If you'd like to read the draft document issued under the Center for Veterinary Medicine, here is a link to that as well as how to send in comments either online or by snail mail. The short story is this is part of the ongoing effort to make sure animal ag producers are using medically important antimicrobial products in a way that doesn't jeopardize human health.
Or as the CVM states: "The guidance contains information for sponsors of such new animal drugs to facilitate voluntary changes to the approved conditions of use of these drugs to prescription marketing status.
"On September 14, 2018, FDA unveiled a 5-year action plan for supporting antimicrobial stewardship in veterinary settings. This plan builds upon the important steps the Center for Veterinary Medicine (CVM) has already taken to support the judicious use of antimicrobials in animals, and is driven by the concept that medically important antimicrobial drugs should only be used in animals when necessary for the treatment, control, or prevention of specific diseases.
"One action item included in this plan is to ensure that any medically important antimicrobial new animal drugs that continue to remain available as OTC products are brought under the oversight of licensed veterinarians. The purpose of this guidance is to provide sponsors with specific recommendations on how to facilitate voluntary changes to the approved conditions of use of these drugs to prescription marketing status. The voluntary process outlined in this guidance will help to ensure new animal drugs containing antimicrobials of human importance are administered only under veterinary oversight and only for therapeutic uses."
Comments should be submitted by 12-24-2019.