Background is a bit splotchy/noisy - it's not a painting or anything is it? In any case, might be better if the DOF wasn't too narrow, but that's just my opinion. The point is, the dog is recognizable and the image fits the theme wonderfully. Love the dog's posture. Way to go!
A "cleaner" tennis ball would have worked much better for this image. It's a great idea. The dog's pose - with a slight tilt of the head is very expressive. Border doesn't help.
I think if the dog was a little more in focus it would have been a better shot.But that is only in my eyes. Your happness with this photograph it was realy counts.Good Luck
Good idea! I'd like a little more DOF, there's so little of the tennis ball in focus, and the dog is far enough away that you could get away with opening up a little more.