Soring, or "big lick", is defined as the application of any chemical (e.g., mustard oil or diesel fuel), mechanical agent (e.g., overweight chains), or practice (e.g., trimming a hoof to expose the sensitive tissue) inflicted upon any limb of a horse, that can cause or be expected to cause the horse to suffer physical pain or distress when moving. This results in the horses picking up their front feet higher and faster than they would do in their natural gait. Trainers use soring to give a horse a highly animated gait in a short time period rather than spending time training them to perform this gait naturally. People who sore their horses believe that it gives them a competitive edge over other horses in the show ring. However, soring is illegal in the United States under the Horse Protection Act of 1970. Tennessee Walking Horses are not allowed to be shown without passing a USDA and HPA inspection for soring and physical inspection; they are not allowed to have scars on their pastern as it is associated with soring. Other breeds that have a history of soring including the Racking Horse and the Spotted Saddle Horse.
Soring is often mistaken for padded performance. The pads, sometimes called "stacks", that are seen on Tennessee walking horses in padded performance are made of rubber and are light weight. When a Tennessee walking horse is seen wearing rubber pads they will usually also have the addition of 6 oz chains placed around the pasterns to make the horse aware of the action of its front legs.
History
During the late 1940s and early 1950s, when Tennessee Walking Horses enjoyed a surge of widespread popularity with the general public, as the exaggerated front leg action, especially at the running walk, drew spectators to horse shows and helped increase the popularity of the breed. This action was also rewarded by judges. This began the rage for "big lick" movement. While "lite shod" horses with naturally good movement could comfortably perform this crowd-pleasing gait at the time, it took both natural ability and considerable time to properly train and condition the horse.
Some individuals, wishing to produce similar movement in less talented horses or in less time, borrowed practices used by other breeds to enhance movement. This included action devices such as weighted shoes, "stacks" (stacked pads), and the use of weighted chains around the pasterns, all of which were allowed within certain limits.
As these methods produced horses that won in the show ring, and as ever-higher and more dramatic action was rewarded by the judges, some trainers turned to less savory methods to produce high action in a hurry. These methods include excessively heavy weighted chains, use of tacks deliberately placed under the shoe into the "white line", or quick, of the hoof, trimming the sole of the hoof to the point that it bleeds or is bruised, increasing the weight of the stacked pads by driving in a large number of concealed nails and the controversial practice of "soring", which is the application of a caustic chemical agent to the pastern of the front legs to cause pain when the chains bang against the pastern with every step. The outcome of these practices is so much pain in the horse's front hooves that the horse snatches its feet off the ground as fast as possible in an attempt to alleviate the pain. Correspondingly, the horse steps under itself as far as possible with its hind legs to relieve the forelegs of weight. This results in the "squatting" body outline (hindquarters extremely lowered, forelegs flung very high) typical of the "big lick" horse. Such abuses are illegal under the Horse Protection Act of 1970 but are still practiced.
Measures have been taken to stop the practice, and many supporters of the Tennessee Walking Horse have organized to oppose soring. The HPA, created specifically to stop such practices and to monitor the Tennessee Walking Horse in particular, prohibits the use of soring agents. The Animal and Plant Health Inspection Service (APHIS), part of the USDA, is working with the industry to enforce the law. Tennessee Walking Horse organizations send designated qualified persons (DQPs) to shows to inspect the horses, and, as funding permits, APHIS sends federally employed veterinary medical officers to work with DQPs at some shows.