I think the general composition is ok with very little to distract from the main subject and the tonal range of the picture is pleasing with nice fur detail and a catch-light though my personal view is that a little more contrast would give more impact
I am not sure about the choice to have the dogs eyes looking into the left side of the frame and would have preferred it on the right third as it gives more space to look into. A slightly lower POV to get both eyes level would have been nicer too IMO
Other that that I think its a very nicely take portrait. Keep shooting!