After decades of discussion by the US Food and Drug Administration about how and when to best manage the use of antibiotics in animals, recent legislation in California demonstrates that some states have decided to move forward with legislation more rapidly than required by the federal government’s guidance for “judicious use of antimicrobials in food-producing animals”.

While the FDA has received engagement of drug manufacturers who produce medically important antibiotics for use in animals, manufacturers have until the end of 2016 to fully comply with the FDA’s guidance. The federal strategy is based on changing the use of antibiotics in food-producing animals from products that can be used without prescriptions, without oversight by veterinarians, and for purposes beyond pathogen burden such as for growth promotion to use based on need and under the direction of a veterinarian. Up to now, many products have been available to animal producers over-the-counter and have often been included as a component in feed for animals as a growth supplement.

The science between the use of antibiotics in animals and the emergence of antibiotic resistance across the animal kingdom is becoming increasingly clear, and has become a driver behind the effort to control the use of antibiotics in animals. As has been reported recently, approximately 80% of antibiotic use in the United States is for use in livestock and poultry, rather than humans. Yet according to published reports by the federal Interagency Task Force on Antimicrobial Resistance, “[t]he extensive use of antimicrobial drugs has resulted in drug resistance that threatens to reverse the medical advances of the last seventy years.” Addressing these concerns inevitably leads to consideration of how best to preserve the use of medically necessary antibiotics and slow the emergence and spread of antibiotic resistance.

Given the difficulty to control antimicrobial resistant infections in the human population and the growing cost treatment, some states are now working to supplement and accelerate the activities of the FDA. On October 10, California became the first state to ban the indiscriminate use of antibiotics in animals. Under the new law, food-producing animals will only be able to receive antibiotics under treatment by a veterinarian when the animal is sick, or when there appears to be an "elevated risk" for infection.

Other states also have a history of considering actions to enact legislation aimed at limitations on the use of such antimicrobial drugs. For example, in the past three years legislation introduced in Maryland sought to limit the sale of commercial feed or drinking water containing antimicrobial drugs in order to limit the spread of exposure to antimicrobials beyond those animals in therapeutic need.

Similarly, legislation introduced in New York and Minnesota sought to prohibit the non-therapeutic use of antimicrobial drugs in food-producing animals and also to prohibit the sale of food-producing animals, if antimicrobials have been used in a non-therapeutic setting. New Jersey's approach was less committal in its legislative language but expressed support for federal action to limit antibiotic use in food-producing animals and does support a ban of non-therapeutic use of antibiotics in livestock. North Carolina introduced a bill to study and require reporting on the in-state use of antibiotics in food-producing animals.

The trend continued this year as Oregon saw legislation proposing to prohibit the routine administration of antibiotics for both growth promotion and disease prevention, although providing farmers discretion to preventatively treat herd outbreaks. The legislation, which did not make it out of the session (although its author intends to re-introduce it in 2016) also would require the largest operations to publicly disclose their antibiotics use. In the eastern U.S., Pennsylvania has seen the recent re-introduction of a fairly extensive bill prohibiting administration of specified antimicrobial agents, and allowing for inspection, testing, reporting and enforcement in regard to antibiotic use in animal production facilities, while West Virginia saw the introduction of a bill to prohibit the use of non-therapeutic feeding of antibiotics to food-producing animals (although that legislation had not yet been enacted at the time the session adjourned).

In each instance, legislation demonstrates the varied approach that states may take in adopting or accelerating efforts aimed at limiting indiscriminate antibiotic use in animals and poultry. Oftentimes, the approach seems to favor a veterinarian-client-patient relationship prior to use of medically important antimicrobials in food producing animals, livestock and poultry. As states continue to evaluate the impact of the federal guidelines, we anticipate that states will continue to revise the condition of use for medically important antimicrobials from over-the-counter availability to veterinary feed directives or veterinary prescription based applications.