Hi, thanks for the link. I'm pretty sure I've read that one before but will be educational to re-read. Thanks again.
If your angelfish DOES have it (but it doesn't), you need to send it to a lab (my lab!) because it would be a huge deal.
That's my point. It would be HIGHLY unlikely that it's whirling disease, but you know how the rumor mill gets going. As the saying goes: "The wrong information in the wrong hands is a recipe for disaster. "
Just look at how much bad information has become common "standard" knowledge in the tropical fish hobby today. This is a perfect example of that quote.