It's very good! I couldn't do shading like that to save my life lol
There are two things that I think make it look a bit off:
1) while the rest of his head is angled away from us, we're looking at his nose dead on. Hold something like a credit card up underneath his eyes and look at the slope of the line. The top of the nose is straight. His nose and the hare-lip thing should be more to the right (ours, not his) of the muzzle (look at the lowest point of the chin and go up) and we should see *slightly* less of the right side of the nose and the right muzzle-cheek pad thing.
2) the line between his ears is too steep. Do the credit card slope thing again. Also, measure the distance between the right eye and the rounded top of the head, under the ear... then do the same for the other side.The right side of most of him is just a smidge higher, but the right ear is a fair bit higher.
That's just what I see, keep in mind I'm not a big artist. lol