I think it could use some kind of simple background. To me, It has a more domestic feel than a wild feel with the current clean background. I wouldn’t try for much detail on the background through, just more of a suggestion of the habitat and you don’t want to take away from the wonderfully done dog.
Well done. I struggle with backgrounds. I would go on Pinterest or just google perhaps wolf or wild dog portraits and see options/ideas and as Brad said, perhaps something representing wilderness will pop up. (I tried it and saw a few nice ideas)