There are lots of different styles of corrective shoes because of the many things that can go wrong with a horses foot, plus there are shoes to provide more traction, and different ways to keep shoes on the horses foot besides just nails, such as shoes fitted with toe and side clips that take the strain off the nails and help keep the shoe on the foot. A single shoe can have one correction, or it also could have a combination of corrections such as side weight, swelled heels, rocker toes, bar shoes or trailers. A horse's feet are different shapes front and back, and mule shoes are completely different shapes, while ox shoes are two halves, because cattle have cloven hoofs. There is a lot more to shoeing a horse than just nailing on a shoe. Shoes also come in sizes just like people. A foundered horse tends to have a long toe and be low in the heels, so many times and rocker toe and swelled heels helps the foot break over and the horse is able to travel easier. I you really want find out about corrective shoes and the things that can go wrong with equine foot, check out this site, and just scroll on down the page, there are tons of pictures worth thousands of words.
Farrier Services by Gary Werner