The FDA last week released its annual report on antibiotic use in food animals, showing a year-over-year increase in line with expanding cattle and hog inventories.

The “2014 Summary Report on Antimicrobials Sold or Distributed for Use in Food-Producing Animals” shows domestic sales and distribution of antimicrobials approved for use in food-producing animals increased by 22 percent from 2009 through 2014, and increased by 4 percent from 2013 through 2014.

Between 2013 and 2014, U.S. cattle inventories increased by 2.4 percent, from 87.7 million to 89.8 million. During the same time, numbers of U.S. hogs and pigs increased by 7.1 percent from 61.5 million to 65.9 million, according to the USDA. Together, cattle and hog inventories grew by about 4.3 percent from 2013 through 2014. Broiler inventories during the same period remained flat, with a year-over-year increase of less than 1 percent.

This summary report presents the sales and distribution data for the 2014 calendar year, along with multiple years of domestic sales and distribution data, observations on the changes in the sales and distribution of these drugs for 2014 compared with 2009 and changes in the sales and distribution of these drugs for 2014 compared with 2013.

Key findings in the report include:

  • Domestic sales and distribution of antimicrobials approved for use in food-producing animals increased by 22 percent from 2009 through 2014, and increased by 4 percent from 2013 through 2014.
  • In 2014, domestic sales and distribution of medically important antimicrobials accounted for 62 percent of the domestic sales of all antimicrobials approved for use in food-producing animals. Tetracyclines accounted for 70 percent of these sales, penicillins for 9 percent, macrolides for 7 percent, sulfas for 5 percent, aminoglycosides for 3percent, lincosamides for 2 percent, and cephalosporins and fluoroquinolones each for less than 1 percent.
  • Domestic sales and distribution of medically important antimicrobials approved for use in food-producing animals increased by 23 percent from 2009 through 2014, and increased by 3 percent from 2013 through 2014. Tetracycline sales increased by 25 percent from 2009 through 2014 and 1 percent from 2013 through 2014.
  • Lincosamide sales volume showed the greatest percentage increase in domestic sales (150 percent) from 2009 through 2014, while sulfas sales volume showed the greatest percentage increase in domestic sales (18 percent) from 2013 through 2014.
  • The percentage of domestic sales and distribution of medically important antimicrobials approved for production use decreased from 72 percent to 68 percent from 2009 through 2012, but then remained unchanged at 72 percent from 2013 through 2014. Production applications of those products are set to decline considerably next year, when drug sponsors remove production labels from medically important antibiotics in accordance with FDA’s Guidance for Industry 213.
  • The percentage of domestic sales and distribution of medically important antimicrobials approved for use in food-producing animals that are sold over-the-counter (OTC) did not appreciably change from 2009 through 2014, going from 98 percent to 97 percent. That number likely will decline significantly in 2017, when FDA rules will end OTC sales of medically important antibiotics used in feeds and classify those products as veterinary feed directive (VFD) drugs.

The report’s authors caution against comparing the data for sale of antibiotics for use in food animals with data from other sources on sales of antibiotics for human medicine. Those comparisons can be misleading for several reasons.

  • The number of humans in the population compared to the much larger number of animals in each of the many animal species.
  • The differences in physical characteristics of humans, such as weight and physiology, compared to various animal species.
  • Duration and dosage of antibacterial drug administration may also vary by indication and, in general, between the various animal species and humans due to differences in physiology.
  • Available animal sales and distribution data are not reported to the FDA by each use indication and, thus, do not allow the FDA to distinguish between or among the different types of uses. The data, therefore, do not allow a direct comparison of the amounts of antimicrobials sold for certain human uses with those sold for certain animal uses.
  • Veterinarians commonly utilize human antimicrobial drugs in their companion animal patients; therefore, amounts presented for certain human antimicrobial drugs may represent some unknown portion sold for use in companion animals.

Read the full summary report from FDA.