The U.S. Attorney's Office in Kansas City, Missouri has filed federal indictments against three companies allegedly involved in making and importing tainted pet food throughout the U.S.

The indictments were filed in KC because that was the port of entry for melamine-tainted wheat gluten.

From there, the product was sold to makers of various brands of cat and dog food, including Menu Foods, which has a plant in Emporia.

One of the indictments alleges a Chinese company used melamine to artificially reach the protein level required by pet food companies in order to save money. Melamine is toxic.

Another indictment charges a second Chinese-based business with mislabeling tons of tainted wheat gluten to avoid inspection in China.

And the last indictment says that Las Vegas-based ChemNutra picked up the melamine-tainted product in Kansas City and sold it to pet food makers.

Officials estimate at least 1,900 cats and 2,200 dogs died after eating the contaminated food.