The US is to ban the use of antibiotics in feed for animals for production purposes such as feed efficiency and growth promotion, the US Food and Drug Administration (FDA) has announced.

The move will bring the use of these drugs under veterinary supervision so that they are used only when necessary for assuring animal health, the FDA says.

Once the changes are implemented, it will be illegal to use these medically important antibiotics for production purposes, it says.

Farmers will need a prescription from a licensed vet to use antibiotics for prevention, control or treatment of a specifically identified disease.

The Veterinary Feed Directive (VFD) final rule outlines the process for authorising use of VFD drugs (animal drugs intended for use in or on animal feed that require the supervision of a licensed veterinarian) and provides veterinarians in all states with a framework for authorizing the use of medically important antimicrobials in feed when needed for specific animal health purposes, the FDA says.

In the case of disease prevention, the FDA says it is important such use is appropriately targeted to animals at risk for a specific disease and the use duration is limited and risk-based.

The FDA says it has examined the approved labels for medically important antibiotics used in feed and water and has identified that, on approximately 30% of the labels, there is at least one use that does not specify how long the drug should be used.

The Animal Drug Availability Act of 1996 (ADAA) amended the Act to establish a new category of drugs, veterinary feed directive (VFD) drugs, the FDA says.

A drug approved for use in or on animal feed as a VFD drug is limited to use only under the professional supervision of a licensed veterinarian, it says.

Michael R. Taylor, FDA Deputy Commissioner for Foods said that the actions the FDA has taken to date represent important steps toward a fundamental change in how antimicrobials can be legally used in food-producing animals.

“The VFD final rule takes another important step by facilitating veterinary oversight in a way that allows for the flexibility needed to accommodate the diversity of circumstances that veterinarians encounter, while ensuring such oversight is conducted in accordance with nationally consistent principles,” he said.