We all do agree, going barefoot in sport is a solution for some horses, not all. But indeed horse shoes do have some disadvantages.
Shoes do not solve problems but mask them. Horses might not feel their discomfort anymore but the cause of this discomfort has not been resolved. Making an animal feel better seems a positive and humane thing to do, but for not many other health issues we would put animals on permanent pain remedy without looking for a proper diagnosis or treatment of the cause.
When hooves are weak or sick or the horse is unable to walk comfortably over certain types of footing, other types of hoof protection can be used during the time it takes for the hooves to adjust or recover. Although hoof boots and glue-ons also have disadvantages they are generally less damaging than nailed on metal shoes.
1) Decreased shock absorption
The digital cushion and hoof cartilages are the flexible parts in the back half of the foot that provide natural shock absorption to the leg. On Youtube you can find several slow motion videos that compare the shock absorbing qualities of shod and unshod hooves.
2) Fixation of the hoof
Shoes decrease the natural flexibility of the hoof which is needed for optimal hoof mechanism. Hooves and lower legs of shod horses are normally colder and more prone to injury because of lack of circulation. Also horn quality and growth speed can be affected by the lack of nutrients and oxygen in the tissues.
3) Less grip and tactile sense
Shod horses have less grip because metal is slippery compared to hoof horn. If you have the chance to compare the sure footedness of shod horses and unshod horse on different terrain you will find out barefoot horses have much more grip on snow, ice, tarmac and even wet grass. Barefoot horses have better tactile sense and proprioception so they are able to choose more carefully where to place their feet, which also prevents injuries site importante.
4) Hoof maintenance intervals
Healthy hooves grow approximately a centimetre per month. Shod horses do not wear their hooves naturally at all and are often not maintained regularly enough. In between each shoeing the horse will experience quite a change in stance and the hooves tend to slowly but surely deform over time, leading to problems like contraction and underrun heels. Front feet that are naturally round will become more elongated over time. One of the many benefits of barefoot horses is that they can be maintained whenever necessary without needing to remove and reattach shoes or worrying about the nail holes being too close together.
5) Vibration frequency
A research of the Zurich University shows that metal shoes generate a vibration frequency of 800 HZ, a frequency that is harmful to live tissue and can cause arthritis.