Composition wise it's not bad....a little more space to the right would be better, but vertically it's perfectly balanced. I really like the dark shadow of the tree behind the dog, contrasting greatly with his white head. Very nice. The perked-up ears are a dead give away about not being alone, though.
I can't beleive this dog is alone. It's the perkiness I see, and looking intently to our right. Also, subject is centered :-( . You left plenty of field to show the alone concept.
