Hitting a dead body in Dark Souls 2 severely drains weapon durability. It seems that the weapon takes damage for every frame that it is going through a dead enemy, thus the effect is amplified when running the game at 60fps. It's specially bad with large weapons that have a long range and slow animations.
Take a look at how much durability is lost on the first attack against purely live enemies, and then look at the durability lost when I attack the pile of corpses at the end. It's ridiculous.
This is the PC version, not sure if other versions have this issue.
![](https://i.ytimg.com/vi/UUvmMVOpr6M/maxresdefault.jpg)