Welcome to the boards. We hope that you stick around and become and active participant.
On to the shot - bad news first:
I really really want to like this shot, but I just don't.
There are a couple of reasons - first, the rock competes with the dog in a fight over who should be the subject. The rock doesn't win this fight, but there should be no competition anywhere. Second, the bright areas are too bright - lots of places, but it is the worst on his left face. The term we use is "blown out". That is what happens when the white areas are so bright, they lose all texture. Third, I don't care for the green chin. Fortunately that is an easy fix in Photoshop. Fourth, the poor fella's eyes have just disappeared. You can barely see them. That makes it a less appealing dog shot for me.
Now, that being said, not all critique points out flaws. Critique also included making mention of what was done right. First, foremost, and most importantly, you managed to avoid the "looking down on the animal" perspective that far too many photographers (new and experienced) fall in to. You had the vision or perception to get down to the dog's level. When you do that, that brings the viewer into the animals world, rather than looking down on to it. Well done!
One way to fix the blown highlights is to (counter-intuitively) use the flash. A flash would brighten up the darker areas, which means that you can use a smaller aperture setting, which would keep the highlights from blowing.
Keep at it. This is very much a "nearly there" shot. You should be lucky that you have such an agreeable dog, so uou could re-shoot without much hassle.
The next thing worth mention is you choice for such a beautiful background. Next time, move a bit to the left - that would get the rock out of the way.
Very nice debut. Looking back now, I wish my first post was somewhere. My first shot was total crap.
Well, cya Monday.