The foreground legs are positioned nicely, but the background ones seem to go up somewhere into its torso instead of hip/shoulder. On a side view like this, the limbs should converge on almost the same spot. If it's sort of a twisting posture it has, it uh... Doesn't come across very clearly at all.
ALL tails are direct extensions of the spine, and should ideally follow the same "line" as the back, at least to begin with. This one seems to sprout from... Less savoury places.
Curve them lines a little more (especially the torso)! I KNOW it's tricky to do at that scale, but it is most certainly not impossible. In fact, these curves are exactly why i use circles instead of angular shapes, but more on that very soon.
The dog skull looks like
this (thank you wikipedia), but i've found it much easier to boil it down to
two circles/spheres. Of course, you'll have to vary the circles based on the dog breed, and in case of something like a pug, you probably only need one circle. :v
The rest of the skeleton apparently looks like
this (thanks again wikipedia but NOBODY DRAWS THE WHOLE SKELETON FOR GUIDING PURPOSES), so once again,
circles to the rescue! ... Ish. Circles are so nice for drawing living things because said living things are almost always round and organic, and many natural forms (such as skulls!) can be either derived or constructed directly from circles and ellipses (and their volumetric cousins). It won't be ENTIRELY realistic at first (or second, or third...), but that's fine, you'll get there, don't worry. The circles are just there to guide you, so if you should want to add things that break the outline then go right ahead. In fact, breaking up the basic shapes is often a good idea to do, and is my own numero uno trick to make my sprites look more complex than they actually are. :v
so basically tl;dr CIRCLES. Here's my take on a low-res dog silhouette which is about the same size as yours.
and oh yes circles
so they work on sprites too