Mounting scientific evidence shows that the routine feeding of antibiotics to healthy farm animals (which occurs without a prescription) promotes development of antibiotic-resistant bacteria that can be transferred to people, making it harder to treat certain infections in humans. This "nontherapeutic" agricultural use of antibiotics is estimated to constitute the majority of antibiotics used in the U.S. each year. In addition, some therapeutic uses of antibiotics in agricultural animals – specifically, use in poultry of fluoroquinolones, a class of antibiotics that includes Cipro – also demonstrably contribute to antibiotic resistance affecting human health.

The American Medical Association, the American Public Health Association, the American College of Preventive Medicine, and the Ambulatory Pediatrics Association are among the health organizations that have endorsed H.R. 3804.

Although the Food and Drug Administration is theoretically empowered to withdraw agricultural antibiotics from the market under existing law, in practice the procedures for cancellation are so cumbersome that such withdrawals would take years or even decades.

To avoid these unacceptable delays, this bill amends the Food Drug and Cosmetic Act (FDCA) to directly withdraw approvals for nontherapeutic agricultural use of eight specific named antibiotics or classes of antibiotics. The covered antibiotics are penicillins, tetracyclines, macrolides (including but not limited to erythromycin and tylosin), lincomycin, bacitracin, virginiamycin, aminoglycosides, and sulfonamides. All are used in human medicine or are so closely related to human use drugs that they trigger cross-resistance.

The cancellations automatically take effect two years after the date of enactment unless, prior to that date, the antibiotic's producer demonstrates to a reasonable degree of certainty that nontherapeutic use of the drug does not contribute to development of resistance affecting humans.

The bill would ban only the nontherapeutic uses of the named drugs. Nontherapeutic use is defined as "any use of an antimicrobial drug in animals in the absence of disease, including use for growth promotion, feed efficiency, or routine disease prevention." By specifically targeting the nontherapeutic use of antibiotics, the bill properly allows for sick animals to receive treatment. The bill leaves farmers with many options including other nontherapeutic antibiotics that are not used in human medicine, as well as improved animal husbandry practices such as those utilized in Europe and on some U.S. farms. The National Academy of Sciences estimates that a ban on nontherapeutic antibiotics would raise meat prices by less than twenty cents per person per week.

In addition, if a nontherapeutic antibiotic that is now used only in animals (i.e., one that is not one of the 8 named antibiotics) also becomes potentially important in human medicine, the drug would be automatically restricted from nontherapeutic use in agricultural animals unless FDA determines that such use does not contribute to development of resistance affecting humans. An antibiotic is considered as becoming potentially important in human medicine if FDA issues an Investigational New Drug determination or receives a New Drug Application for the compound.

The bill would also presumptively ban use of fluoroquinolones in poultry. FDA proposed in October 2000 to ban this use, based on data showing increased fluoroquinolone resistance in certain bacteria that cause severe food poisoning in humans. Fluoroquinolones are a key drug for treating such illnesses. Currently only one manufacturer produces fluoroquinolones for poultry.