Behind the spectacle of a high-stepping "Big Lick" Tennessee walking horse competition, a criminal contingent is at work. Unethical horse trainers use a technique called "soring" to inflict immense pain on horses' legs and feet, forcing them to perform the desired artificial, exaggerated gait. Showing a horse that has been abused in such a way is illegal under the federal Horse Protection Act, but the industry itself is responsible for policing the horse shows. That conflict of interest enables soring to continue.
Pulling back the curtain on soring reveals one of the most gruesome and cruel horse training methods in existence. To sore a horse in preparation for a competition, trainers apply caustic chemicals, including mustard oil, diesel fuel, and kerosene, to the skin above the horse's hoof. They cover it in plastic wrap to cook in the substances, leaving the skin underneath raw and sensitive. The horses are then ridden with chains around their legs that chafe with every step. They are also fitted with tall, heavy stacks of pads that force them to stand at an unnatural angle, and add height and weight to further exaggerate their gait. Foreign objects are often inserted between the soft bottom of the hoof and these stacks, adding to the horse's suffering.