I think that this picture has a great tone and shading to it. I really like how the fur is shaded. Anatomy wise I think the shoulder is a little too low on the right. The leg also just goes straight down maybe recheck the joints in the legs on a reference. And the muzzle needs adjustment to its angle though its pretty close. Overall i really like how neat the lineless is and the shading it really gives it a feel that the character is alive. I love the painting feel it has. The background looks great! And though usually i would advice more details i like it just how it is here.
Some advice would be to perhaps look at animal refs and practice different poses as well as anatomy.
hope this helps (first critic)