Well there is "the ultimate horse" set of morphs, which could get you closer. forgot where I got them from but they are by Daio, who is the expert on horses. I did do several, this was one of the better ones, as was the glacier one I did. Sorry about the hair. Soon altered as they are bryce textures, I hadn't got into poser in those days, only to put figures in my pics.

The greatest part of wisdom is learning to develop  the ineffable genius of extracting the "neither here nor there" out of any situation...."