First of al the perspective is really off. The dog is supposed to be in the slight birds eye view am i right? But the background doesnt looks like that at all, english isnt my mother tongue its really hard for me to find the right words. Since the background is drawn wrong the dog seems to levitate. The fence is showing in the wrong perspective, its like the normal 2d perspective.
I suggest you to search for some references in the near future, take a pic in the birds eye view and experiment with it by drawing creatures/huma/dogs on this image and see how it works