I think you have improved very much. I like that you are getting to the dog's eye level (as someone suggested in the old post).
The last one with the dog in the water I think is the strongest here. It's technically good and has decent composition. That and the wet dog has a great look.
Also notice how much better the image is when you take the leash off and don't have that distraction in the photo.
How I would improve the other three:
The biggest problem with the first (with the ball) is the background is distracting (mostly the tables and the sky is also close in value to both the ball and the man.). I think if you shifted your camera angle you might have been able to separate from the background a bit more. Other than that, I think this shot is just fine and the color and exposure look good (not bad getting detail in the dog and the man's skin).
The one with the shoe looks a little cold on the color balance yet especially if you compare it the nice warm white balance you have on all the others. I'd white balance so the shadow is warmer since only 1/4 of the dog is getting the direct sun. Also, the dog's head seems to be abnormally large. Might not be the right lens for the shot. Finally, I'm not letting you off for the shoe. It's digital and the 7D has a pretty good buffer. Shoot some more shots and get one without the shoe.
It's not a 12 exposure roll of film where you have to hold back.
The portrait of sorts looks right on with exposure and color. Focus is good. Everything is technically good. It might be better if the dog filled the frame a bit more (the head most often should not be dead center like this), Oddly, I like the edge of the owner's body in the photo although the leash is distracting.
You might want to think about getting closer to the dog's face and filling the frame with it. Unless you have added to your lens collection even the 50mm with the 1.6 crop is going to seem a bit distorted close especially with dogs. You might want to think about a bit longer lens that can focus close.
This is all very nit-picky and if you warm up the white balance on the shoe, I think most people would be glad to have images like this of their dog. You've improved your dog photography a lot.
Pets can be a very difficult subject and dogs can be right up there with some of the hardest of pets (it depends on the situation and the dog). They are small. It can be hard to get them to be still long enough to compose (let alone get focus on the eye). Sometimes they get nervous and just won't look right even if you get the perfect shot. Cats can be far worse - they will simply be stubborn and refuse to be photographed.