck with any fish living after being treated with it, what dosage rate do you use Burn?
I believe the picture of the fish that you have put up isn't look too good already, I can't even identify what type it is it almost looks like it has been drawn on paint.. But the fish can survive ater being badly affected, usually when it gets as bad as pictured it is usual to expect some sort of long lasting damage to the internal organs of the fish as it is usually totally filled with worms by then.