Just keep the pet exp distribution in mind
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Pets and Experience
Oct 23rd update: "Classic pet experience distribution."
Oct 23 2011 Patch.
In order to receive full experience for a kill solo, you need to do more than 50% of the damage to the mob. If your pet out-damages you or the group, it will take 50% of the experience away from the kill. This is a major change from the previous system, in which you only needed to do a single point of damage to the mob in order to get full experience. If you are grouped, your group and you will get full xp from the kill.