Wolves no longer sprint to aggro mobs

Duplicate: Simply observe any wolf aggressive to any mob or player, whether wild or player-owned. No increase in speed is observed as was in older versions.

Note: I am not familiar with intended changes to wolves, and was unable to find any mention of a removal of wolf-sprinting in official changelogs. I am assuming that this is not intended behavior as once wolves could outrun spiders, and now they can no longer outrun skeletons. If I am wrong in this assumption, it would be appreciated if someone would let me know.