A federal appeals court ruled Thursday that the U.S. Food and Drug Administration may continue its policy of allowing widespread antibiotic use in animal feed — a practice believed by many to contribute to the development of antibiotic-resistant bacteria, or superbugs.

In a 2-1 ruling, the U.S. Circuit Court of Appeals in New York said the FDA could reject two citizen petitions challenging the use of antibiotics such as penicillin and tetracyclines in feed for animals raised for human consumption, even when those animals are not sick. The decision Thursday is a reversal of a lower court ruling on a suit, filed by several consumer advocacy groups, that had called on the FDA to hold hearings reviewing new scientific evidence on the regular use of antibiotics in livestock feed.

Despite a 1977 declaration that the widespread use of antibiotics in animal feed was unsafe, the FDA in 2011 rejected the two citizen petitions and opted not to hold the hearings, either. But a district court in New York in 2012 ruled on behalf of the National Resources Defense Council, the Center for Science in the Public Interest and other groups that sued the agency, calling for a ban on use of antibiotics for food animals when they were not sick.

However, the federal appeals court said Thursday that it was up to the FDA, not the courts, to decide how to deal with the problem. “It is not for us to determine whether [the FDA] has been prudent or imprudent, wise or foolish, effective or ineffective in its approach to this problem,” the judges wrote in the majority opinion (PDF). “Whether the agency’s long inaction in the face of dangers highlighted in the [1977 FDA report] represented politically-inspired foot-dragging or wise caution in developing a cost-effective approach, it was for the agency, and not the courts, to determine how best to proceed.”

Many cattle, hog and poultry producers regularly give their animals low doses of antibiotics to prevent illness and make them grow faster.

However, doctors and scientists have warned in recent years about the emergence of superbugs — new strains of bacteria that are resistant to currently available antibiotics — and suspect that humans’ repeated exposure to meat that contained antibiotics may create those drug-resistant bacteria.

One superbug, CRE, has grown fivefold in hospitals and other health care centers in the Southeastern U.S. between 2008 and 2012, according to a study published Thursday. And the Centers for Disease Control and Prevention in 2013 estimated that more than 23,000 people die each year in the U.S. from such drug-resistant infections.

The FDA has been debating how to address the issue of antibiotics in meat for several years as consumers have become more aware of the issue, increasingly opting to buy antibiotic-free meat.

Last December, the agency asked drug companies to voluntarily stop labeling antibiotics that are important for treating human illnesses as acceptable for promoting growth in animals. The FDA said the new voluntary guidelines, which allowed companies three years to comply, would be faster and more efficient than making label changes mandatory — a complicated process that could take years.

By March 2014, 25 out of the 26 drugmakers that sell antibiotics used in livestock feed to enhance growth agreed to follow the FDA’s new guidelines. The companies included pharmaceutical giants Eli Lilly and Bayer.

Still, in his dissenting opinion, Judge Theodore Katzmann (PDF) wrote that the FDA was being allowed to “openly declare that a particular animal drug is unsafe but then refuse to withdraw the approval of that drug. It also gives the agency discretion to effectively ignore a public petition asking it to withdraw approval from an unsafe drug.”

“I do not believe the statutory scheme can be read to permit those results,” he added.

“The misuse of antibiotics in food animal production contributes to the epidemic of antibiotic resistance in our hospitals and communities,” Dr. Robert S. Lawrence, director of the Johns Hopkins Center for a Livable Future, said in a news release. “Today’s decision is deeply disappointing because it allows voluntary guidelines to take the place of decisive action in confronting one of the most important public health problems of our time.”