Royal Canin U.S.A., Inc. v. Wullschleger

Anastasia Wullschleger (plaintiff) purchased dog food manufactured by Royal Canin U.S.A., Inc. (Royal Canin) (defendant). Royal Canin’s dog food was more expensive than other dog foods and was available only with a veterinarian’s prescription. However, Wullschleger later learned that Royal Canin’s dog food did not contain any medication that would differentiate it from ordinary dog food or otherwise justify the higher price. Wullschleger sued Royal Canin in Missouri state court, alleging claims under a state merchandising-practice act, state antitrust law, and the federal Food, Drug, and Cosmetic Act (FDCA). Royal Canin removed the case to federal court based on the FDCA claim, which fell under the district court’s federal-question jurisdiction. The removal also allowed the district court to exercise supplemental jurisdiction over Wullschleger’s related state-law claims. However, Wullschleger did not want to litigate in federal court. Accordingly, Wullschleger amended her complaint to delete her FDCA claim, leaving only the state-law allegations. Wullschleger petitioned for remand to state court, but the district court denied the request. The United States Court of Appeals for the Eighth Circuit reversed, concluding that Wullschleger’s amendment of her complaint left no basis for federal jurisdiction. Because other federal appellate courts had decided this issue differently, the United States Supreme Court granted certiorari to resolve the circuit split.