This is extremely well handled, your drafting is excellent and treatment of details lovely. I find the inclusion of the paw a little jarring, the lack of detail makes it appear much closer to the viewer than the head, and it seems unnaturally twisted as though it were a right, rather than a left paw. I see that without the paw the animals neck would have seemed very long, it certainly gives stability to the composition. A bit more detail from some additional reference should fix this. I'm also concerned that some of the background is a bit sharp such as the apparent line between muzzle and right eye. Perhaps these could be lightened and blurred a little, leaving the leaf detail below the nose as the focus of the background? The line of the mouth is a bit severe too, perhaps some whiskers and hairs falling from the muzzle (using either eraser or white pencil) and some lighter details below the line? Finally, the lines of the ears seem a tad strong and could perhaps be 'lost' a bit into the background? I'd also like to see some white hairs/whiskers from the ears/eyebrows. This is a lot of babbling for quite minor criticisms of what is overall an excellent piece.