The Performance Show Horse Association (PSHA); SHOW, the horse industry organization (HIO) that manages the Tennessee Walking Horse National Celebration; and several other industry members have hired a law firm to request an investigation into USDA Veterinary Medical Officers (VMOs).

Veterinary medical officers are charged with enforcing the Horse Protection Act (HPA) of 1970, which forbids soring, the deliberate injury to a horse's feet and legs to achieve an exaggerated, high-stepping gait.

Documents provided by PSHA spokesman Phil Osborne indicate that the Tennessee Walking Horse industry groups, hired the Gray Plant Mooty law firm of to send a letter in early April to USDA Secretary Tom Vilsack. The letter, signed by Gray Plant Mooty attorney Phillip Kunkle, asked Vilsack to investigate VMOs on grounds that those officers allegedly apply HPA rules inconsistently. A statement on the PSHA website indicates that letter received no response.

An April 17 letter, also signed by Kunkle, was sent to the Office of the Inspector General (OIG) and the USDA's general council seeking an investigation into alleged “retaliatory” actions of VMOs during the 2012 show season. The letter also requests an investigation into “'announced changes” to the protocol of determining scar rule violations during the 2014 show season, despite no change to the existing HPA statute. That letter also calls for a probe into the alleged intimidation of designated qualified persons (non-government personnel trained and licensed to inspect horses for HPA compliance) by threatening them with letters of warning if they differed from VMO decisions in matters of scar rule findings. Finally, the April 17 letter seeks an investigation into the use of iris scanning horse identification technology on grounds that it allegedly allows VMOs to“target”animals that have received prior violations