Since the 1940s, antibiotics have played a critical role in protecting public health, and have saved millions of lives. However, the non-therapeutic use of antibiotics by the modern food animal industry is now responsible for the emergence of drug-resistant bacteria that pose a grave threat to public health.

A push in the communities of public health, science and consumer advocacy is happening to end the inappropriate use in livestock production of drugs that are medically important for people. 1 Yet so far, most reforms have been the result of voluntary changes by the industry.

Antibiotics and Antibiotic-Resistance

Bacteria are everywhere and are vital to the proper functioning of our bodies. In fact, humans have roughly an equal number of bacteria to human cells. 2 However, while most bacteria are beneficial to and synergistic with human health, some cause serious illnesses and death.

Since their discovery in the early twentieth century, antibiotics, or antimicrobials, have been used to cure a wide range of bacteria-caused diseases including pneumonia, meningitis, syphilis, food poisoning, ear and skin infections and many others. Drugs, such as penicillin, tetracycline, amoxicillin and others, kill or inhibit the growth of bacteria without causing significant harm to people.

Misuse of antibiotics, however, leads to evolution of antibiotic-resistant bacteria, which render these powerful, life-saving drugs ineffectual and therefore obsolete. When bacteria are continually exposed to low doses of an antibiotic, those resistant to the drug survive and reproduce while the rest die off, resulting in a new bacteria population that resists the antibiotic. 3

Prescription of antibiotics to treat conditions caused by viruses like the cold or flu (which cannot be treated this way) and patients’ failure to complete their antibiotic regimen are two common examples of antibiotic misuse, which enable the appearance of new, resistant strains. 45 In hospitals, poor infection controls, lax hygiene and sanitary practices and the lack of rapid laboratory tests can all contribute to the spread of antimicrobial resistance. 6

Antibiotics and the Animal Industry

Nowhere are antibiotics used more widely and subject to less oversight than in the livestock industry. According to the FDA, more than 20 million pounds of medically important antibiotic drugs were sold for use in food producing farm animals in 2014 — that’s up to 80 percent of all antibiotics sold. 7 The notion of administering antibiotics to people on a daily basis would never be considered, let alone condoned.

Antibiotics have been used in livestock feed since the 1940s, when studies showed that the drugs caused animals to grow faster and put on weight more efficiently, increasing meat producers’ profits. 8 Up until the recent past, when the FDA banned the practice, non-therapeutic antibiotics — those used for purposes other than treating disease — were routinely given to livestock, poultry and fish on industrial farms to promote faster growth. 9 The medication has the added benefit to producers of preventing disease that would otherwise be caused by the crowded, unsanitary conditions in which the animals are raised; the FDA’s ban of antibiotic use in animals for growth promotion means very little when antibiotics are still allowed for disease prevention, a practice common in confined animal feeding operations (CAFOs), or factory farms. According to the FDA, from 2009 through 2014, domestic sales and distribution of antibiotics approved for use in food producing animals increased by 22 percent. 10 Further, 97 percent of these drugs were purchased over the counter, without any veterinary involvement or oversight, and administered to animals primarily through feed or water, which makes precise dosing impossible. 11 While the 2013 FDA rule (that went into effect in 2017) includes provisions for veterinary oversight of antibiotic administration, many – including several US Senators – worry the FDA “may lack the authority to ensure veterinarians adhere to the criteria.” 12

As industrial farming has spread around the world, so, too, has the use of non-therapeutic antibiotics. One study estimates that global antimicrobial consumption will grow by 67 percent by 2030, due to increasing demand for animal-based products, with countries including Brazil, India and China doubling their usage over that time period. 13 According to the World Health Organization, antibiotic-resistance in many areas of the world already exceeds 50 percent in many major bacteria groups, including E. coli, K. pneumonia and S. aureus. 14

Bacteria on the Farm Do Not Stay on the Farm

Research has shown that disease-causing bacteria are more likely to develop in industrial livestock facilities than in small or backyard livestock farms. 15 These bacteria can infect people through human contact with animals, food, the environment or other people. In the US, as in much of the world, there is little regulation of work conditions or worker exposure in concentrated animal feeding operations (CAFOs). The conditions in these high-density animal houses provide many opportunities for worker infection and the spread of infection to others in the community. Increased bacterial and viral pathogen exposure and infections have been reported among farmers, their families and farm workers at industrial poultry and swine operations as compared to control populations. 16 Workers at these facilities often carry (unknowingly) antibiotic-resistant bacteria into the general public; as one example, MRSA, a now-common staph bacteria resistant to many antibiotics, has been found to persist in the nasal passages of workers at industrial hog operations, even following extended periods away from these facilities. 17

Manure is a major vector by which antibiotics and antibiotic-resistant bacteria enter the environment, contaminate water and spread to residential areas. 18 Industrial livestock operations produce a tremendous amount of animal waste – 369 million tons in 2012, almost 13 times more than that of the 312 million people living in the US – and while human waste is treated at municipal treatment plants or by other means, there are very few regulations for animal waste and disposal, and no specific requirements for treatment. 1920 Most waste from animal confinements is stored in ponds (called lagoons) and ultimately applied untreated as fertilizer to farm fields. Bacteria can survive in untreated and land-disposed farm animal waste for two to twelve months; it is estimated that animals do not digest approximately three-quarters of the actual antibiotics, which then also necessarily pass from the animals into the environment. 2122

With huge quantities of manure routinely sprayed onto fields surrounding CAFOs, both antibiotics and antibiotic-resistant bacteria can leech into surface and ground water, contaminating drinking wells and endangering the health of people living close to large livestock facilities. 23

Bacteria do not simply travel on people or in water; numerous studies have also found high levels of antibiotics and antibiotic-resistant genes in air samples downwind of feedlots in dry regions, as well as bacteria in dust in industrial livestock barns that had survived for more than 20 years. 24252627 A Johns Hopkins University study found that many flies near broiler poultry operations carried antibiotic-resistant bacteria strains, making insects, according to another study, “a direct and important link between animal farms and urban communities for antibiotic resistance traits.” 2829


people die each year from antibiotic-resistant infections

Antibiotic Resistance and Public Health

Antibiotic-resistant bacteria are a growing public health crisis. Infections from resistant bacteria are increasingly common and are becoming ever more difficult and expensive to treat. The Centers for Disease Control (CDC) estimates that each year in the US, at least 2 million people acquire antibiotic-resistant bacterial infections and 23,000 people die as a direct result. 30 Health care costs associated with antibiotic-resistant bacteria amount to about $20 billion each year in the US alone, with an additional $25 million lost due to societal costs and over eight million extra patient days in the hospital. 31 A 2014 study by the Review of Antimicrobial Resistance, convened by the UK Prime Minister, estimates that by 2050, if nothing is done to curb antibiotic misuse, resistant bacteria will kill 10 million people a year – that’s more than are killed by cancer today – and will cost the global economy $60 trillion to $100 trillion. 32

Dr. Margaret Chan, the Director-General of the World Health Organization (WHO), released a statement on World Health Day 2011 about the bleak future for treating bacterial infections if no steps are taken to slow the development of antibiotic resistant bacterial strains. She warned: “[I]n the absence of urgent corrective and protective actions, the world is heading toward a post-antibiotic era, in which many common infections will no longer have a cure and, once again, kill unabated.” 33 WHO released the first-ever report on global antibiotic resistance in 2014, outlining the serious threat antibiotic-resistant bacteria present to public health around the world. 34

Efforts to Curtail Antibiotic Resistance

In the US, policy and regulatory action to curb antibiotic overuse by livestock producers has not kept pace with the urgency of the looming public health threat. The Food and Drug Administration (FDA) has issued guidance to industry to reduce the use of non-therapeutic use of antibiotics. The FDA implemented the Veterinary Feed Directive (VFD) and Guidance for Industry #213 in late 2015 and early 2017, respectively, to make more medically-important antibiotics subject to veterinary oversight and prohibit use of the drugs for production purposes, such as growth promotion rather than for strictly medical uses. The new rules make some important changes, but critics say they do not go far enough. In particular:

  • The VFD requested that manufacturers of animal drugs voluntarily revise the approved uses for their antibiotics. 35 Critics charge that voluntary changes leave the industry in the driver’s seat and relinquish government’s critical role in protecting citizens’ health and safety.
  • The VFD does not clearly define the terms of the veterinarian-client relationship, allowing for possible abuse, and does not set strict limits on duration or refills of prescribed drugs.
  • Guidance #213 continues to allow use of antibiotics for “disease prevention” not targeted towards a specific disease, and does not include defined and limited time frames for use. This allows producers to continue routine antibiotic use or use over multiple production periods on entire herds or flocks, under the guise of disease prevention. 36 

Preservation of Antibiotics for Medical Treatment Act

Representative Louise Slaughter (D-NY), the only microbiologist in Congress, has introduced the Preservation of Antibiotics for Medical Treatment Act (PAMTA) several times in the House of Representatives, most recently in the 2015-2016 session. 37 First introduced in 1999, the bill would phase out the non-therapeutic use of eight classes of medically important antibiotics and restrict the use of many other antibiotics in animal feed, while allowing the use of these drugs for treating sick animals. The prior time it was introduced, the bill had 78 Congressional cosponsors and was endorsed by 450 health, farming, food safety, religious, labor and consumer advocate groups. Fifty cities around the country have passed resolutions encouraging the passage of PAMTA and its Senate corollary, the Prevention of Antibiotic Resistance Act. Nonetheless, the bills have never made it out of committee. 38

World Health Organization Plan

In 2015, United Nations member states approved a World Health Organization plan to address antibiotic resistance, calling on countries to draw up action plans within two years. 39 The plan focuses on the development of better surveillance of resistance, prevention of infections, improved control over the use of existing antibiotics and support for investment in new drug development.

Responsible Use of Antibiotics in Agriculture

Ending the routine use of antibiotics in animal agriculture is critical for maintaining the ongoing efficacy of drugs that have saved many millions of lives. It is also possible and economically feasible. Feed containing growth-promoting antibiotics (GPAs) is more expensive than feed without antibiotics; a groundbreaking 2007 study by Johns Hopkins University researchers showed that the increased sale price of chickens fed antibiotics did not make up for the increased feed costs. 40 This is largely because GPAs have become less effective since the early 2000s; a 2014 study estimated that their use improved output for hog producers raising the animals from birth by a mere one percent – which is statistically insignificant. 41

Several studies of the market-level effects of a ban on GPAs in US hog and broiler chicken production indicate limited negative impacts: the quantity produced would, at most, decrease by 1.08 percent in the hog industry and 1.12 percent in the broiler industry, and the resulting increase in wholesale prices would range from less than one percent to at most two percent. 42 A recent study shows that banning GPAs in Denmark led to little more than a one percent drop in production of pork and only a slight rise in poultry production, which was offset in part by eliminating GPA costs; a ban in the US would likely produce similar results. 43 Given these negligible impacts to the industry and the potentially catastrophic human and economic costs of a “post-antibiotic” world, it is imperative that governments and industry take swift action to curtail overuse of these critical drugs.

Farmers who raise animals on pasture with sustainable practices do not use antibiotics for growth promotion or other non-therapeutic reasons. In part, they do not need the disease prevention aspects of the drugs, because the animals are raised in cleaner environments than those of confinement operations, with less stress and the ability to express natural behaviors, and thus are less prone to sickness. Generally, these farms use antibiotics only to treat acute infections in sick animals, just as they are used to treat human illness.

Animal Welfare Approved, a label certifying high animal welfare standards on livestock farms, includes standards for antibiotic use:

  • To help eliminate or reduce vulnerability to disease and the need for antibiotics at therapeutic levels, Animal Welfare Approved encourages the appropriate use of vaccines on an individual or group basis for prevention of disease.
  • Any sick or injured animals on the farm must be treated immediately to minimize pain and distress. This must include veterinary treatment if required. Recommended Homeopathic, herbal or other non-antibiotic alternative treatments are preferred. If alternative treatments are not suitable or not effective or if a veterinarian has recommended antibiotic treatment, this must be administered.
  • Animals treated with an antibiotic must not be slaughtered or used to produce milk for the Animal Welfare Approved program before a period of time has passed that is at least twice the licensed withdrawal period of the antibiotic used. 44

USDA organic standards prohibit antibiotic use in animals raised organically; if a sick animal is given antibiotics to treat infection, its meat or other products cannot be sold as organic. 45 The USDA also states that meat and poultry may carry the label “no antibiotics added” if the producer can demonstrate that the animals were raised without antibiotics. 46  The label “no routine antibiotic use” generally indicates that the animal was raised without use of non-therapeutic antibiotics, but may have been given antibiotics to treat illness – but there is no official definition of the term by government or third-party certifiers.

What You Can Do

You can help curb the systemic spread of antibiotic-resistant bacteria by supporting meat and poultry that has been raised without non-therapeutic antibiotics:

Hide References

  1. Marshall, Bonnie and Levy, Stuart. “Food Animals and Antimicrobials: Impacts on Human Health.” Clinical Microbiology Reviews, 24(4): 717-733 (2011). Retrieved January 13, 2017, from 
  2. Sender, Ron et al. “Revised Estimates for the Number of Human and Bacteria Cells in the Body.” PLoS Biol 14:8 (2016). Retrieved January 13, 2017, from
  3. World Health Organization. “Antimicrobial resistance: Fact sheet.” WHO, February 15, 2018. Retrieved January 13, 2017, from
  4. Mayo Clinic. “Antibiotics: Are you misusing them?” Mayo Clinic, 2014. Retrieved January 13, 2017, from
  5. Kohanski, Michael. “Sublethal antibiotic treatment leads to multidrug resistance via radical-induced mutagenesis.” Molecular Cell, 37(3), 311-320 (2010). Retrieved January 13, 2017, from
  6. World Health Organization. “Antimicrobial resistance.” WHO, February 15, 2018. Retrieved April 19, 2019, from
  7. Center for Veterinary Medicine. “SUMMARY REPORT on Antimicrobials Sold or Distributed for Use in Food-Producing Animals. FDA Department of Health and Human Services, December 2015. Retrieved January 13, 2017, from
  8. Dibner, JJ and Richards, JD. “Antibiotic Growth Promoters in Agriculture: History and Mode of Action.” Poultry Science, 84: 634–643. Retrieved January 13, 2017, from
  9. US Department of Health and Human Services. “FDA Announces Implementation of GFI #213, Outlines Continuing Efforts to Address Antimicrobial Resistance.” US Food and Drug Administration, 2017. Retrieved May 31, 2018 from:
  10. Center for Veterinary Medicine. “SUMMARY REPORT on Antimicrobials Sold or Distributed for Use in Food-Producing Animals. FDA Department of Health and Human Services, December 2015. Retrieved January 13, 2017, from
  11. PEW Charitable Trusts. “FDA Poliilces on Antibiotic Use in Food Animals.” PEW, May 6, 2016.  Retrieved January 13, 2017, from
  12. Warren, Elizabeth et al. “United States Senate Letter.” United States Senate, December 15, 2014. Retrieved May 31, 2018 from
  13. Van Boeckel, Thomas P. et al. “Global trends in antimicrobial use in food animals.” Proceedings of the National Academy of Sciences. vol. 112 no. 18: 5649-5654 (May 5, 2015). Retrieved January 13, 2017, from
  14. World Health Organization. “Antimicrobial resistance: global report on surveillance 2014.” WHO, April 2014. Retrieved January 13, 2017, from
  15. Graham, Jay P. et al. “The Animal-Human Interface and Infectious Disease in Industrial Food Animal Production: Rethinking Biosecurity and Biocontainment.” Public Health Report, 123(3): 282–299 (May-June 2008). Retrieved January 13, 2017, from
  16. Ibid.
  17. Nadimpalli, Maya et al. “Persistence of livestock-associated antibiotic-resistant Staphylococcus aureus among industrial hog operation workers in North Carolina over 14 days.” Occupational and Environmental Medicine, 72(2). Retrieved January 13, 2017, from
  18. Graham, Jay P. et al. “The Animal-Human Interface and Infectious Disease in Industrial Food Animal Production: Rethinking Biosecurity and Biocontainment.” Public Health Report, 123(3): 282–299 (May-June 2008). Retrieved January 13, 2017, from
  19. Food & Water Watch. “What’s Wrong With Factory Farms?” FWW, (n.d.). Retrieved December 6, 2016, from
  20. Graham, Jay P. et al. “The Animal-Human Interface and Infectious Disease in Industrial Food Animal Production: Rethinking Biosecurity and Biocontainment.” Public Health Report, 123(3): 282–299 (May-June 2008). Retrieved January 13, 2017, from
  21. Ibid.
  22. Chee-Sanford, JC et al. “Fate and transport of antibiotic residues and antibiotic resistance genes following land application of manure waste.” Journal of Environmental Quality, 38(3), 1086-1089 (2009). Retrieved January 13, 2017, from
  23. Hribar, Carrie. “Understanding Concentrated Animal Feeding Operations and Their Impact on Communities.” National Association of Local Boards of Health: Ohio, 2010. Retrieved January 13, 2017, from
  24. McEachran, Andrew D., et al. “Antibiotics, Bacteria, and Antibiotic Resistance Genes: Aerial Transport from Cattle Feed Yards via Particulate Matter.” Environmental Health Perspectives (April 1, 2015). Retrieved January 13, 2017, from
  25. Ahmad, Aqeel, et al. “Insects in confined swine operations carry a large antibiotic resistant and potentially virulent enterococcal community.” BioMed Central Microbiology 11:23 (2011). Retrieved January 13, 2017, from 
  26. Nadimpalli, Maya. “Persistence of livestock-associated antibiotic-resistant Staphylococcus aureus among industrial hog operation workers in North Carolina over 14 days.” Occupational & Environmental Medicine, 72(2) (September 8, 2014). Retrieved May 31, 2018, from
  27. Schulz, Jochen, et al. “Antimicrobial-Resistant Escherichia coli Survived in Dust Samples for More than 20 Years.” Frontiers in Microbiology, 7: 866 (2016). Retrieved January 13, 2017, from
  28. Graham, JP, et al. “Antibiotic resistant enterococci and staphylococci isolated from flies collected near confined poultry feeding operations.” Science of the Total Environment, 407(8):2701-10 (April 1, 2009). Retrieved January 13, 2017, from
  29. Zurek, Ludek and Ghosh, Anuradha. “Insects Represent a Link between Food Animal Farms and the Urban Environment for Antibiotic Resistance Traits.” Applied Environmental Microbiology, 80(12): 3562-3567 (June 2014). Retrieved January 13, 2017, from
  30. Centers for Disease Control and Prevention. “Antibiotic Resistance Threats in the United States.” CDC,  2013. Retrieved January 13, 2017, from
  31. Centers for Disease Control and Prevention. “Antimicrobial Resistance Posing Growing Health Threat.” CDC, 2011. Retrieved January 13, 2017, from
  32. O’Neil, Jim. “Antimicrobial Resistance: Tackling a crisis for the health and wealth of nations.” The Review on Antimicrobial Resistance, December 2014. Retrieved January 13, 2017, from
  33. Chan, Margaret. “World Health Day 2011: Combat drug resistance: no action today means no cure tomorrow.” World Health Organization, April 6, 2011. Retrieved January 13, 2017, from
  34. World Health Organization. “Antimicrobial resistance: global report on surveillance 2014.” WHO, April 2014. Retrieved January 13, 2017, from
  35. US Department of Health and Human Services. “FDA’s Strategy on Antimicrobial Resistance – Questions and Answers.” US Food & Drug Administration, 2015. Retrieved January 13, 2017, from
  36. PEW Charitable Trusts. “FDA Poliilces on Antibiotic Use in Food Animals.” PEW, May 6, 2016.  Retrieved January 13, 2017, from
  37. 116th Congress. “H.R.1552 – Preservation of Antibiotics for Medical Treatment Act of 2015.”, 2015-2016. Retrieved January 13, 2017, from
  38. Ibid.
  39. World Health Organization. “World Health Assembly addresses antimicrobial resistance, immunization gaps and malnutrition.” WHO, May 25, 2015. Retrieved January 13, 2017,
  40. Boland, Jay P. et al. “Growth Promoting Antibiotics in Food Animal Production: An Economic Analysis.” Public Health Reports, 122(1), 79-87 (Jan-Feb 2007). Retrieved January 13, 2017, from
  41. Teilant, Aude and Laxminarayan, Ramanan. “Economics of Antibiotic Use in U.S. Swine and Poultry Production.” Choices, 1st Quarter, 30(1), (2015), Agricultural & Applied Economics Association. Retrieved January 13, 2017, from
  42. Ibid.
  43. Ibid.
  44. Animal Welfare Approved. “Beef Cattle and Calves Standards.” A Greener World, (n.d.). Retrieved January 13, 2017, from
  45. USDA Agricultural Marketing Service. “Organic Livestock Requirements.” USDA, July 2013. Retrieved January 15, 2017, from
  46. US Department of Agriculture. “Meat and Poultry Labeling Terms.” USDA, January 15. Retrieved April 19, 2019, from