I love the pose, reminds me of what my dogs used to do, hehe... Superb anatomy, great pose, I adore the cell-shading (I think that's what it's called O-o), and I love how his left ear is, like, smashed against the floor.
He's adorable. Very well done. I love his expression! =3 The only thing that seems a bit off to me is his right front paw. It looks just a bit big compared to the rest of him. Otherwise this is beautifully done!