The same antibiotics used to treat sick people are also given to healthy animals — in much greater numbers — to make them grow faster and to compensate for overcrowded and unsanitary conditions. These practices are contributing to the emergence of drug-resistant superbugs that make infections more difficult and costly to treat. In 2011, more antibiotics were sold for use in meat and poultry production than ever before.

Related: FDA Annual Report on Antimicrobials Sold or Distributed for Food-Producing Animals in 2011