May 16, 2011

US FDA concerned over antibiotics used on animals

Majority of the millions of pounds of antibiotics administered to livestock in the US are mixed into the feed that animals eat, which is of concern to the US Food and Drug Administration (FDA).

The FDA reported last year that livestock grown in the US consumed about 28.6 million pounds of antibiotics. In a letter to Rep. Louise Slaughter (D., N.Y.), FDA said about 74% of those drugs was fed to the animals. A smaller amount was administered through water and even less was injected directly into the animals.

Some contend that mass dosing of antibiotics to livestock through feed speeds up antibiotic resistance in bacteria that can threaten human health.

Livestock groups, such as the National Pork Producers Council, disagree. When feed is used as a method of administering antibiotics, "some animals will eat too much, some animals will not eat enough and some will eat just the right amount," said Gail Hansen, a farming specialist with the Pew Charitable Trusts' Health Group.

There is no evidence of inconsistency in the amount of antibiotics fed to livestock, according to the National Pork Producers Council. They said, "Feed mill mixing equipment is designed to add antibiotics in the proper amounts."

The groups also said there is no evidence to prove that antibiotics used on animals will contribute to the growth of bacteria which resists drugs used to treat humans.

The amount of bacteria found in livestock, meat and humans that have become resistant to antibiotics (the drugs humans need to fight off infections) remains substantial and, in some categories, continues to grow, according to government monitoring.

The FDA has long been concerned that the widespread use of antibiotics on farms will contribute to the quickening of the pace that the drugs become useless to humans.

"Antimicrobial resistance, and the resulting failure of antimicrobial therapies in humans, is a mounting public health problem of global significance," the FDA said in a report released last year. "This phenomenon is driven by many factors including the use of antimicrobial drugs in both humans and animals."