The build: http://eu.battle.net/d3/en/calculator/witch-doctor#fURdQP!ZbU!caaZYZ
Reasoning: First zombie bears might not seem optimal for boss fights, but ive found them to out perform all other abilities. When fighting bosses they tend to be rather large so when 3 zombie bears are summoned majority of the time at least 2 of them hit.
Firebat is good especially its range and has good dmg, and a good alternative if you're not familiar with zombie bears, but their dmg if the boss is large enough that 2-3 bears can hit is not comparable. Splinters are a joke.
Spirit walk with jaunt is the best decision for spirit walk for almost any spec it pretty much grants immunity for up to 5 seconds allowing you to escape and or lay down your soul harvest.
Soul harvest (siphon) is decent for this build but can be replace ive yet to find anything better so ive kept it for quick health regain and some bonus dmg.
Hex (hedge magic) is awesome, while the cc doesnt work on boss its a great little heal that has saved me countless times.
Big bad vodoo (ghost trance) i found is great lay this bad boy down and you can pretty much tank almost any boss for 20 sec.
Fetish army (devoted following) you might ask why devoted following, what ive noticed is fetish army dmg is ok at best, but it can sometimes grab a bosses attention and make it focus on the tiny little bastards with a cd cut down in half it can greatly help survivability.
Jungle fortitude (do i really need to explain? 20% dmg reduction yes plz)
Spiritual attunement ok here im up for changes im not sure if zombie bears apply "poison" acutally reducing dmg done by 20% so if they do id go with that but ive yet to test it and if someone could let me know id be very greatful, another option is spirit vessel, now im not a huge fan of this one but it has potential seems to me it bugs out a ton and 90sec wait is quiet a while.
Vision Quest keep all your abilities on cooldown and you win. Spam zombie bears till your hearts desire.
This build requires quiet a bit of being in close range with bosses so what you need to consider is finding the best moments of nuking the boss. Like pop big bad vodoo and fetish army and light that !@# up for 20 seconds but after that youll need to start being careful and very cautious.
Im currently at around 6-7k dmg without soul harvest
and around 26k health id be more acurrate but servers are down :(.