I don't think it would responsible to name breeders publically. You can all find the names on the lips of long time Dealers. Waddy and Grant Fugita can tell you guys the names I'm sure.
Papa, the better fish are not fed colored food. Only tateshita as tosai are heavily colored up. But yes, it is a 'disease' generated from beni ,although some say they have had it on other color cells. No one can deny however that is predominately a beni cell issue.
Bright researchers at the Nishikigoi research group have studied the problem for a while. And now that hikkui is not as common today as it once was, it doubt it is serious studied today like it was when it was envisioned a s a real threat in the 1980s. No virus has been isolated to date and certainly the 'old higher parasite worm' theory is abandoned. Maybe some of the new backyard dealers will tackle it as they did with KHV and use over the counter products to try and cure it?
Perhaps you can get the flea market board to take a run at it?
( I know, I know, I'm bad)
Seriously, I think the answer is as complex as the answer for cancer. And like cancer, it may turn out to be a synergy of genetic pre-disposition, enviromental factors, a virus? a skin cancer or a simple gentic skin condition?
But foods? I don't think so? Unless we are talking about a skin allergy and reaction to the food ingredients.
A few bright bulbs around the world are now talking about the contaminated wheat and gluten products being used in pet foods to include pellets now.That is probably a better and more interesting focus for food worries. I had a husky come down with kidney problems after eating some of that recalled dog food. BUT it was months before the high profile media coverage. I often wonder if koi wipe outs that are immediately focued on KHV might not be linked to tainted food? JR