A shod horse has LESS PROPRIOCEPTION, or tactile sense, so is unable to make wise choices as to where to place his hooves - this also increases the possibility of injuries.
NAIL HOLES cause dryness to hoof horn, weakening the walls and equip fungus and bacteria with an entrance.
The actual NAILS act as a conduit for environmental temperatures to penetrate deep into the hoof. This can be clearly seen on thermographic images
The lateral cartilages of the hoof enable the two sides to move up and down independently. DECREASED LATERAL FLEXIBILITY increases the risk of inflammation, wear to the joints and therefore injury. Removing this lateral movement, which protects the hinge joints on uneven or irregular footing, leaves these cartilages unable to perform their job.
Raised from the ground this DECREASES SHOCK ABSORPTION properties of the hoof. The cartilages and digital cushion are in the back half of the hoof, and unable to function without contact to the ground.
Research at the University of Zurich showed that metal shoes generate a VIBRATION FREQUENCY of 800 HZ. A frequency that is harmful to live tissue and can cause arthritis.
Growing at approximately 1 cm per month, a healthy hoof also wears away what it does not need. MAINTENANCE INTERVALS of the shod horse are often not regular enough and, unable to wear their hooves naturally, a change in posture between shoeing is common. Over time the hooves slowly deform, leading to various problems, like contraction and migrated heels. The natural symmetry of the front hooves changes to an elongated narrower foot.