Zombie Dogs (any)
Soul Harvest (Golden)
(o) Pierce the Veil
(o) Zombie Handler
Firebats, clocking in at an impressive 325% weapon damage for 40 yards.
Pierce the Veil: 20%
Total increased damage from spells: 200%
Firebats, final damage: 975% weapon damage per second.
with + 126 attack per enemy effected from Soul Harvest
And this is assuming increased spell damage isn't cumulative (stacking).
Add in any two spells that do not come at the expense of casting firebats, and you
have the highest damage output build for the witch doctor, based on current figures.
Credit to Damukag for first discovering this.