History tell us that the nailed-on shoe first appeared in Europe at a time when nobility and their horses began to live in castles. Horses were kept in small, enclosed spaces, stalls and worked on brick walkways, roads and muddy conditions the horse would have avoided in nature. When the horses were stabled, their hooves were exposed to the harmful effects of ammonia created from their excrement. As little as .0003% per volume of ammonia gases are damaging causing destruction to protein. Horses also experienced a dramatic reduction in the amount of movement they were allowed. This lack of movement caused prolonged periods of reduced circulation to the hooves causing decreased hoof quality and growth. The resultant inferior hooves caused the horses discomfort so they were no longer able to perform, which led to the need for horseshoes. Horses have evolved the perfect protection over millions of years, nailed on metal does not improve this.
The horse’s natural environment includes herd life, open spaces and continuous movement 24 hours per day. Horses have become adapted and specialized to these conditions over millions of years of evolution. With dramatic changes in an ecosystem, there are likely to be consequences. In this case, the major consequence to an animal which was originally adapted for traveling long distances, and then significantly restricted in travel, are significant lameness and other related health issues of the musculoskeletal support structures.
While today’s domesticated horses still live in stalls over 70% of their life. One of the major factors influencing horse-keeping practices is the comfort and convenience of their owners. Many horse owners consider box stalls and horseshoes normal, even necessary. The devastating effects that these horse-keeping practices have on the horse’s health is not widely appreciated. The fact that the domesticated horse is often affected by health and lameness problems, and falls short of its natural lifespan, is proof that its basic needs for optimum health are often not met by their domesticated environment.
The effects of immobilization and lack of exercise are not just felt by the musculoskeletal system. A horse’s heart weighs .5% of its body weight. This heart weight over body mass ratio represents the smallest percentage by weight per body mass of any mammal on earth.
The healthy hoof compensates for the small heart of the horse. The hooves of the horse are auxiliary hearts pumping blood back up the leg to assist the relatively small heart. When the horse takes a step on the hoof, the hoof expands and fills with blood. When the horse finishes the stride the weight is taken off of the leg, the hoof constricts and blood is ejected out of the hoof capsule and returned up the leg. The healthy, pumping hooves take 50% of the workload off the cardiac system of the horse.