Horses started wearing horseshoes when royalty built their castles up on big hills for safety during medieval times. The horses no longer stayed out in the fields but were brought into stalls where they stood motionless until needed. Stall sanitation was not a priority so the horses's hooves just stayed in urine and scat for days or weeks at a time. As a result, their hooves got soft and would rot away from the ammonia in the urine. Someone came up with the idea of putting metal on the horses hooves in an attempt to make the hooves stronger. The commoners below noticed the metal on the hooves and figured that since the king did this, there must be something to it. The metal shoes were also a huge asset in battle - since war horses were trained to strike out with their hoooves to inflict damage on the enemy. . This would have been around 5 AD or so. And, it simply caught on.
The American Indians never shod their horses - occasionally an Indian horse would be seen with shoes on but the horse was stolen from the white man. The Mongolian nomads never, and still don't, shoe their horses. And, many other groups don't shoe the horses either.
John Lyons hasn't shod his horses in over 10 years. My 13 darlings are never shod - for years and years and years - but they are lucky enough to have near natural conditions to reside in. They are ridden approx. 5 hours a day in pretty rugged terrain and lameness, so far, has never been an issue.
Generally folks shoe because that, in their mind, is what has always been done, so they do it.
It is said, by "those in the know" that shoes inhibit circulation and are a strong cause of lameness in present day horses. But, of course, most of our horses now live in artificial conditions versus out in the fields as they once did which also is a detriment to healthy hooves.
It's a pretty interesting controversy - to shoe or not to shoe. So, who's to say? Only you can make that decision for your own darlings.
I am not a proponent for or against - .
Mary Dixon Adventure Horse Riding in NYS RideNYS.com
This info was compiled from various sources - balancedstep.com, naked hoooves, Cindy Lyons, The Soul of the Horse, among others.