Hello! I will not be using stars for this critique, because I think they are pretty unnessecery. Please just ignore the stars.
The eyes seem a bit too close to the edge of the muzzle, next time try to move them a bit farther away. I think the tail looks kind of like a cat tail, because it is pretty long. The nose could be a little bit bigger. And finally the hind legs are short, and should be made a tiny bit longer.
The body structure is amazing! I love the paws and the eyes. The design is beautiful. The dog's size is great; not too skinny and not too plump.
If you would like to improve, I suggest studying the anatomy of dogs, specifically if you are going for a certain breed. Maybe watch some videos to see the way a dog's body looks when it is walking, jumping, running, all of that. That's all I have to say, I love the picture and I hope the critique helped!