Horses noses can very easily become distorted in your photographs if you get too close, or zoom in too much. These aren't then suitable for a portrait as it accentuates this area.
To remedy this, we just need to be at the horses eye level, fill the frame with the horses head, but try not to be zoomed fully with the camera to do this. Take a couple of steps forward and zoom a little if needed.
Don't forget if you don't want the bridal in the portrait take it off during your photography session.