I think this may be some sort of pathfinding error. Wolves converge on and attack a location without any mobs in it, while the mob they are trying to attack is located a few blocks away. I have only encountered this bug/glitch once, but because there is nothing for them to attack their target does not die, making it impossible for the attack cycle to end. If this is a random glitch rather than a code bug, I'm open too suggestions on how to fix it.