Interesting. Didn't know that. Begs the question though why nobody kills them quickly.
Because it's a level 25 FP and most people have no clue how to play properly at that point, especially when the dogs should be kept away from the boss who the tank should be beating on (the boss has an aura that increases the dog's damage so they need to be separated). People tend to be idiots, especially when it's lol-leveling content. If a strategy isn't readily and *obviously* apparent, most people couldn't be bothered to figure it out or even to follow it if it's spelled out to them.