Dock shows on only one screen on OS X Mavericks
If you're using a stacked display configuration, as in main monitor with the secondary above, then the dock does not appear on the second display. If it can or does, I'd like to know because this is how I run my setup. 

If you have them oriented right to left, then the dock will appear. In my limited experience, only one image of the dock appears at a time on whichever monitor you activate it on. You have to play with it, as the cursor motion seems to need to be elongated or dramatic or whatever. Not a big thing, just different.

It's there by default, trust me. HTH.