WHY DON'T CATS FART?

I'm constantly being asked by my fiancé, "Did you fart?"  First off, when I fart, everyone knows it was me.  You NEVER have to ask.  Secondly, I'm tired of being asked when it was clearly the dog.  How do I know it was the dog?  Because the smell is what we have come to call, "the garbage fart."  It doesn't actually smell like garbage so I'm not really sure why we call it that.  The strange thing is, the cat could be sitting right there and never once has anyone thought the cat farted.  So do cats not fart?