I actually quite frankly love this. What paint program do you use?

While I'm not the best person as far as being critical and I love the entire piece a few things catch my eye.

The nose is very well done, the gentle light difference on the top of the nose gives it the right feel of texture, though the part of the nose closest to the viewer feels a little bit 'flat' as opposed to the upper portion.

The curve at the end of the muzzle 'lips' feels a little bit wide to me, though this may be intentional given canines do have more facial expressions then most people accredit, so this is correct depending on the viewers perspective of what the expression entails, (Happy, neutral, sad, etc...)

The fur is done quite lovely, especially the coloring which I'm curious how exactly you obtained that, but curiousity aside the flow of the fur, when going from the muzzle outwards it flows upwards towards the about the halfway point of the ear and begins to suddenly change directions, giving it what seems to be a bit of a off feeling to myself, the far right side of the face (The fur sticking out for example flows downwards as opposed to left-to-right a bit further to the left, instead of a gradual change.) Similar to the ear which to me in my admittedly intoxicated state seems to flow in two directions, almost a clockwards motion of fur on the white, inner portion of the ear. The 'center' of the ear itself, the solid black flows seems to flow in correspondence with the majority of the picture.

The last bit that seems just a tid bit off is the pupil itself, it seems to have more of a jellybean shape as opposed to the iris.

Please take my feedback with a grain of salt, I'm not the most experienced artist nor do I have an overtly critical eye but I hope I was able to help in some way.