It seems this disease can strike any cichlid, but discus seem to get hit the hardest, as the secondary infections can be as bad as the disease itself. Angels get hit pretty hard as well.
One thing the Dr. never hit on was whether or not water changes were needed during treatment. I would expect they would? To me and my tap water being 8.0 pH, thats a crazy amount of chemical being placed in the water. Thanks to Hillbilly for the notice on low pH leading to bacterial filtration destruction. That could be double trouble.