Setting the Story Straight on “Human Antibiotics” in Animals: Expert Q&A

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From company announcements to government reports, there’s more attention than ever on the use of antibiotics in animals, different antibiotic types, and what producers and the FDA are doing to maintain human and animal health. There are a lot of terms flying around, so we spoke to Justin G. Bergeron, BVMS at the Veterinary Public Health and Preventive Medicine, Resident, University of Minnesota Center for Animal Health and Food Safety (CAHFS), to get some answers.

FACTS Followers: What do news outlets mean when they say “human antibiotics?” Why are they different?

Justin G. Bergeron, BVMS: Antibiotics work against bacteria, regardless of whether the body that bacteria is affecting is a human or an animal. Some antibiotics are better for humans, and some are better for animals. This is, in part, because of the different side effects that a given antibiotic can have in different species. Many antibiotics can be toxic to the human or animal taking them because they affect other organs and tissues, as well as the bacteria they are designed to fight. This is why some antibiotics are labeled “For dog use only,” or “For human consumption only.” Other antibiotics work well in many species and can be used at different dosages to fight the same kind of diseases in different species. For instance: dogs, horses, guinea pigs, and humans can all take doxycycline.

FACTS note: According to Dr. Richard Raymond, former Undersecretary for Food Safety at US Department of Agriculture (USDA), less than one percent (0.3%) of veterinary antibiotics are of the same class of antibiotics also used in human medicine, and they are used only for the treatment of disease.

FACTS: What are the different types of antibiotics and why do they matter for antibiotic stewardship?

JB: Antibiotics are separated into different classes based on how they interact with the bacteria they treat. As science has progressed we have been able to find more and more classes of antibiotics, so now there over a dozen different classes. Some of the older classes of antibiotics have been improved and now have new generations.

Within each class of antibiotics, there are sometimes many different individual antibiotics. Antibiotics within the same class all have roughly the same method of action (the way they kill or subdue the bacteria), they just ‘specialize’ in different bacteria in different locations of the body.

The key to utilizing antibiotics effectively and sustainably is knowing which antibiotic works the best on the disease-causing organism you are trying to fight. This is what it means to be an antibiotic steward: selectively choose the right antibiotic to control the specific disease you are fighting.

FACTS: What does it mean for antibiotics to be “medically important in humans” and what is the significance of phasing these antibiotics out of use in animals, from a food safety perspective?

JB: Antibiotics that are deemed “medically important in humans” are antibiotics that, if a large number of bacteria were to become resistant to them, would pose a public health risk.

The FDA has provided guidance on phasing out growth promotion uses “medically important” antibiotics from food-producing animals. These drugs are deemed important because they are also used to treat human disease on a routine basis. By phasing out these specific antibiotics’ daily use, there are fewer opportunities for the bacteria in the animals to develop resistance to the antibiotics.

FACTS: What do consumers need to know about antibiotic use in food production?

JB: It is important to remember that antibiotics are important for an animal’s health and wellbeing. When humans are sick, we need to take the appropriate medication to get better. Animals have the same need. Animals are not super heroes, they occasionally get sick and hurt through everyday living, just like us. In these instances, it is important to treat animals appropriately including giving them antibiotics, if needed. Then, animals’ milk and meat are withheld from the food system until antibiotics have fully cleared the animals’ systems.

FACTS: Why are antibiotics important to the food system, and what do you think is the future of antibiotic use on farms?

JB: Antibiotics are crucial to the food system because they allow us to keep animals healthy. Without a large number of healthy animals there will not be enough food to meet our needs.

I believe the future of antibiotics on farms will evolve to an even more mature form of antibiotic stewardship than we’re currently practicing. I believe that there will be even more bacteria identification on farm. This identification will be in conjunction with continually improving animal husbandry, to reduce the overall amount of antibiotics needed.

FACTS: How has agriculture used innovation and made progress in improving antibiotic stewardship?

JB: There have been great strides in our agriculture sector to improve antibiotic stewardship. We are continually identifying the most common bacteria-causing conditions. Once that bacteria is known, then the right antibiotic can be used. We are also frequently identifying the exact bacteria causing a disease and even finding out exactly what antibiotic is best to use in that individual case.

Additionally, we are reducing the overall amount of antibiotics used by changing our production practices. A lot of work has gone into animal housing and handling to reduce the level of disease found in our production animals. This effort has been paying dividends by significantly reducing reoccurring disease issues. For instance, by changing the stall formation and bedding type for a set dairy cows, you can reduce the number of cases of mastitis in the herd. This will reduce the number of times that antibiotics are used to treat the mastitis.

See also this interview with Morgan Scott of Texas A&M University.