This is a very good spontaneous shot! The dog looks like he is looking right at you! However, I think that the nose should be more in focus. You can achieve this by having less zoom, but digitally zooming more, especially if the image is high quality. There is very little blur, and the rest of the dog is in very good focus, with the background unfocused just enough. There is amazing detail in its fur and its ears. Pets are a pretty cliche shot, but the way you have taken it captures an angle that is not too overused. Overall a very good shot!
Great pic. I like how you focused on the eyes and the ears because they are the primary content of the shot. Perfect depth of field. The slight blur on the nose makes it look silky and soft. I don't know how to manage depth of field with such a long lens. You are very skilled.