It can be pretty fast even in bronze gear. You should be able to parry with upgraded bronze buckler and 3-combo attack with bronze axe. Repeat 5-6 times and it is done. However it depends on your skill. Lower skill levels will drain your stamina faster so it will take longer to kill it.
If you bring it over surtling spawner you can do it even faster. While staggered over surtling spawner, abomination will take more fire dmg.
Also i have read that elder power helps a lot.