We recently came across this YouTube tutorial posted by Internet Kidz Gaming. It explains how to quickly powerlevel your pets from 1-10. It also provides a method for bridging the gap between levels 18-25. Definitely worth a look!
NOTE: To our knowledge, these methods are not considered game exploits. However, they may not have been intended by the developers, in which case it's probable that a future patch will reduce their effectiveness.
The Fastest Way to Powerlevel Your Pets
October 03, 2012