I was reading a current WOW "remember when" blog the other day and it mentioned that back in Vanilla, a hunter stacked +heal gear and was able to have his pet solo a world boss! Blizzard then nerfed spell damage and +heal to not effect mend pet.
On Anathema, +heal gear was added with the AQ patch and I think still adds to your mend pet. It appears to add the full value of the +heal spread out equally among each heal tick.
Poking around the auction house, the mid to high fifties green "of healing" armor pieces add about 50-60 healing each. You could also dual wield two +healing weapons if you could find them and add +55 enchant to each and +heal on your bracer. I'd be curious to know what would be the most +heal you could stack.
As an example, if you could stack +900 healing, you could heal your pet for 1000 health for 50 mana with rank one mend pet. 1000 health = 200 health per second = +900 / 5 = 180 + 20 with rank 1 mend pet.
If you could use three pieces of the Giantstalkers set, you could add +10% to the heals, reduce the mana by 30% and increase the distance by 50% too!
Has anyone experimented with how much +heal you can stack and if you could tank and spank mobs with your pet that you normally couldn't?