CHEMICAL SORING is the process of putting acidic products and irritating chemicals on horse's legs causing pain in order to force a horse to accentuate his gait in competitions.

Examples of agents used in chemical soring are mustard oil, diesel fuel, kerosene, salicylic acid, and other caustic substances on the pasterns, applied on the bulbs of the heel, or coronary bands, causing burning or blistering of the horse's legs.

These chemicals are harmful, quite toxic and sometimes carcinogenic, so much so that trainers must use a brush and wear gloves to apply them.

MECHANICAL SORING includes pressure shoeing, where the hoof is trimmed to the quick so that the sole is in direct contact with the pad or shoe. The horse may then be "road foundered," ridden up and down hard surfaces on the over-trimmed hooves, until they are very sore.

Trainers sometimes place objects, such as metal beads, nails, or screws, under the pad causing intense pressure, although this practice has begun to decrease with the use of fluoroscopy to detect such methods.

Abusive use of chains (such as using them with chemical soring agents) is also a common practice by sorers.

It is commonly found in the world of the Tennessee Walking Horse where horses are sored to perform the "big lick" for big prizes, such as the annual Walking Horse Celebration in Nashville, Tennessee.


SORING, by definition from the Horse Protection Act (HPA), passed by Congress in 1970, is:

“(A) an irritating or blistering agent has been applied, internally or externally, by a person to any limb of a horse,

“(B) any burn, cut, or laceration has been inflicted by a person on any limb of a horse, 

“(C) any tack, nail, screw, or chemical agent has been injected by a person into or used by a person on any limb of a horse, or 

“(D) any other substance or device has been used by a person on any limb of a horse or a person has engaged in a practice involving a horse, and, as a result of such application, infliction, injection, use, or practice, such horse suffers, or can reasonably be expected to suffer, physical pain or distress, inflammation, or lameness when walking, trotting, or otherwise moving, except that such term does not include such an application, infliction, injection, use, or practice in connection with the therapeutic treatment of a horse by or under the supervision of a person licensed to practice veterinary medicine in the State in which such treatment was given.”


  • The horse stands with his feet close together, shifting its weight to its hind legs.

  • Granulation tissue or scars are visible on the pasterns or coronet band.

  • Wavy hair growth or hair loss is visible in the pastern area.

  • The horse's pasterns have darker hair than the rest of the horse's coat.

  • The horse carries his hocks low and may twist them outward when moving.

  • The horse lies down for extended periods of time, and is resistant to standing up.

  • The horse resists handling of his hooves.

  • The horse has difficulty walking, and may fall.