Kind of off topic but am i over reacting?

I went to walmart today to buy some cat food..(fancy feast appetizers which my cats love)..My aunt proceeded to put about 20 of them in the cart..when i looked at them in the cat there were "black" things on them..when i went to the shelf to look there were TONS of black things all over the shelves,,cat food tins and boxes..mouse droppings. I went nuts in the store...(my aunt said all the stores have mice and rats..the cans are sealed..I told her YOU eat them then because i wasn't buying them.)..i then proceeded to find the store manager and give him a tin ear..i know all stores have these problems but that was uncalled for. Can people make their animals sick by buying food if the mouse dropping are on them even if they are sealed???? I really want to call the corporate office and complain now also.