What most people aren't aware of is that there is artificial coyote, fox and cat urine and also musk made and sold by wholesale companies. These companies aren't making it just to sell a couple gallons a year. And the artificial stuff doesn't go bad. My guess is their's a lot of real urine cut with these products to expand the volume of urine available. So as I said earlier I think theirs a bigger risk about whether your urine is "good" than whether it will go "bad". With that said I think there's still people that supply the real uncut stuff.