This is my 15yo (now 16) Basset hound at LBI last year. I should probably crop it a bit, but I like the emptiness around her. Just my personal preference.
Remember about the rule of thirds.
Generally (not always though) you dont want the subject to be centered, unless you're going for a symmetric kind of thing.
Im undecided if the centering actually works on this one or not. I would try cropping it to apply the rule of thirds, just to see if you like it. Wouldnt hurt to try.