As of Dec. 31, FDA is withdrawing approval for nitrasone, the last arsenic-based drug used to treat food-bearing animals. The drug is used to prevent blackhead disease in poultry and is used primarily with turkeys. FDA announced in April that Zoetis would phase out the drug by the end of 2015. “This strategy allows affected producers the opportunity to consider alternatives for managing this disease in the future,” said FDA. Scientific studies reported that an arsenic-based drug, roxarsone, resulted in higher levels of inorganic arsenic, a carcinogen, in the livers of chickens than in those not given the treatments. Sales of roxarsone were suspended in 2011. Blackhead is a seasonal disease in parts of the United States and causes a significant death rate in turkeys.