E.S.
My exhusband worked for CocaCola in the canning factory. The cans were scalded, dried, filled, lids sealed on, boxed, put on pallets and plastic wrapped all in just a couple of minutes without stopping. Once they are wrapped in plastic, they may sit for a day or two waiting to be put on a truck. If you find one that looks dirty wipe it off, but I tend to think that in general there woulnd't be anything worse that the stuff we encounter on a regular basis on it.
Looks okay, is okay. If it looks like it has dried yellow liquid on it and it's not Mt. Dew, wash it! (Although I see no reason a rat would want to be on it unless its not sealed) ;)