Interesting. I know what you were going for with the silhouette, but I think the dog blends a little too well with the silhouette of the rocks behind. The sun does provide a nice hairlight to cue us on what the subject is. I like that.
Next time, try getting even lower than you were when taking that photo to get more of that "hero dog" look and use up more negative space. Also, level your photos. You'll be surprised how much difference a flat horizon makes.
Oh, for some reason I forgot to mention it in my previous post... Next time try using some fill flash with the dog. It will help separate doggy better from the background. Use your flash exposure compensation to control the fill and adjust to your taste.
IMO, it doesn't need a lot of fill, I quite like the silhouette, it just needs more separation.