U.S. regulators are taking steps to check the spread of antibiotic-resistant infections from animals to humans. The Food and Drug Administration, or FDA, is giving farmers three years to end their practice of using antibiotics solely to help animals grow. The European Union already has banned this use of antibiotics, but it is common in the developing world.

The Food and Drug Administration has issued guidelines for phasing out the use of antibiotics for purposes other than treating, controlling or preventing disease.

Today, the use of small doses of antibiotics to promote animal growth is a common practice in large-scale livestock operations around the world. But new strains of infectious bacteria resistant to these drugs are on the rise.

Antibiotic misuse in people is one factor, says FDA Deputy Commissioner Michael Taylor.