Red lines illustrate the multiple unhealthy angles this foot has developed. I replaced the horse's too-small shoes (upper inset) with rolled-toe heart-bar shoes (lower inset) so his feet can begin to grow at a normal angle (yellow line) that matches the slope of his pastern. | ? Practical Horseman

Underrun Heels in Horses

On a healthy foot, heel and toe grow from the coronary band to the ground at the same angle; when the angle of the heel is less than that of the toe (making it look flattened out), the heels are considered "underrun."