Mayo Clinic Health Library

Antibiotic resistance: Understanding the connection to antibiotic use in animals raised for food

Updated: 03-07-2018

Antibiotics are powerful medications designed to kill bacteria or stop its growth. However, there are times when antibiotics can actually be harmful. For both humans and animals, misusing and overusing antibiotics can lead to the development and spread of antibiotic-resistant bacteria, which in turn may lead to antibiotic-resistant infections.

All animals have bacteria in their intestines. Antibiotics that are given to food-producing animals treat infection and kill some bacteria, but resistant bacteria will often survive and multiply.

Antibiotic-resistant bacteria can then spread to:

  • Other animals that are raised in the same environment
  • Animal products that people eat, such as chicken and steak
  • Produce, through contaminated water or soil
  • The environment, through animal feces
  • Prepared food, through contaminated surfaces, such as a cutting board used to cut chicken then chop vegetables without being washed between uses

People can become sick with antibiotic-resistant infections when they eat food that's been contaminated with antibiotic-resistant bacteria and not properly prepared, or from handling contaminated animals or surfaces and not practicing proper hand-washing or environmental cleaning afterward.

Antibiotic-resistant infections can lead to mild illnesses, or in some cases, severe illnesses that may lead to death.

The Food and Drug Administration (FDA) regulates antibiotics that are used in humans and animals. In animals raised for food, FDA-approved uses of antibiotics include:

  • Treating sick animals
  • Controlling illness in a group of animals when some of the animals are sick
  • Preventing illness in a group of animals at risk of becoming sick
  • Promoting growth and weight gain

The FDA and Centers for Disease Control and Prevention recommend antibiotics that are important for human health be used in food-producing animals only when it's necessary to ensure the health of the animal, not to promote growth. A doctor who treats animals (veterinarian) should oversee or advise these conditions.