Personally i hvnt tried 0cd dogs build .. i've only tried reduced cd zdog (giyua + homunculus + grasp + tribal rites passive) .. few things i noticed:
1) using reduced cd zdog gear will result it lower dps (homunculus vs ukh, giyua vs vision/mempo, grasp vs rare/hf rings)
2) sacrifice dmg will be also much lower as a result
3) in PvE (non ubers) time taken for zdog to "hug" intended target cant be outright controlled (as opposed to aiming using other spell) ... the fastest way i found to get zdog close to intended target is to cast a bit far from mobs (avoiding zdog to engage non intended targets) then SW as close as u can to intended target so ur zdog will "teleported" next to it (u need to be at quite a distant for the zdogs to be tele)
4) pros: huge health replenish/healing (24k) .. free health globes for party members

The way i see it 0cd build is useful/easier to use n target in ubers (benefit party as a whole i,e health globes) .. MAYBE will be imba in PvP

Gears for 0cd:
- Homunculus: max 20 sec cd
- Visage of Giyua: max 9 sec cd
- Mara's Kaleidoscope: max 8 sec cd
- Skull Grasp: max 7 sec cd
- Stone of Jordan: max 8 sec cd
Tribal Rites passive will give 11.25 sec cd

Base cd for summon zdog is 45 sec however bear in mind that it takes 2 casts & animation frames for those are roughly: sacrifice+explosion (4th dog exploded) = 1,12 seconds (figures taken from a wd player findings in another forum). Also u hv to take into account the travel time taken for the zdog to engage/hug intended target.
If u take into account 1 sec casting and Jaunt (3 sec) ... getting 4/5cd is sufficient to constantly use zdog/sac. Basically after using tribal rites, u need another 30 sec cd from other gears.
The highest dps obtainable is if u dont use Homunculus but 20 sec cd is pretty huge. Giyua is pretty decent to use since it gives AR + high intel + mana regen, So is Mara since it has fixed main stat + AR + 3 random rolls (can get trifecta if u r rich lolz) .. SoJ also wont compromise your real dps too much.
Easiest combo is Homunculus + Giyua but it will compromise your total dps. Imho best combo would be Giyua + Mara + SoJ + Grasp

Skill setup:
Must hv active skill would be summon zdog/final gift & sacrifice/for the master. For passive skill, Tribal Rites & Zombie Handler.
Other useful skills, perhaps Grasp of the Dead/Unbreakable Grasp (to keep target in place) .. Wall of Zombies/Unrelenting Grip could also be useful to slow down enemy & stop enemy from getting close to u while making it easier for zdog to hug target.

Anyways .. current price of reduce zdog cd is ridiculously high which makes it a huge investment to even consider (for me at least). For those who want to give it a try can spend a reasonable budget by getting Homunculus & Giyua (2 of the cheapest reduce zdog cd gears) b4 depleting your bank balance on mara/soj.