Horse Meat Plant in New Mexico Faces Hurdle After Ruling on Drugs New Mexico's attorney general ruled on Monday that veterinary drugs commonly administered to horses would render their meat adulterated under state law, meaning it would not be fit for human consumption. The ruling created another headache for the Valley Meat Company, a plant in Roswell, N.M., that is on track to be the first horse slaughtering facility to open in the United States since 2007. "Our legal analysis concludes that state law does not allow for production of meat that is chemically tainted under federal regulations," Gary K. King, the state attorney general, said in a statement. New Mexico law is very clear that it would be prohibited and illegal. Horse slaughter was effectively banned in the United States in 2007, when Congress passed a provision that barred the Agriculture Department from spending any money to inspect horse meat. That provision had to be renewed annually, and in 2011, it was dropped from an omnibus spending bill that President Obama signed into law, opening the gate for horse slaughter to resume. The Obama administration has included a proposal in its 2014 budget that would reinstate the ban on horse meat for human consumption. Mr. King looked into the issue at the request of State Senator Richard C. Martinez, a Democrat from Espanola, N.M. Mr. Martinez had expressed concerns that Valley Meat might open "despite the fact that to do so may be in violation of New Mexico's laws that prohibit the manufacture of any food that is adulterated." In his formal opinion, Mr. King noted a 2010 study in Food and Chemical Toxicology, a scientific journal, that aimed to track 68 racehorses scheduled or sent to American and international slaughter plants between 2004 and 2008. The researchers examined the health records of 34 of those horses and found that all of them, including some that were slaughtered, had been dosed with phenylbutazone at points ranging from one week to four years from being killed. A. Blair Dunn, a lawyer representing Valley Meat, said the ruling would have no impact on the plant's plans to open. "We have an approved drug residue testing program that will be in place like the programs used for any other species," Mr. Dunn said. The Agriculture Department has a National Residue Program that tests for approved and illegal veterinary drugs, pesticide, hormones and other contaminants that may end up in meat, poultry and eggs. How that program would apply to horse slaughter remains to be seen. The Food and Drug Administration has set no safe level of phenylbutazone in animals intended for food and has banned administration of the drug to any horse sent for slaughter. The European Union also ban the use of the drug in such horses. "Yet this ban is being circumvented because there is no pre-slaughter mechanism to determine and remove horses that receive PBZ during their lifetimes," the 2010 study said, concluding that the gap in food safety was "a significant public health risk."