Since I edited my previous post I wanted to point out that you will get information if your pet doesn't bring anything back. It's a bit of a weird thing because sometimes it happens where you see it in the list and other times you won't see it.

If you do not see anything (like experience for example) check under your pets information where it will usually say "X pet is out on a hoard" or "X pet is ready to hoard again" and this will give you information about what your pet brought back from it's previous hoard. This is what I found out recently when I saw it on my pets page. Hope this helps some people who might be confused!