15 U.S.C. § 1822: Congressional statement of findings

the soring of horses is cruel and inhumane; horses shown or exhibited which are sore, where such soreness improves the performance of such horse, compete unfairly with horses which are not sore; the movement, showing, exhibition, or sale of sore horses in intrastate commerce adversely affects and burdens interstate and foreign commerce; all horses which are subject to regulation under this chapter are either in interstate or foreign commerce or substantially affect such commerce; and regulation under this chapter by the Secretary is appropriate to prevent and eliminate burdens upon commerce and to effectively regulate commerce.