CHICAGO - The 7th U.S. Circuit Court of Appeals heard arguments Thursday but has not yet issued a ruling about the constitutionality of an Illinois law that bans horse slaughter in the state for human consumption - a law that could close the Cavel International facility in DeKalb. Owners of Cavel International filed the appeal after U.S. District Judge Frederick Kapala ruled July 5 that the Belgium-based business did not prove the new law was unconstitutional. Although Cavel had been closed after that ruling, the plant is allowed to operate while the appeal is being considered. Mary Welsh, who spoke on behalf of the Illinois Attorney General's Office, said the state made a rational decision to enact the ban as a way to protect horses, which are described in the legislation as “companion animals” not fit for human consumption. But Cavel attorney J. Philip Calabrese argued that the ban, which was signed into law May 24, violates foreign commerce laws. Cavel - the sole remaining horse-slaughtering facility in the country - exports all horse meat produced at the DeKalb plant to Europe and Japan, Calabrese said. Cavel accounts for less than 1 percent of all horse meat sales abroad, and therefore the plant's impact on commerce is minimal at best, U.S. appellate Judge Ilana Rovner said. “How can the law burden foreign trade except in a negligible way?” Rovner said. Rovner asked if the Cavel plant could be converted into a cattle slaughterhouse, as was done with a horse-slaughtering facility in Texas, but Calabrese said the DeKalb operation could not be retrofitted for any use other than processing horses. Chief U.S. appellate Judge Frank Easterbrook asked if the state planned on banning slaughter of other animals, before he questioned the legitimacy of the state's concern for animal safety. “The bill is a symbolic gesture to protect horses but does not include any actions of real welfare for animals,” Easterbrook said. U.S. appellate Judge Richard Posner asked what the overall effect would be if Cavel closed. Welsh said horse theft would go down, pointing out that Cavel buys most of its stock from auctioneers and brokers who do not question the origins of horses that are purchased. Posner demanded evidence to back the claim, which he said was not provided in the state's brief for the hearing. “People are only getting $300 when their horses are sold (to the plant),” Posner said. “The costs of transporting the horses to the plant cannot make the act profitable.” Two organizations - The Humane Society of the United States and the Animal Welfare Institute - each have filed a “friend of the court” brief in the appeal. Those briefs provide legal information in an advisory capacity, but the two organizations did not speak during Thursday's hearing. Tracy Silverman, an attorney with the Animal Welfare Institute, said after the hearing that the organization included information about horse theft in its brief in an attempt to cover ground that differed from the state's material. The brief includes two testimonies from people running horse rehabilitation and rescue organizations near Cavel. Both testified they have lost business because of horses reportedly being stolen to be sold to Cavel. Lawyers representing the attorney general's office are not permitted to comment on their cases. Benji Feldheim can be reached at firstname.lastname@example.org.