Antibiotic Use in Food Animals – How this Practice Affects Everyone

By Rachel Fischer, MD, MPH, Integrative Therapeutics distinguished professor

On April 6, 2015, the Oregon Senate Committee on Health Care heard testimony from a number of concerned citizens and organizations regarding a bill that seeks to limit the non-therapeutic use of antibiotics in Oregon livestock and poultry. Because of my previous involvement in this issue through Health Care Without Harm, I was one of several people giving testimony in favor of Senate Bill 920 — Relating to protecting antibiotics for human public health; declaring an emergency.

Essentially, this bill:

  • Prohibits giving antibiotics to healthy farm animals in Oregon. The measure has exceptions for when there is a significant need to control an outbreak.
  • Requires disclosure of how antibiotics are used on factory farms. The bill will require EPA-defined Concentrated Animal Feeding Operations (CAFOs) to annually disclose the details of their antibiotic use and make that information public record.

Why is this law necessary?

Organ transplant, chemotherapy and common surgical procedures like a cesarean section and appendectomy – these are just a few of the medical treatments that would no longer be safe without the use of antibiotics. The problem is that resistance to every antibiotic we use is growing. According to Dr. Tom Frieden, director of the CDC, “antimicrobial resistance is happening in every community, in every health care facility, and in medical practices throughout the country. At least two million people per year in the U.S. get infections that are resistant to antibiotics, and 23,000 die.” And considering that drug makers developed about 20 new classes of antibiotics between 1940 and 1962, but only two new classes since then, our arsenal is diminishing.

Most physicians and patients recognize that antibiotics are over prescribed. The Centers for Disease Control and Prevention estimate that this is true up to 50 percent of the time. However, even if prescribing practices by providers and antibiotic use by patients was perfect, the issue of growing antibiotic resistance would not be solved.

An estimated 80 percent of antibiotics sold in the U.S. are for food animal production. Many classes of the antibiotics used for this purpose are also medically important for treating human disease. Most of our meat comes from CAFOs where animals are housed in very tight and unsanitary quarters which creates an ideal bacterial breeding ground. Of course, antibiotics are given to sick animals, but an equally common practice is to routinely give subtherapeutic doses of antibiotics for growth promotion and to prevent infection. In this scenario, antibiotics seem necessary to maintain our food supply. However, even if that were true, it ignores the perhaps more catastrophic consequences of continuing on the current path of antibiotic use.

One of the reasons bacteria are so resilient (they have, after all, essentially existed on earth since the beginning of time) is that they can easily exchange genetic material with or without breeding. That means a perfectly harmless bacterium species can develop antibiotic resistance and pass that resistance on to a more virulent, harmful species. When millions of food animals receive subtherapeutic antibiotics every day, one can only imagine the downstream effects:

  • Bacteria carrying resistance genes outlive those without resistance and continue to multiply;
  • Resistance genes are passed among bacteria living in the surrounding soil, in the animals and on the farm workers;
  • Farm workers inadvertently share their bacteria with their families and communities;
  • Food animals are transported on our highways when it’s time for slaughter, literally “spraying” bacteria in their path;
  • Animal waste from CAFOs is used to fertilize crops, further spreading bacteria carrying resistance genes – even to those who never consume meat; and
  • Mature crops carrying antibiotic resistant bacteria are sold directly to markets and for packaged food production.

During 2010 Congressional testimony, the FDA, USDA and CDC reported there is a definitive link between routine, non-therapeutic use of antibiotics in food animal production and the antibiotic resistance crisis in humans. And there is another often overlooked consequence of this practice that we are just beginning to comprehend – how environmentally pervasive antibiotics and resistance genes affect the human microbiome.

The human body is composed of about 30 trillion human cells, but is host to more than 100 trillion bacterial and fungal cells. Our bacteria and their DNA play a fundamental, essential role in human health. Antibiotics significantly impact our microbial diversity and have been linked to chronic diseases such as obesity. In his book, “Missing Microbes,” Dr. Martin Blaser states that our bodies are an ecosystem “much like a coral reef or tropical jungle, a complex organization composed of interacting life forms. As with all ecosystems, diversity is critical …. High diversity affords protection to all species within the ecosystem because their interactions create robust webs for capturing and circulating resources. Loss of diversity [can lead] to disease or collapse of the system.”

While some say it is not economically feasible to limit antibiotic use in order to maintain our food supply, experts agree it will likely be economically catastrophic in unmeasurable ways if we do not take steps to stop the non-therapeutic use of antibiotics in all forms. Dr. Blaser cites game theory and the “Nash Equilibrium” to shed light on the phenomenon of cooperation in regards to our relationship with bacteria, “It can be summarized as a strategy in a game with two or more players in which the outcome is optimized by playing within the rules; if you cheat, your outcome is worse than if you played fair and square.” Allowing unchecked use of antibiotics is cheating the game.

To email your local representative and the governor, readers can go to the Oregon State Public Interest Research Group website: Take Action with OSPIRG


SB 920 passed the Senate Health Care Committee and went to the Rules Committee. Unfortunately, no action was taken by the Rules Committee before the 2015 legislative session ended.  Antibiotics is a major issue and a repeat bill will likely appear next year.  No other state has passed legislation restricting non-medical use of antibiotics in food animals.  This may be a long fight, but the evidence continues to build in favor of such measures. Plus, Obama recently released his federal action plan to combat the growth of antibiotic resistant bacteria.

Want to learn more, read the OSPIRG fact sheet!

National Summary Data, Antibiotic Resistance