Caustic chemicals: Mustard oil, camphor, kerosene or other chemicals are pasted above the hoof and wrapped in plastic to "cook". Horses often can't stand afterward. To pass inspection, trainers use anesthetic spray to numb sore feet, black polish or baby powder to hide scars, sulfur and acid to slough off skin, and sunscreen to attempt to counteract heat detectors.
Pressure shoeing: Nails, golf balls or other objects are hidden under the sole.http://www.fosh.info/links.html Friends of Sound Horses, has excellent resources to understand the awful implications of this
Padding refers to the "stacking" or the use of up to 5" platforms which throw the horse onto it's hind end. Stacks of pads alone can cause pain and tension throughout the horses' bodies and damage to their feet and legs. The hoof angles and the added height created by nailing stacks of pads to the shoes are dangerous and damaging in themselves, let alone without adding soring to this method.