Why isn't there a mouse flavored cat food?

Mice are not raised as food animals in the West and so proper facilities would have to be set up for the humain breeding, vetenary testing and slaughter of mice if they were to go into cat food. In reality it is much cheaper to use those animals already humainly slaughtered and vetted for the human market. Effectivly cat food can be made as a byproduct of the human meat market using those parts of the animal not fashionably eaten, this saves the producers money.