Those who use chemical numbing and masking agents on horses to hide evidence of soring would face felony charges under the Horse Protection Act (HPA) if the United States Department of Agriculture (USDA) acts on a legal petition the Humane Society of the United States (HSUS) filed this week.

The HPA prohibits soring, the use of chemicals or other devices to deliberately injure horses’ legs or feet to produce an exaggerated high-stepping gait. The USDA’s Animal and Plant Inspection Service (APHIS) enforces the Act. Attempts to interfere with inspections to determine whether a horse has been sored are also forbidden under the Act. As a result, the USDA/APHIS bans several chemical substances that might be used to numb horses’ limbs or mask other signs of soring under its Horse Protection Program. Among those substances are menthol, which acts as a numbing agent, and vitamin E, which can mask soring-related scarring.

However, Keith Dane, HSUS’s director of Equine Protection, said that according to results of USDA/APHIS random testing for banned substances at high-profile Tennessee Walking Horse exhibitions, including the 2011 National Celebration and the 2011 National Trainers’ Show, banned substance use is widespread. As a result, the HSUS has submitted a legal petition asking the USDA to issue a new rule or establish a policy that treats as a felony offense any use of banned substances to avoid the detection of underlying soring. The petition also asks that all banned-substance use cases be referred to the U.S. Attorney’s Office for prosecution.

Teresa Bippen, vice president of Friends of Sound Horses (FOSH), said the vigorous prosecution of illegal chemical use on horses is "much needed in an industry that refuses to comply with the Horse Protection Act