Your depiction of the fur is really admirable and unique. You give the dog an aura without being obvious about it. A special glow. You use very nice colors. I like the way you use very subtle blues and purples around the outline and shot through the fur. And then you use a dry brush to paint the outer tips of fur.
The way you dont make the ears perfect mirror images of each other gives this little dog an expression as if its reacting to you talking to it. This particular ability is rare. Im sure you captured that dog, not just a generic Chihuahua. You even included his eyelashes, another small feature that makes each animal unique. His eyes are brilliant, sharp and looking right at the viewer. You managed to make them look moist like they are in small dogs whose eyes bulge a bit.
I know what you mean about being a bit confused and suspicious about the time you put into it. I have a tree Ive been painting since last year and Im still not finished! The first painting I did of that same tree took me a whole two hours!
Its finished so you can put it down.