Thursday, May 24, 2012

Antimicrobial oversight in veterinary news

Antibiotic resistance is growing, and we’ve all heard that doctors should prescribe fewer antibiotics. But the bulk of antibiotic use in the United States is in food animals. Producers feed antibiotics not only to sick animals, but to promote growth. This is a potential issue for human health, but the solution isn’t immediately clear. Which antibiotics specifically should be limited? Where exactly should we draw the line between use to prevent disease and use to promote growth?

A news article in the June 1 issue of the Journal of the American Veterinary Medical Association (JAVMA), “Proposal calls for changes in antimicrobial use,” (not open access) describes guidance documents published by the Food and Drug Administration about the use of antibiotics in food animals. The FDA’s plan for managing antibiotic use in livestock involves:
  • voluntary compliance by producers and pharmaceutical companies
  • cessation of use of antibiotics for growth
  • “judicious” use of antibiotics for prevention and treatment of disease
  • involvement of veterinarians in the decisions to use or not use antibtiotics in particular cases
Voluntary compliance, of course, means that new regulation is not currently intended. Producers and pharmaceutical companies could choose to ignore these guidelines. The guidelines recommend that antibiotics no longer be fed for any reason except “for uses necessary for animal health.” The JAVMA article gives specific examples of some borderline cases. For example, antibiotics might be appropriate prophylactically in the case of stressed cattle which are therefore more susceptible to particular diseases. Additionally, the guidelines suggest that pharmaceutical companies should refrain from selling certain antibiotics directly to producers, requiring that a veterinarian provide a prescription first.

What’s good here is veterinary involvement, though I’m biased in that area. Veterinarians are the group who best understand the implications of the use of particular antibiotics, both from the perspective of benefits to human health when antibiotic use is reduced, as well as benefits to animal health and producer finances when it is increased. Veterinarians will be able to make decisions more flexibly about how and when to use antimicrobials in the absence of regulations. As our understanding of appropriate use changes, changes in practice will not be delayed by the syrup-slow process of changing regulations.

What’s disappointing, but not surprising, is the failure of the JAVMA article to discuss a reduction in the need for antibiotic use in food animals to reduce disease. Conventional food animal husbandry, in my opinion, can be highly stressful for animals, with crowded housing and long-distance transportation. Antibiotics are useful to keep these highly stressed animals from succumbing to disease, but shouldn’t we also be talking about reducing their stress to reduce their susceptibility in the first place?

What’s worrisome about the proposed guidelines, of course, is obvious: will producers and pharmaceutical companies voluntarily comply? The FDA proposes a three year window to see if they do. After that, it seems likely that they will pursue a regulatory solution. I very much hope that the voluntary solution works. As I said above, I believe it’s a more agile solution, able to adapt more flexibly to changes in our understanding of antibiotic use in food animals. However, I hope the FDA is not overly optimistic about human nature by making the guidelines entirely voluntary.

June 1, 2012, Vol. 240, No. 11, Pages 1266-1277
doi: 10.2460/javma.240.11.1266


  1. "Veterinarians are the group who best understand the implications of the use of particular antibiotics"

    Sorry, but I think you're wrong there. The group who best understand the implications of using antibiotics are evolutionary biologists.

    Antibiotics are our only defense against a whole bunch of lethal, highly contagious diseases with pandemic potential. Every time you use them, you gamble. If you lose that gamble, you take one step toward evolving a strain that could kill you, your family, and a good percentage of humanity.

    Worse, if some of those antibiotics end up in the water - which they generally do - you're creating an ideal environment to select for resistance in every bacterium in the earth and waterways. And remember, bacteria share genes - what one can resist, pretty soon all can resist.

    From an evolutionary perspective, it's frankly insane to use antibiotics for any purpose other than treating serious disease in humans and beloved pets. Livestock don't intrinsically need antibiotics - they get dosed with them for purely economic reasons, because it's cheaper to keep them in an environment where they benefit from them.

    The fact that industry is slowly moving toward some sort of compromise is nice. But when you see your mother dying of an infection we could have cured ten years ago, you might not find cheap beef so comforting.

    1. I think we're actually in pretty close agreement here. I completely agree with you that antibiotics should only be used on sick animals -- as I said, "shouldn’t we also be talking about reducing [the animals'] stress to reduce their susceptibility [to disease] in the first place" rather than talking about how to cure that disease once it shows up?

      I'll disagree with you about the relevance of veterinarians vs evolutionary biologists to the argument, though I suspect that disagreement is just going to come from our different perspectives. Biologists may understand the microbiology better, but veterinarians understand the whole picture better, including the disease, the animal, and the producer. Now, I will say that the veterinary community has done a pretty poor job so far of managing this situation -- we haven't yet really committed to decreasing antibiotic use in any significant way, which I find frustrating. But I still think that we as a profession are best equipped with the knowledge needed to tackle the problem. If only we can take a step back, roll up our sleeves, and admit that the job won't be fun but must be done.

  2. Hey DZ.

    I'm actually cautiously optimistic that the trend in consumer pressure against antibiotics will end up actually being strong enough to make voluntary enforcement possible. Look at how rBST use is pretty much useless since Tillamook and Wal-Mart got on board, and how successful voluntary welfare audits have been for McDonalds chicken and beef producers.

    I think that rather than draft legal restriction guidelines that are slow to update, we need to reevaluate our organic requirements or allow food label claims such as "only clinically ill animals were given antibiotics in the creation of this product" or "no antibiotics used to enhance growth". This would put more marketing/consumer preference pressure on producers to avoid using antibiotics or ionophores for growth as consumers would have more purchasing power without having to pay a full organic price.

    I absolutely agree with encouraging more veterinarian involvement however. In addition to introducing more knowledge on the implications of product use, it's another way we can bring more veterinary involvement into food production.

    1. Hey Austin. Excellent points. Yes, I think the rBST lesson is a very relevant one. I'd say the organic requirements are not all that useful at this point -- maybe rather than trying to enter that morass, distributors could just make their own claims on the label as they did with rBST-free milk. So you tell me how to get that movement started, though! You have more connections in food production than I do, right?

    2. Well let's get a marketing proposal ready for NW Beef!