Well the title pretty much sums up the action here, with the unfortunate deceased being converted by a pair of reprobates into product for the Lotus Cat Food Company. The tainted food then drives the cats that eat it batshit crazy with a bloodlust for human flesh. It's a your textbook vicious circle, man. "Grinders" - directed by one man schlock movie factory Ted V. Mikels - was part of a famous schock triple bill with "The Embalmer" (1965) and "The Undertaker and His Pals" (1966) that played the country's grindhouse and drive-in theaters back in the early 1970's. You gotta fucking love the voiceover narrator in the trailer: "Do you know what this is? IT'S A CORPSE GRINDING MACHINE!"