LVSteve said "The household there feeds some local cats, but all of a sudden they started turning their noses up at one particular fish dish."
I keep 6 different flavors of hard and wet cat food for him, and rotate them randomly twice a day, but I still get the dismissive turned-up-nose-walk-away-in-a-huff about once/week, sometimes for days on end. After many years of changing food brands and flavors, I've learned to just leave it and after a day or two, he will eat it. The surprising thing is that after this rejection of my offering, he returns to eating any flavor among the six with gusto.
In the end, he's a cat doing what they do; when they want, maybe, I'll think about it; are you kidding me! - maybe tomorrow, well... we'll see, if my staff pleases me.