Topline is the term used to describe the muscle coverage over the top of the horse’s neck, withers, back, loin, and croup. Because topline is muscle, a horse with a good topline will be stronger and more athletic, and will present a more pleasing appearance. What should we feed to develop the perfect topline? First we must understand that the shape of the back can vary greatly from one individual to another, and so the topline will vary in length and in curvature, with some relationship between the two. Horses with toplines that are sunken in over their withers, concave along the back and loin, or dished in around their hip bones and hindquarters will have diminished strength in those areas.