The one thing that I think hurts this photo, is that the dog in the background is right behind the first one. He should be either out of the frame or somewhere else where he doesn't blend in with the main subject. Yes, the 2nd one is out of focus and that does help...but I think it would be a lot better if he wasn't right behind.
I think the second is better regarding the dog in the backgound, but I would really like it without the dog in the background at all. I like the pose and lighting in the first one better anyway. Also, try to include the feet next time, you just cut them off by only a little bit.
One thing that you captured very well in the first picture and not so well in the second picture is the gleam in the dog's eyes. I was told recently (and it makes sense) that without a reflection or glow in the eyes of a person or an animal, the photo looks empty; dead. Had the background dog not been there for the first photo, I would find it outstanding. Regardless, it is still very good.