Well, the first thing I noticed is that the tongue seems to be cropped off just a little bit too close! Of course, if that’s the way the picture was taken, it can’t be helped, but if not, I think it would enhance it to leave a little more “tongue room”.
It looks like you got the focus on the eyes, which is where you normally want to focus on an animal. But I think it is focused a little bit too far forward, the corner of the eye and the tongue aren’t really in focus. Again, that is almost impossible to know when you’re taking the picture, but if you consciously try to focus on the eye, you’ll be more likely to get better results.
I attached a closer crop so you can see what I’m talking about. As you can see, the part of the dog that is the closest is in focus, but the eye is only partly in focus. Maybe raising your aperture to f/8 or so would have helped some.
