Do you mean Nutrish? That's what Watson has been on for a long time now (just recently switched to the Rachael Ray Just 6) and he loved it with no issues. It's not top quality, but it's better quality (and a lot cheaper) than big name brands.
And by that I mean it's not mostly corn. There is still corn in the Nutrish brand, but less than Pedigree/Iams/whatever else. But the Just 6 kind is corn-wheat-soy-free