The U.S. Food and Drug Administration (FDA) said that, since it announced final Guidance for Industry #213 in December 2013, all but one animal drug company have committed in writing to seek withdrawal of approvals for any production uses of affected drug applications and change the remaining therapeutic uses of their products from over-the-counter (OTC) to use by Veterinary Feed Directive (VFD) or prescription.

On December 11, 2013, the FDA announced the implementation of its plan to help phase out the use of medically important antimicrobials in food animals for food production purposes. FDA asked affected sponsors to notify the agency in writing within three months of their intent to engage with FDA as defined in Guidance #213.