Antibiotic Overuse in Animals?>
Be Well

Antibiotic Overuse in Animals

by David Tuller, DrPH

For more than a decade, journalist Maryn McKenna has tracked the threats posed by the growing number of virulent and antibiotic-resistant bacterial species. Her last book, Superbug: The Fatal Menace of MRSA, was a gripping and highly praised account of the how an epidemic of deadly staph infections emerged from pathogens previously controlled by antibiotics. McKenna (a long-time colleague and friend) currently blogs about infectious diseases and antibiotic resistance at and is on the board of the Association of Health Care Journalists.

A recent piece by McKenna, “Imagining the Post-Antibiotics Future,” makes for scary and eye-opening reading. (McKenna produced the piece in collaboration with the Food & Reporting Network, a non-profit news organization supporting investigative reporting on food, agricultural and environmental health.

Many consumers believe, mistakenly, that the antibiotics crisis is largely due to doctors overprescribing them and patients misusing them. Both of those factors play a role, of course, but McKenna points out the real crux of the problem: Eighty percent of all antibiotics in the U.S. are prescribed for farm animals.

Moreover, most of those drugs are not given to treat sick animals but to prevent disease and bulk animals up more quickly; for reasons not yet fully understood, antibiotics are known to promote growth when given to healthy livestock.

Just last week, the Food and Drug Administration (FDA) announced a major plan to restrict the use of antibiotics in livestock production. While that represents a first step in addressing the problem, serious questions remain about the effectiveness of the agency's proposed measures, as Scientific American quickly noted.

In any event, McKenna provides a stark reminder of the stakes in this battle against drug-resistance. In her "post-antibiotic" article, she explains how the rampant use of antibiotics in livestock production triggers the chain of events that allows antibiotic-resistant bacteria to thrive—in the animals’ guts, in the manure that gets spread onto other fields, and from there into water sources and the larger environment. In a 2011 survey of retail meat, the FDA reported that almost two-thirds of chicken breasts and 44 percent of ground beef carried bacteria resistant to the common antibiotic tetracycline.

But McKenna takes it a step beyond and describes one likely outcome of our rampant overuse of antibiotics: a future more closely resembling the pre-penicillin age than our own. Her powerful piece reminds us how much we all take for granted the protections we are at serious risk of losing; protections, in fact, that growing numbers of people have already lost.

“Before antibiotics,” she writes, “five women died out of every 1,000 who gave birth. One out of nine people who got a skin infection died, even from something as simple as a scrape or an insect bite. Three out of 10 people who contracted pneumonia died from it. Ear infections caused deafness; sore throats were followed by heart failure. In a post-antibiotic era, would you mess around with power tools? Let your kid climb a tree? Have another child?”

In short, getting a handle on the antibiotics crisis—and it truly is a crisis, as the Centers for Disease and Prevention (CDC) and other medical experts have warned repeatedly—demands much more than doctors and patients learning to use antibiotics responsibly. While those steps are necessary and important, even people who pursue such strategies are exposed, without consent, to antibiotics and antibiotic-resistant bacteria in our meat, our water and our produce.

Beyond personal change, a critical need is for the U.S. to follow in the footsteps of more environmentally oriented European countries—those that have already taken much stricter steps to prevent massive dosing of healthy livestock with antibiotics. For the FDA's recent action to have any real meaning, the agency must follow up with rigid deadlines for compliance and strong enforcement and sanctioning mechanisms. Otherwise, we face a real risk of confronting the post-antibiotic future portrayed by McKenna.