I agree something to like the above (maybe not the bigger curse icon) would work best, as it worked great in EQ1.
Just place the pet's health bar under the player's power bar and have it display thinner.
So instead of 4 pixels between the players power and effects, there will be 8.
2 pixels for the pet's health...
Adjust as seen fit. Here's a mock up:
I think this works best as it would look fine vertical or horizontal.