As one would expect(devoute animal lover here
), I love this piece.
I envy your ability with Oil, I will try it eventually.
The colors are beautiful, and the Horse is VERY nice!
I am NO expert, but as to your question about lights and shadows, I'm confused as to where the light is coming in(direction).
To me it appears most light is in behind subject Horse, yet I see you have added additional light source to facing side of horse? Does that make sense? In other words I guess I would expect if light is coming in behind Horse, then this side of horse should be darker in shading?
Well, enough of my very novice opinion, but let me just say again I like this piece very much. Am anticipating others more experienced opinions to help with my learning as well.