Been there. One month ago. Sorry for your loss.This makes me sad too. It is the 2nd fish in a row for me.
I've always fallen squarely in the "don't treat prohylactically" camp because ALL drugs have negative effects as well as positive and I have always believed it unfair to subject our fish friends to harmful effects unless absolutely necessary. But this past few weeks has me rethinking a lot of things :'(