Except for a few early hiccups regarding the methods used in weaning piglets, production levels of livestock and poultry have either stayed the same or increased. So how did Danish producers make this transition, and why isn’t the U.S. jumping to follow suit? Like many things in industrial agriculture, the answer is not clear.

If any country knows how to intensively produce food animals, particularly pigs, it is Denmark. In 2008, farmers produced about 27 million hogs. In fact, the Scandinavian country claims to be the world’s largest exporter of pork.  Thus Scientific American editors argue that the Danish pork production system should serve as a suitable model to compare to ours. U.S. agriculture economists from Iowa State University agree. In a 2003 report, Drs. Helen Jensen and Dermot Hayes stated that Denmark’s pork industry is “…at least as sophisticated as that of the United States… and is therefore a suitable market for evaluating a ban on antibiotic growth promotants (AGPs).”

Based on Denmark’s experience, concerns that an AGP ban in the U.S. would cripple the industry appear to be overblown. A study published last year in the American Journal of Veterinary Medicine by Danish researchers suggested that Denmark’s AGP ban in food animals reduced overall antibiotic use and did not significantly impact production. In fact, recent numbers from Denmark show production levels of hogs increased by roughly 50% between 1992 and 2008.

So what additional changes did Danish hog producers make in their methods of production to ensure that the AGP ban did not negatively affect their bottom line to a significant degree? Robert Martin, Senior Officer of the Pew Environment Group and former Executive Director of the Pew Commission on Industrial Farm Animal Production, visited several Danish hog farms in 2009 to see first hand what producers were doing to compensate for not being able to use antibiotics as growth promoters. Martin listed some of what he describes as the most important changes:

•Switching to lower density models of housing pigs

•The use of open pen & deep bedding systems

•Cleaning barns more frequently and systematically

•Improved ventilation systems

•Improved quality of feed

•Extending weaning period for piglets

Martin explains that many of these changes were phased in as farmers adopted a set of new best practices. Martin says immediately following the ban, Danish producers did see an increase in mortality of young pigs. “But instead of reverting to using antibiotics as a crutch,” Martin continued, “they initiated changes in their system.” For example, Martin learned that many producers extended the piglet weaning times by about 10 days, allowing maternal antibodies in milk to provide increased immunity. Martin also pointed out that reducing the crowded conditions and switching to a dry, deep bedding system, “allowed them to manage waste more effectively.” He said the changes are also “more humane for the pigs.” Moreover, Martin says, “They also paid more attention to feed mixtures instead of relying on antibiotics for weight gain.”

Dr. Jensen and Hayes’s report, published in the Iowa Ag Review, determined a ban similar to Denmark’s could cost the U.S. industry more than $700 million dollars over 10 years and increase the price of pork by about 2 percent at the grocery store. Hayes noted, in recent email exchanges with the Center for a Livable Future, that in the long run a ban would not keep producers from making money. He also wrote, “hog farmers would reduce production until prices recovered, so there is no profit impact.” When it comes to the study’s findings Hayes believes the economics are secondary:

“The key take away for me from our studies was that the ban at the finishing stage worked as planned and reduced antibiotic use by a lot. However, when they extended the ban to the weaning state they ended up using more antibiotics and these were stronger human-use antibiotics. So a ban at the weaning stage did not work in terms of its original intent.”

It is worth noting that recent Denmark data shows weaner mortality is significantly lower since the ISU study was published in 2003. Despite that fact, Hayes is correct. The therapeutic use of antibiotics has increased since the ban was instituted. According to the latest Danish Integrated Antimicrobial Resistance Monitoring and Research Program (DANMAP) report, therapeutic antibiotic use rose by almost 13% from 2008 to 2009. DANMAP also found the occurrence of resistance in Danish pork increased during that time period, “and is not significantly lower than in imported pork.” However, resistance to the antibiotic ciprofloxacin, an important antibiotic in human medicine, was very low in E. coli from Danish pork in contrast to imported pork.  It is important to point out that therapeutic use poses much less antibiotic resistance risk than low-dose application.  Don’t forget, Denmark’s overall antibiotic use in all food animal production remains nearly 40% lower then when the ban was first initiated.

If the AGP ban is, at the very least, reducing overall antibiotic use and Danish pork production levels are increasing why wouldn’t U.S. producers follow suit? The National Pork Producers Council (NPPC) lobbyists publicly maintain they still don’t believe antibiotic use in food animals poses a risk to human health. In a presentation prepared for the World Pork Expo 2010, Chelsea Redalen, the NPPC’s Director of Government Relations, maintained that there is “little to no evidence that restricting or eliminating the use of antimicrobials in food-producing animals would improve human health or reduce the risk of antimicrobial resistance to humans.”

Statements like these, repeatedly made by hog industry representatives, leave many public health experts exasperated.  Numerous peer reviewed research studies including in the U.S. and the Netherlands clearly demonstrate the transmission of antibiotic resistant bacteria from food animals to people. Studies out of the Netherlands published in the Journal of Emerging Infectious Diseases and the Annals of Clinical Microbiology and Antimicrobials, demonstrate that MRSA (Methicillin-resistant Staphylococcus aureus) was transmitted from pigs to a farmer, and between pig farmers and their family.

Despite industry claims, U.S. government health officials have concluded there are direct links between antibiotic use in food animal production and the risk of antibiotic resistant infections in people. Responding to a letter from Drs. Robert Lawrence and Keeve Nachman of the Johns Hopkins Center for a Livable Future (CLF), the director of the U.S. Centers for Disease Control and Prevention, Dr. Thomas Frieden, confirmed that the CDC, “feels there is strong scientific evidence of a link between antibiotic use in food animals and antibiotic resistance in humans.”

CLF helped bring to light recently released FDA data showing that 80% of the antibiotics produced for human and animal use in the U.S. are sold for use in food animals. Even if significant portions of those antibiotics are used to treat disease, Dr. David Love, CLF scientist, says he finds that statistic, “astounding.” Love believes, “if producers are reliant on the use of antibiotics to produce animals in a highly concentrated way, it means that the design of these farms makes them breeding grounds for diseases.” “Even more troubling to me,” Love says, “is the unwise use of antibiotics for growth promotion in animal production, which compromises antibiotics, a precious resource used to protect the public’s health.”

Currently there is proposed federal legislation that would greatly limit antibiotic use in U.S. food animal production. Congresswoman Louise Slaughter (D-NY) recently reintroduced the Preservation of Antibiotics for Medical Treatment Act, better known as PAMTA. The bill would ban the routine use of antibiotics “deemed” critical in human medicine to promote growth in healthy animals.

So, should the U.S. follow Denmark’s lead and stop all food animal producers from dishing out low dose-antibiotics? Public health experts say it appears that those with a higher priority on limiting health risks are at loggerheads with those unwilling to change or corporations more concerned about the risks of increased costs.  One thing is clear – most large pork producers do not plan on instituting a ban voluntarily.

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Ralph Loglisci’s “Will the U.S. hog industry ever kick its reliance on low-dose antibiotics?” first appeared in Grist on April 5, 2011 and on Loglisci’s Livable Future Blog on April 6, 2011. Republished with permission.

However, people use a much smaller portion of antibiotics sold in this country compared to the amount set aside for food animals.  In fact, according to new data just released by the Food and Drug Administration (FDA), of the antibiotics sold in 2009 for both people and food animals almost 80 percent were reserved for livestock and poultry.

A huge portion of those antibiotics were never intended to fight bacterial infections, rather producers most likely administered them in continuous low-dosages through feed or water to increase the speed at which their animals grew.  And that has many public health experts and scientists troubled.

For years scientists concerned about the threat of antibiotic resistant bacteria in food animal production have been trying to figure out just how much antibiotics producers are using each year.  The best they could do was come up with rough estimates.  That is because the data was never publicly available, until now.

In accordance with a 2008 amendment to the Animal Drug User Fee Act, for the first time the FDA released this month an annual amount of antimicrobial drugs sold and distributed for use in food animals.  The grand total for 2009 is 13.1 million kilograms or 28.8 million pounds.  I found the stories covering this revelation interesting, but they did not convey the whole picture.  It is important to understand how this amount compares to the total available for people.  So, I decided to find out for myself and contacted the FDA for an estimate of the volume of antibiotics sold for human use in 2009.  This is what a spokesperson told me:

“Our Office of Surveillance and Epidemiology just finished an analysis based on IMS Health data.  Sales data in kilograms sold for selected antibacterial drugs were obtained as a surrogate of human antibacterial drug use in the U.S. market.  Approximately 3.3 million kilograms of antibacterial drugs were sold in year 2009.  OSE states that all data in this analysis have been cleared for public use by IMS Health, IMS National Sales Perspectives™.”

3.3 million kilograms is a little over 7 million pounds.  As far as I can determine, this is the first time the FDA has made data on estimates of human usage public.  Below is a breakdown of the FDA numbers prepared by my colleague, Dr. David Love, also from the Johns Hopkins Center for a Livable Future, which compares the estimated amounts of human usage with food animal usage.

Take a look at the data for tetracycline.  More than 10 million pounds of the antibiotic were sold for the use in food animals.  That’s more than all of the antibiotics combined set aside for humans in 2009.  Many studies suggest the high use of tetracycline in food animals, particularly in pigs, has lead to the increased rates of bacterial resistance to the antibiotic, such as Methicillin-resistant Staphylococcus aureus or MRSA.

Despite this new information, the hog industry denies the suggestion that it is overusing antibiotics.  In response to the FDA’s report, the National Pork Producers Council also pointed out to Food Safety News‘ Helena Bottemiller that, “ionophores … are not used in human medicine, they don’t have anything to do with the effectiveness of antibiotics in people.”  That statement is inaccurate.  All uses of antibiotics have the potential to decrease the effectiveness of antibiotics in people.  Ionophores are no exception.  While several industry funded studies determined that ionophore use in animals is “not likely” to transfer resistance from animals to people, researchers couldn’t come to a definitive conclusion because ionophores can lead to bacterial resistance to the antibiotic bacitracin, which is commonly used to treat skin and eye infections.

Every time an antibiotic is used there is a risk of adding to the growing pool of antibiotic resistance.  LivableFutureBlog readers might recall an October blog post in which Dr. Ellen Silbergeld, professor of environmental health sciences at the Johns Hopkins Bloomberg School of Public Health, warned that, “Bacteria respond to chemical structures, not brand names, and resistance to one member of a pharmaceutical class results in cross resistance to all other members of the same class.”  Silbergeld says when bacteria develop resistance to one member of that class of antibiotics it can be resistant to all.

So, what is the government doing to ensure we don’t squander the effectiveness of antibiotics for human use on the production of food animals?  Since President Barack Obama took office, the FDA says it has taken several steps.  Dr. Joshua Sharfstein, Principal Deputy Commissioner of the FDA, took a stand last year by stating that the Administration, “supports ending the use of antibiotics for growth and feed efficiency” in food animals.  However, instead of requiring industry take action, the FDA released a draft-guidance last June that essentially asks industry to voluntarily end the use of antibiotics as growth promoters in food animals and include veterinary oversight or consultation on all antibiotic use.

Lawmakers such as Congresswoman Louise Slaughter and Senator Barbara Boxer have been introducing versions of the Preservation of Antibiotics for Medical Treatment Act (PAMTA) for more than a decade that would mandate antibiotic use changes in food animals.  Earlier this year it looked like the bill had a good chance of passing, but the bill failed to make it to the floor of the House or Senate.  While not perfect, PAMTA would ban the use of medically important antibiotics as growth promoters.  Passage of PAMTA would be an important step in saving the potency of antibiotics for human use.  However, the current version of the bill could be stronger if it followed more closely the recommendations from the Pew Commission on Industrial Farm Animal Production final report, which call for a ban on the non-therapeutic use of all antibiotics, not just those considered medically important, in food animals.

Now that we officially know that food animals use an overwhelming majority of our antibiotics, I hope it is more clear to everyone that legislation limiting the overuse and misuse of antibiotics in livestock and poultry must be passed.  The next battle, which industry has already begun, is defining what non-therapeutic use will constitute.  Producers are already claiming that the use of antibiotics for growth promotion has decreased, maintaining current low-dose usage is aimed at disease prevention.  Regardless, all low-dose usage of antibiotics can lead to a significant increase in antibiotic resistance.  As Dr. Alexander Fleming, the discoverer of penicillin warned, “It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them, and the same thing has occasionally happened in the body.”

If you don’t believe me just ask Rear Admiral Ali Kahn, Assistant Surgeon General and Acting Deputy Director for the Center for Disease Control and Prevention’s National Center for Emerging and Zoonotic Infectious Disease.

Just this summer, during a hearing before the House Energy and Commerce Committee, Dr. Kahn testified that, “there is unequivocal evidence and relationship between [the] use of antibiotics in animals and [the] transmission of antibiotic-resistant bacteria causing adverse effects in humans.”

Knowing this, I continue to be frustrated with the fact that Agriculture Secretary Tom Vilsack does not publically recognize that the industrial food animal production system is a leading contributor to the increase of antibiotic resistance in pathogens that infect people and animals.

Earlier this month at a National Cattlemen’s Beef Association meeting, Vilsack reportedly responded to a question about the Preservation of Antibiotics for Medical Treatment Act (PAMTA) by saying the, “USDA’s public position is, and always has been, that antibiotics need to be used judiciously, and we believe they already are.”

That quote had me scratching my head when I read it in a New York Times Op-Ed a couple of weeks ago.  The Times’ editors interpreted the statement as saying Vilsack believes there is no need to change antibiotic use policy among food animal producers.  That contradicts the positions of both the FDA and CDC.  The Times pointed out that while neither regulatory agency is doing enough to address the problem both, at least, recognize that current antibiotic use should change.

U.S. Rep. Louise Slaughter (D-NY) and Sen. Dianne Feinstein (D-CA), the primary sponsors of PAMTA, which calls for limits on the non-therapeutic use of certain antibiotics in livestock production, were perplexed with Secretary Vilsack’s comment, too.

They recently requested that Vilsack clarify his stance on the issue.  In a letter, Slaughter and Feinstein wrote, “Media reports suggest that you may have mischaracterized our legislation and made statements that run contrary to previous positions taken by Department officials. We hope that you can provide us with reassurance that your off-the-cuff remarks were taken out of context, and that you remain committed to protecting human and animal health.”

I called the Secretary’s office for a clarification myself.  A USDA spokesperson sent me the following statement:

“USDA believes that antibiotic use should be used judiciously to slow the development of resistance in animals. USDA believes livestock producers are good stewards, use antibiotics judiciously, but there are some bad actors, and continued use can develop resistance.   USDA wants to be a partner with Congress, producers and other federal partners to address this important issue.”

This statement does little to address the issue at hand.

The problem does not lie with a few rogue producers. Rather, there is an industry standard of feeding livestock and poultry low concentrations of antibiotics and other antimicrobials, like arsenicals, in their feed to promote growth. (All of which is approved by the FDA, by the way.) Considering industry produces more than 10 billion food animals a year (the majority chicken and hogs) the amount of antibiotics used in food animals is astronomical.

Case in point, researchers at Johns Hopkins Bloomberg School of Public Health estimate that the amount of antibiotics North Carolina hog producers use in their swine feed every year exceeds the total amount of antibiotics used to treat infections in people nationwide.  It is estimated that as much as 70 percent of the antimicrobial drugs used in the US are administered to animals not to treat disease, but to purportedly promote growth or prevent the spread of pathogens among livestock and poultry living in intensive confinement.

All uses of antibiotics contribute to drug resistance.  While human medicine plays a large role in the antibiotic drug resistance problem, new research is clearly showing that resistant bugs from food animals are starting to show up in people more and more.

Johns Hopkins Bloomberg School of Public Health and Hershey Medical Center researchers recently published a study that confirms other research indicating that hospitals are no longer the main source of exposure for methicillin resistant Staphylococcus aureus or MRSA.  And researchers in Europe have published evidence that livestock production is increasingly becoming a major source for the Super Staph bug.

The reason why PAMTA is focusing on the non-therapeutic use of antibiotics in animals is that it is contrary to everything we have known for 70 years about preserving these drugs.  The amounts of antibiotics used in animal feeds are low and are not intended to kill bacteria.  That creates a problem first recognized by the inventor of penicillin, Alexander Fleming, who warned in 1945 that, “the greatest possibility of evil in self-medication is the use of too small doses so that instead of clearing up infection, the microbes are educated to resist penicillin.”

Many infectious disease experts believe that we may very well be close to a post-antibiotic era, which could mean a return to a time when a simple bacterial infection could cause your child, your parents or you serious health problems or even death.

In their letter to Vilsack, Feinstein and Slaughter tried to clear up what they call common misperceptions about their legislation:

“The Preservation of Antibiotics for Medical Treatment Act does not ban the use of antibiotics.  And in fact we share your belief banning all uses of antibiotics would be counterproductive.  Instead, the Preservation of Antibiotics for Medical Treatment Act addresses usage of seven antibiotics that are critical in human medicine, phasing them out for non-therapeutic uses in livestock production.”

I respectfully suggest that the common misconception about PAMTA Feinstein and Slaughter should focus on is the misguided belief by many people that their bill would ban the use of antibiotics to treat sick food animals.  The legislation allows veterinarians to authorize proper use of antibiotics to treat or prevent disease.  .

While I support the proposed legislation to limit antibiotic use in food animals, I have continually made it clear that the current language in PAMTA should be stronger. I believe the concession to focus only on the so-called “seven antibiotics that are critical in human medicine” weakens the bill.  If we are going to be up front with the public, we must make it clear that bacteria don’t differentiate between types of antibiotics, whether they are approved for human medicine or not.

Dr. Ellen Silbergeld, professor of environmental health sciences at the Johns Hopkins Bloomberg School of Public Health, recently testified before Pennsylvania’s state Legislature regarding its own proposed legislation to limit antibiotic use in food animals.  She warned that, “bacteria respond to chemical structures,
not brand names, and resistance to one member of a pharmaceutical class results in cross resistance to all other members of the same class.”

For example, she noted that resistance in Campylobacter (a nasty bug that the USDA says is the second most frequently reported cause for foodborne illness) to the antibiotic enrofloxacin (an antibiotic approved for pets and other domestic animals, commonly called Baytril) results in resistance to the very important human therapeutic antibiotic ciprofloxacin.  Both antibiotics are two of more than 30 variations of the fluroquinolone class of antibiotics. As Silbergeld explains, when bacteria develop resistance to one member of that class of antibiotics, they can be resistant to all.

Authors made certain that language in PAMTA would ensure that any “derivative of a drug that is used in humans or intended for use in humans to treat or prevent disease or infection caused by microorganisms” would be banned from being used as a growth promoter in food animals. But–and this is a big “but”–the bill does not address the fact that the use of any antibiotic can lead to a pool of resistance that can affect every antibiotic class–important to both human and animal medicine.

Silbergeld has long warned that antibiotic resistant bacteria can share the genes (bits of DNA) that code for resistance with other bacteria in the environment and therefore readily transfer antibiotic resistance.  Sharing genes between bacteria is almost as easy for these organisms as forwarding an email to a friend; only bacteria are exchanging genetic code information.  Resistance genes for multiple classes of antibiotics can be shared in the same “email,” or what scientists call plasmid “cassettes.”

For instance, some isolates of Salmonella and Campylobacter have been found to have taken up a “cassette” of resistance genes that protect them from as many as 17 different antibiotic drugs.

What this means is that not only can bacteria share resistance genes within the same class of antibiotics such as the fluoroquinolines class antibiotics containing enrofloxacin (restricted for veterinary use) and ciprofloxacin (critical to human medicine), but also bacteria have the capability of exchanging resistance genes between different classes of antibiotics like we’ve seen in Salmonella and Campylobacter.

Allowing the non-therapeutic use of any antibiotic in food animals, regardless of whether it is defined as important to human medicine or not, could still lead to the development of bacteria that are resistant to an antibiotic that you and I may one day depend on.

The concept behind PAMTA is an important one.  We must stop wasting one of medicine’s most important lifesaving discoveries simply as a way to increase the growth of food animals and subsequently profit for the food industry.  If PAMTA is not passed this year I hope that the next version would follow more closely the recommendations from the Pew Commission on Industrial Farm Animal Production’s final report, which calls for “the phasing out and then banning the non-therapeutic use of [ALL] antimicrobials in food animal production.”

Last Monday, the FDA fired a serious warning shot across the bow of industrial food animal producers stating in a new draft guidance that it expects industry to change its antibiotic use practices. The draft guidance asks for two simple things: stop using “medically important” antibiotics as growth promoters, limiting use to only treating sick animals; and ensure that producers do not administer these drugs without veterinary supervision. Unfortunately, the FDA says guidance documents, “do not establish legally enforceable responsibilities.”

Why didn’t leadership go a step further and issue a proposed rule? I’ll address the possible answer in a moment. But what has me scratching my head are discussions about potentially changing a current medicated animal feed rule that’s already on the books.

The FDA recently sent out a notice warning that it might modify its veterinary feed directive (VFD), citing informal complaints that the rule is “overly burdensome.” The VFD was issued 10 years ago in response to the passage of the Animal Drug Availability Act of 1996, which required the FDA to regulate the approval and marketing of new animal drugs and medicated feeds. Any medicated feed that falls under the VFD category can only be used under the supervision of a veterinarian. According to the American Veterinary Medical Association’s Website, “the purpose of the added professional control is to reduce the rate of development of [antimicrobial] resistance and thereby prolong the period of effectiveness of the medication.” It is important to note that the VFD only applies to new drugs and that feeds containing approved antibiotics before 2000 can and are sold over-the-counter without a prescription or supervision of a veterinarian.

So, if the FDA Principal Deputy Commissioner Joshua Sharfstein went out on a limb to call the overuse of antibiotics in food animals, “an urgent public health issue,” why would FDA consider changing a 10-year-old rule that could relax regulation of antibiotic use even further? That’s exactly what the American Academy of Pediatrics, The Pew Charitable Trusts, Union of Concerned Scientists, Institute for Agriculture and Trade, Food and Animal Concerns Trust, and Humane Society of the United States want to know.  Back in May the organizations sent a list of specific questions to FDA Commissioner Margaret Hamburg regarding the Advance Notice of Proposed Rulemaking (ANPR):

– From whom did the [overly burdensome] comments come–the industrial farming industry, veterinarians, or other stakeholders?

– The FDA suggests that the ANPR is being undertaken to help “improve the program’s efficiency.” Since the primary requirement of the program is that veterinarians provide oversight on the use of certain drugs, does improved program efficiency simply mean less meaningful oversight from licensed veterinarians?

– How is the ANPR consistent with Deputy Commissioner Joshua Sharfstein’s July 13, 2009, testimony that, “protecting public health requires the judicious use in animal agriculture of those antimicrobials of importance in human medicine…FDA also believes that use of medications for prevention and control should be under the supervision of a veterinarian?” (emphasis added)

Late last month the FDA decided to extend the comment period on the ANPR for an additional 60 days, after receiving complaints that the original 90-day comment period was not enough time to develop “meaningful or thoughtful response.”  That means the public now has until August 27 to speak up.  If you’re interested in writing a response you may first want to read a new study published in PLoS One which links antibiotic use on veal calf farms in the Netherlands to a new strain of methicillin-resistant Staphylococcus aureus – ST398 (a.k.a. Staph superbug.) The authors say this is the first study that shows “direct association between animal and human carriage of ST398,” and that this latest revelation warrants the prudent use of antibiotics on the farm.

While I don’t want to see the VFD weakened in any way, I am more concerned about the medicated feeds that are not covered under the directive. Which is pretty much everything except the two drugs that have been placed under the VFD category. The Union of Concerned Scientists (UCS) estimated in 2001 that as much as 70 percent of all the antibiotics sold in the U.S. were used to promote growth in food animals. And yes, there are plenty of cases of irresponsible antibiotic use going on in people, but it doesn’t compare to the amount in animals. The UCS claims “nearly 13 million pounds [of antibiotics] per year – are used in animal agriculture for these non-therapeutic purposes. This amount is estimated to be more than four times the amount of drugs used to treat human illness.”

Of course industry disputes this claim. The Animal Health Institute–an organization that lobbies for pharmaceutical companies such as Bayer, Pfizer and Novartis–told the New York Times that it estimated only “13 percent of agricultural antibiotics were used to promote growth.” As Times reporter Gardiner Harris keenly pointed out, if the FDA, “some day bans growth promotion as a use, there is a chance producers would simply relabel such uses as preventative.”

While serving as the communications director for the Pew Commission on Industrial Farm Animal Production my colleagues and I met with AHI staff in 2006 to discuss antibiotic use in food animals. They were trying to “redefine” therapeutic and non-therapeutic uses of antibiotics even back then.  They presented us with similar statistics. It wasn’t until we started discussing the use of antibiotics to prevent production diseases, such as liver abscesses in feedlot cattle (ruminants, design
ed to eat forage such as grass or hay, that are finished on grain can develop several metabolic and infectious diseases), that we began to realize they were lumping the use of antibiotics to make up for poor living conditions and animal husbandry in the same therapeutic category. There are some hard-liners who would argue medicating animals to prevent “production diseases” should not fall under the “therapeutic” category as well.  Keep in mind, regardless of the definition, these low-dose treatments can still lead to the emergence of antibiotic-resistant bacteria. And FYI, studies reveal cattle switched from grain-based diets to hay were less likely to shed the deadly antibiotic resistant bacteria E. coli O157:H7.

So, why hasn’t the FDA called for an outright ban? Industry has thwarted the agency’s attempts to end the non-therapeutic use of antibiotics for more than three decades. If history were any indicator, a call for a new ban would most likely end with the same fate. I am certain that if FDA leadership decided to release a draft directive last week, rather than a draft guidance, industry would already be preparing to take the FDA to court. At best, a court action could tie up any rule for years; at worst, it could set back future regulations by another decade or more. That’s why public health will remain at risk until Congress takes action and passes legislation designed to end the practice once and for all.

While it is not perfect, there is proposed legislation on the table right now entitled the Preservation of Antibiotics for Medical Treatment Act (PAMTA). Congresswoman Louise Slaughter introduced the latest version of PAMTA last March. The bill calls for:

– Phase out the non-therapeutic use in livestock of medically important antibiotics;

– Require this same tough standard of new applications for approval of animal antibiotics;

– Does not restrict use of antibiotics to treat sick animals or to treat pets and other animals not used for food.

More than 300 organizations including the Johns Hopkins Center for a Livable Future, American Public Health Association, American Medical Association, and National Association of County and City Health Officials support the passage of the PAMTA.

The American Veterinary Medical Association (AVMA) is vehemently opposed to PAMTA. Dr. Michael Blackwell, public health veterinarian and vice chair of the Pew Commission on Industrial Farm Animal Production, says that to his knowledge, “the AVMA remains the only major medical or public health organization not recommending changes in agriculture practices to help ensure sustainability where the use of antimicrobials is concerned.”

Dr. Raymond Tarpley, AVMA member and retired Texas A&M professor, recently submitted a post for the Livable Future Blog imploring the AVMA to change its stance on antimicrobial use in food animals. The AVMA and industrial food animal producers claim that the benefits of low-dose antibiotic use to efficient production and food safety outweigh the risk of developing more antibiotic resistance. Dr. Tarpley says that view, however, is only valid in the context of the current unhealthy industrial animal production environment:

“… where disease risks can be heightened and growth rate performance reduced by stressors such as poor ventilation and hygiene, inadequate temperature regulation and animal crowding interfering with natural behaviors. Elevated risks have led to a dependence on low-dose antimicrobials to compensate for these suboptimal husbandry practices made worse by large numbers of animals producing large quantities of untreated wastes that often trigger respiratory distress in a microbially rich environment.”

When it comes to the FDA’s draft guidance on antibiotic use in food animals, the fact that FDA leadership is willing to take a hard-line stance on such a politically charged issue is commendable. I understand the argument that change takes time and that the agency must be methodical in its approach, especially when the powerful food animal and pharmaceutical industries will do everything they can to thwart it. However, timing is everything. If the FDA believes it cannot take a stronger stance now, then Congress must move on PAMTA. As Congress faces another potential shift in control, if PAMTA fails passage this year, I fear it could be another decade before we see an end to the irresponsible use of antibiotics in animal agriculture, and by then it might be too little too late.

Editor’s Note:  “Antibiotic Resistance in Food Animals: FDA Takes Strong Stance, But Public Health May Remain At Risk Until Congress Acts” first appeared on the Center for a Livable Future Website on July 6, 2010.  Republished with permission from the author.