The U.S. Food and Drug Administration (FDA) has announced a plan to phase out certain antibiotics used in meat production.

Antibiotics are often added to the food or water and given to commercial "cattle, hogs, poultry and other food-producing animals" to make them grow faster. They can also cause animals to grow with less feed and nutrition, an FDA news release reported.

Overusing antibiotics can be problematic because the practice promotes dangerous mutations that lead to antimicrobial resistance. This type of resistance has been called a "major threat to public health," according to the news release.

The FDA is going to take action against using "medically important" drugs for routine use in hopes of preventing a scenario in which those antibiotics are no longer effective in treating humans.

"We need to be selective about the drugs we use in animals and when we use them," William Flynn, DVM, MS, deputy director for science policy at FDA's Center for Veterinary Medicine (CVM), said. "Antimicrobial resistance may not be completely preventable, but we need to do what we can to slow it down."

The FDA issued a final guidance document for animals pharmaceutical companies that urges them to voluntarily remove approval for growth enhancement and feed efficiency indications to be used when not medically necessary. They also ask that some of these antimicrobials be stripped of their over-the-counter status and be available only under veterinarian supervision.

If the industry agrees to make these changes the antibiotics will be used for only "medically important" applications.

The FDA first suggested a strategy to phase out antibiotic use in non-medically-important situations in 2010; the newly released guide marks the beginning of the implementation period.

"This action promotes the judicious use of important antimicrobials, which protects public health and, at the same time, ensures that sick and at-risk animals receive the therapy they need," CVM Director Bernadette Dunham, DVM, Ph.D., said. "We realize that these steps represent changes for veterinarians and animal producers, and we have been working to make this transition as seamless as possible."

American pharmaceutical companies are being asked to notify the FDA of their intent to follow the guidelines within the next three months.

"Based on our outreach, we have every reason to believe that animal pharmaceutical companies will support us in this effort," Michael R. Taylor, FDA's deputy commissioner for foods and veterinary medicine, said.