Nice image, but I think you're having the same problem I'm having right now: lack of a macro lens. I guess you used a 50mm/f1.8 fix focal lens for your Canon, which works great for portraits but macro images will always be missing something. This lens is amazing for portraits (great bokeh and all) but you can see details that should be more visible on the horse and the chain. The detail reproduction ration is 1:6.6, whereas a 1:2 or 1:1 (true macro) would be best.
So my macro (et many portrait) are not as detailed as i want ...