Superbugs and the Zombie Apocolypse….

Antibiotic Apocalypse! Superbugs resistant to Everything! What will we do when medicines no longer work?! These kind of headlines make it appear like the end of the world may in fact be close at hand. (do you have your zombie apocalypse team in place?) Worse than this kind of media sensationalism are food companies who have turned this important issue into a fear based marketing campaign. You know who I’m talking about….

The use of antibiotics in livestock production has been a growing concern for consumers due to the increase in illnesses and deaths caused by antibiotic resistant bacteria. It is estimated that two million illnesses and 23,000 deaths annually in the US are a result of antimicrobial resistance. While this is, understandably a major concern for consumers, they have unfortunately been mislead by non-credible sources who choose to ignore the up side of antibiotic use in livestock production. It’s important for consumers to hear both sides of the antibiotics argument to fully understand the benefits and risks of antibiotic use on farms.

We have used antibiotics in livestock  for years. In the 1970’s, monensin (an antibiotic) was fed to chickens to help prevent coccidiosis (a bacteria). The chicken manure was used as fertilizer on cattle pastures and the farmer noticed that the cattle grazing the pastures that had chicken manure grew faster than the cattle grazing pastures with other fertilizer. This lead to the scientific discovery that certain ionophores (antibiotics) promote increased growth and improved feed efficiency in production animals. This has become important in recent years as we are tasked with feeding a growing global population with a limited land base.

Using antibiotics sub-therapeutically not only enhances feed efficiency and promotes healthy growth, it also ensures that the livestock is healthy for human consumption. Feeding certain antibiotics leads to increased nutrient absorption and reduces the pathogens shed into the environment. By increasing the feed efficiency and bioavailability of nutrients, production animals are able to use feed more efficiently, live healthier, and this helps eliminate food-borne pathogens that could contaminate the food supply. In a 2014 study, researchers found that over one hundred antimicrobials play an important role in prevention, treatment, and control of animal diseases caused by pathogens. Not only did they find that antibiotics improved the overall health of livestock, they found that feeding some antimicrobials to animals could reduce the emission of greenhouse gases by encouraging normal fermentation, thus aiding in reducing air pollution.

When thinking about the risks of antibiotic use in livestock, it is important to understand the actual risks versus the perceived hype. Consumers have been told that the rise in antimicrobial resistance has been linked to their over-use in livestock production and both Canada and the US have begun phasing out antibiotic use in production agriculture. While this makes it appear obvious that excessive use of antibiotics in livestock is to blame, it’s not really that clear. The Center for Disease Control (CDC) in the US has found that, in human medicine, antibiotics are the most commonly prescribed drug, and up to 50% of the time the antibiotics are prescribed when they are not needed! In a 2013 release, Dr. Tom Frieden, CDC Director stated that “right now the most acute problem is in hospitals, and the most resistant organisms in hospitals are emerging in those settings because of poor antimicrobial stewardship among humans”. The other thing to keep in mind is that majority of antibiotics used in livestock production are ionophores, which are a whole class of drugs that are NEVER used in human medicine.

So, while responsible antibiotic use on farms continues to be important, it should also not be the convenient scape goat for the rise in antimicrobial resistance. As an industry, we have a responsibility to properly administer and prescribe medications for animals when required. Antibiotics will always be a tool to keep livestock healthy, and the fight against superbugs is real. There are things we can do to monitor and lessen the impact of the livestock industry on resistant bacteria, just like there are ways human medicine can do better. One thing is clear: the fight against antimicrobial resistance depends on proper education and information and is not helped by misleading marketing and fear mongering. You know who I’m talking about…..


Broadway, P.R., Carroll, J.A., & Callaway, T.R. (2014). Antibiotic use in Livestock production. Agric. Food Anal. Bacteriol., 4, 1-10. Retrieved from

Centers for Disease Control and Prevention. (2015). Antibiotic/antimicrobial resistance. Retrieved from

Committee to Study the Human Health Effects of Subtherapeutic Antibiotic Use in Animal Feeds, Division of Medical Sciences, National Research Council. (1980). The effects on human health of subtherapeutic use of antimicrobials in animal feeds. Retrieved from

Hao, H., Cheng, G., Iqbal, Z., Ai, X., Hussain, H.I., Huang, L., Yuan, Z. (2014). Benefits and risks of antimicrobial use in food-producing animals. Frontiers in Microbiology, 5,288. Retrieved from

U.S. Food and Drug Administration. (2015). Antimicrobial Resistance. Retrieved from

Weber, G. (2006). FDA approvals ensure safe antibiotic use. Issues Update, 15-16. Retrieved from


2 thoughts on “Superbugs and the Zombie Apocolypse….

  1. Wendell…interesting post. What’s your take on the emerging practice of Selective Dry Cow Therapy to control antibiotic use? I was speaking with some of the Profs at the Ontario Vet College and they were suggesting that legislation may be on the way forcing Canadian producers in that direction. I know it’s already well established in Holland and UK.


    1. Thanks. I think there are some interesting new technologies available such as immunity boosters that make this much more feasible. Some producers are choosing not to dry treat low risk cows and having good success. The danger, however, is that by not using a preventative antibiotic therapy, more cows may develop clinical cases of mastitis requiring antibiotics at a treatment level and put the cows at greater risk. I do think we will see more non-antibiotic tools developed in this area.


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