I have purchases Performatrin brand before. Now, that being said, I do a home-made diet. Any time I have purchased that brand it has been for a dog/cat that just won't eat (for whatever reason). It seems to be the one go-to food I can get an animal to eat. And that tells me it's probably (but I don't KNOW this to be true) full of crap. Sort of like how kids will eat McDonald's when all else fails. Blech!
But check it out - I could be wrong.