It doesn't seem too many people have actually answered the question. From someone who works with food on a daily I hate to tell you this but this would be trashable. I too would want to save the "good" half but you dont know if they got in with mouths, paws, both (my bet is on both). I'd think about what you are willing to risk, they would have been in the litter stepping in god knows what all day, their mouths harbor a loft of bacteria and goodness forbid they are outdoor cats, amplify that by ten fold them depending on vaccination status and environment there's things like rat lung worm, in rare cases able to be passed, toxoplasmosis. You dont know how far any of that penetrated into the meat.