I ask that you read this critique from a "critique of the work" and not of the "artist".
That said, I think you have a good grasp of your subjects. You seem to be able to capture their facial expressions and their bodies very well. Even the curve of the tail and the tilt of the head is captured nicely. You seem to know how to show them at their best. Your subjects are not the problem, at all.
Composition seems to be the enemy, here. My adding just enough background to weight the dogs in the environment, you've cluttered up your piece. Notice the little pup in the middle left of your piece and the pup in the middle of the bottom and the middle pup on the right? The small addition of rocks is enough to "ground" your subjects. The bright wash of green grass is distracting. The large brown swirl at the center almost causes us to lose the subjects at the center.
Yellow is rarely a good grounding color. It tends to soften things to the point that the subjects seem lost. Notice how the white on the pup at the middle left seems so close in value that its legs and body are almost lost?
It would have made for a better piece if the background would have been a neutral color and your choice of pups had been all free-standing like the one at the center bottom. I know what you were trying to do but this would have helped unify the piece and bring them all together.