It's a great start, but adding an ear definitely would make it look more horse-like. Maybe adding in a mane-like design to the neck would also help make it more horse-like. I understand by looking at the image that you're trying to keep it sleek and streamlined so that it fits in with modern times, so if you can somehow come up with a flowing design on those terms, you'll have something! I might also suggest you smooth out or completely edit out the small "fang" on the horse's muzzle.
These are just my opinions/critique and if you wish to disregard my commentary, by all means do so! I mean nothing negative by them, and wish you luck on this project and its final draft.
As an artist myself, I know it's sometimes hard to hear what's wrong with your picture, but it can also be really awesome to hear input from others as well.