An occasional lost shoe is a fact of life. In most cases, a lost shoe is not the farrier's fault, so there is no reason to directly or indirectly blame the farrier. Some horses are more prone to losing shoes than others. The average in this study was 1.33 shoes lost per horse per year. One of the ironies of lost shoes is that the better a horse is shod, the greater the chances might be for him to lose a shoe.
Some people mistakenly judge the quality of a shoeing job by how long the shoes stay on.
In order to shoe a horse so the shoes stay on at all costs, a farrier would have to sacrifice expansion and support, two ingredients that are critical to a horse's long term soundness. Without expansion and support a horse is at greater risk of developing navicular syndrome, under-run heels and other conditions that lead to lameness. A shoe that is large enough to provide proper support and is fit properly for expansion will have more steel exposed at the quarters and heels and thus may be more likely to be stepped on and pulled off. In an effort to keep shoes on, some shoers use eight nails and long, thick clinches. The trouble with this approach is that if a shoe gets caught on something, long clinches do not open easily and can remove large pieces of hoof wall when the horse wrenches the shoe off.