Cattle, hogs and other livestock should be given antibiotics only when medically necessary, to avoid overuse that can foster drug resistance, the U.S. Food and Drug Administration said Wednesday.
The FDA said it wants to phase out production uses of antimicrobials, including for weight gain and accelerated growth, and phase in veterinary oversight of the remaining uses of such drugs. Farmers now can purchase some of the drugs over the counter.
Even though producers will need prescriptions for the antibiotics, they aren't bound by the new guidelines to restrict nonmedical uses of the drugs.
Cattle and hog producers say they're already careful about how they use antibiotics.
"Pork producers use antibiotics judiciously because they're not needed all the time and they're expensive," said Ron Birkenholz of the Iowa Pork Producers Association. "They only use them when they absolutely have to."
In some instances, Birkenholz said, antibiotics are used to promote growth.
Anne Burkholder, who runs a 3,000-head cattle feed yard near Cozad, Neb., said she doesn't use antibiotics to promote growth. "It is not often used that way in the beef industry," she said. "That's not to say it never is."
An estimated 80 percent of all antibiotics sold in the United States wind up on animal farms. Neither industry nor the government track what percentage of those drugs is used to boost animal weight.
The FDA is taking the action, officials said, because it is "well-established scientifically that all uses of antimicrobial drugs, in both humans and animals, contribute to the development of antimicrobial resistance."
The FDA's recommendations are a good start, said Dr. Trevor VanSchooneveld, an assistant professor of infectious disease at the University of Nebraska Medical Center. "The problem is it's totally voluntary. It's sort of asking people to do the right thing. ... What's really needed is not using antimicrobials as growth promoters."
Last month, a federal judge ordered the FDA to take action on its own 35-year-old rule that would have banned nonmedical use of two popular antibiotics, penicillin and tetracycline, in farm animals. The FDA issued the rule in 1977 but never enforced it, following vigorous pushback from members of Congress and lobbyists.
Four public safety groups sued the agency to act on the regulation, winning the case handed down in the U.S. District Court of Southern New York on March 22. The agency was given 60 days to appeal.
Mike Taylor, FDA's deputy commissioner for foods, said he thinks the voluntary guidelines can achieve the same goal as the court ruling in less time.
The FDA said a formal ban on certain uses of antimicrobials would have required individual hearings for each drug, which could take decades.
"The process we would have to go through is a formal hearing process, product by product, that is extremely cumbersome," Taylor said. "There's no point in going through those legalistic proceedings when companies are willing to make this shift voluntarily."
Taylor said the FDA has consulted closely with drugmakers and expects them to support the measures.
After three years, the FDA said, it intends to evaluate the voluntary adoption of the proposed changes. It then will consider further action as warranted.
Burkholder, who spoke Wednesday at a seminar on beef quality assurance in Washington, D.C., said it's important to note that the FDA is talking about antibiotic resistance, not antibiotic residue in food.
Antibiotic resistance, she said, means that a sick animal would be administered an antibiotic but the microorganism inside the animal wouldn't be killed off and would become resistant to the antibiotic. The bug, she said, then would have to replicate enough so that it starts to affect the animal and then jump from the animal to humans.
The FDA says that if resistant bacteria enter the food supply, drugs normally used to treat people infected with those bacteria may not work.
Food-borne outbreaks from pathogens that are resistant to antibiotics have sickened 19,897 people and killed 26 between 1973 and 2009, according to the Center for Science in the Public Interest, a Washington-based consumer advocacy group.
Burkholder said the proper use of antibiotics matters to her both as a mother and as someone who takes care of cattle.
"I think it's important for folks to realize how many other things I do every day to make sure my animals stay healthy," she said, "and they don't have anything to do with antibiotics."
This report includes material from Bloomberg News and the Associated Press.