I was worried one of my fish had parasites. Both sides of the body looked sort of shredded and inflamed. Then I realized it was a female and she was being repeatedly chased into a rocky corner and trapped between rocks - by overly enthusiastic males. We've had a bit of a break in the spawning chasing and she seems to be getting better. I'm grateful that it doesn't seem like a parasite or disease - but more like an injury. Regardless of what it was, I'd made my peace with letting nature take its course. Even dying fish are almost impossible to catch in a pond! I'm crossing my fingers that she makes a full recovery. Do you think your fish problem could possibly be caused by spawning?