WITHDRAWN APPROVALS. “On September 30, 2013, FDA denied a petition from the Center for Food Safety and the Institute for Agriculture and Trade Policy that asked the agency to take steps to revoke the approvals of four arsenic-based animal drugs. The petitioners’ requests … became moot after the sponsors of those drugs requested that FDA withdraw the approvals for those products.”
http://www.fda.gov/AnimalVeterinary/SafetyHealth/ProductSafetyInformation/ucm370568.htm