A Federal Court Judge in the United States has ordered the Food and Drug Administration (FDA) to commence the process of withdrawing its approval for the use of penicillin and tetracycline in livestock feed to promote animal growth.

The ruling by US Magistrate Theodore Katz last week compels the FDA to advise drug manufacturers that the popular antibiotics will be withdrawn for use in animal feed, unless the companies can prove they are safe.

The case was initiated by the Natural Resources Defence Council (NRDC), which has argued that giving antibiotics to livestock through animal feed increases the risk of superbugs and other drug-resistant bacteria.

The NRDC said the FDA’s own scientists found in 1977 that exposing healthy animals to low doses of penicillin, tetracycline and other drugs intended to cure human disease could encourage bacteria that are immune to the drugs to flourish.

At the time the FDA announced its intention to withdraw approval for some uses of penicillin and tetracyclines, however, the planned regulations were not enforced.

In his decision, US Magistrate Katz criticised the FDA not acting on the issue.

"For over thirty years, the FDA has taken the position that the widespread use of certain antibiotics in livestock for purposes other than disease treatment poses a threat to human health … the FDA never held hearings or took any further action on the proposed withdrawals.

“In the intervening years, the scientific evidence of the risks to human health from the widespread use of antibiotics in livestock has grown, and there is no evidence that the FDA has changed its position that such uses are not shown to be safe.”

The judge said research had shown that the use of antibiotics in livestock lead to the development of antibiotic-resistant bacteria that could be transferred from animals to humans through direct contact, environmental exposure, and the consumption and handling of contaminated meat and poultry products.

The National Cattleman’s Beef Association’s website says the US industry has adopted a policy of outlining the judicious use of antimicrobials which discourages the feeding of low levels of antibiotics to promote growth since 1987.

The policy recommends that producers avoid the use of antibiotics that are important in human medicine; use a narrow spectrum of antimicrobials whenever possible; treat the fewest number of animals possible and limit the use of antibiotics to the prevention or control of disease. The policy says antibiotics should not be used if the principle intent is to improve performance.

Following a report by the Federal Joint Expert Technical Advisory Committee on Antibiotic Resistance (JETACAR) in 1999, Australia’s livestock industry also instigated measures to prevent the use of antibiotics that are used in both animal and human medicines in Australia.

Australia’s livestock producers only used antibiotics as a therapeutic device, and only after animals became ill, Australian Lot Feeders Association executive director Dougal Gordon said.

“The use of antibiotics in animal agriculture in Australia is restrained,” he said.

“Work that has been done by organisations in Australia to determine the level of antibiotic load in agriculture and particularly livestock has indicated that the microbial level is really low.

“It is not an issue in Australia but we’re still none the less putting in place a number of mechanisms to reduce that level of load anyway.”