I feed my cats this: http://www.nlpp.com/products.html?topic=vegetarian
All three of my babies are very happy and healthy cats with bright eyes and shiny coats.
Natural Life does not conduct animal testing, and they do not outsource any portion of their production. The food is pretty expensive, but I don't have to worry about rat poison, e Coli, etc.
And thanks to this food you will never need to know how to treat worms in cats.