Yak Corpse is never moved

In DF, I have a refuse pile set up fine, and I have pressed o-r-o to allow dwarves to gather refuse from outside, but there is one yak that decided to die in my dining room, creating miasma. No matter what I do, I cannot remove it.

Now, it is a skeleton, but I still can't figure out how to remove it. Maybe because it's very heavy, the dwarves cannot lift it?

Let me be clear, I've marked it for dumping, and forbidden it. Other types of refuse are being moved to the refuse pile as well.