There isn't a cooldown on Slice & Dice, but if it's the duration that you're looking for you could try Need To Know (
http://www.wowinterface.com/download...eedToKnow.html), or Slice Commander (
http://www.wowinterface.com/download...Commander.html)
Personally, I use Need to Know to track my Slice & Dice duration, Killing Spree cooldown & rupture duration.