Lawmakers seek to curb antimicrobial use in livestock

Some federal lawmakers are calling for an end to what they say is the animal agriculture industry's overuse of antimicrobials, which they blame for contributing to a rise in antimicrobial resistance in humans.

Under the bipartisan legislation, infection-fighting drugs used "nontherapeutically" in livestock but important to human health would be phased out over a two-year period.

Massachusetts Sen. Ted Kennedy and Ohio Rep. Sherrod Brown introduced the Preservation of Antibiotics for Medical Treatment Act (S. 1460/H.R. 2932) on July 25 in the Senate and House, respectively.

The Democratic senator and Republican congressman proposed similar legislation last year, but the congressional session ended before the bills were acted on (see JAVMA, April 1, 2002, page 947).

"Nontherapeutic use" is defined in the bill as adding antimicrobials to animal feed or water in the absence of disease to promote growth, feed efficiency, weight gain, and for disease prevention or other routine use.

Drugs that would be phased out are any kind of penicillin, tetracycline, bacitracin, macrolide, lincomycin, streptogramin, aminoglycoside, sulfonamide, or other drug or drug derivative used in human medicine to treat or prevent infection.

The antimicrobials could still be used to treat sick animals. They could also continue to be used as growth promotants and to prevent disease if the drug manufacturers demonstrate within two years that such use poses no harm to human health.

"This legislation is essential in the face of mounting scientific evidence that the overuse of antibiotics in animal agriculture promotes the rise of antibiotic-resistant bacteria that can sicken people," said Tamar Barlam, MD, of the Center for Science in the Public Interest.

But restricting these drugs, especially those used to prevent disease, will ultimately harm animals and could lead to an unsafe food supply, says a coalition of food animal producer groups, veterinarians, and pharmaceutical companies.

The Coalition for Animal Health opposes the bills because they would ban drugs by categories of classes of use instead of through risk-based, individual drug-use species combination decisions, such as the decision process used by the Food and Drug Administration.

Moreover, the coalition, which includes the AVMA, AASV, and National Cattlemen's Beef Association, asserts that drug regulation and risk assessment are matters better handled by the FDA than by Congress.

"We believe that the regulation of antibiotics needs to be done on a scientific, risk assessment basis, not a political basis," said Ron Phillips of the Animal Health Institute, another coalition member. "The legislation banning products apart from scientific review carries with it the threat of unintended consequences."

At press time in August, the bills had been referred to committee.