Antibiotics and Animal Health
The Food Journal
April 30, 2015
Farmers and veterinarians work together with an important common goal – to keep their animals healthy and happy. Good herd management helps prevent diseases before they develop and helps take care of animals when they are sick. Antibiotics are one tool that farmers and veterinarians can use to keep livestock and poultry healthy and protect our food supply.
But there is a lot of confusion about antibiotic use in animals, how antibiotics are regulated, and if antibiotic use is even necessary. There are also many questions about the overuse of antibiotics and antibiotic resistance – what many consider to be a growing global threat. In the midst of these questions, many food producers have altered the way they use antibiotics in their animals. Most recently, Tyson announced that it would stop feeding its chickens antibiotics that are used in human medicine. The FDA has been working to phase out certain types of antibiotics in farm animals since 2013.
Why Do Farmers Use Antibiotics in Food-Producing Animals?
Dr. John Maas, a rancher and veterinarian with a research degree in veterinaty microbiology and Diplomate for both the American College of Veterinary Nutrition and the American College of Veterinary Internal Medicine, says that the simple answer is that the use of antibiotics is essential to maintain animal health, assure animal welfare and comfort, and prevent certain diseases from occurring in the first place.
“Antibiotics have been a miraculous tool ever since the properties of penicillin were discovered last century. Many of the new antibiotics in both human medicine and cattle medicine continue that legacy of ‘miracle drugs’. Without the prudent use of antibiotics in cattle for disease treatment and disease prevention, cattle would become ill, suffer and die unnecessarily,” says Maas.
Ron Phillips, Vice President, Public Affairs, Animal Health Institute (AHI), says that antibiotics are needed as one tool in a much larger tool box of options that producers and veterinarians have to keep farm animals healthy.
“Keeping farm animals healthy is not only humane, but it is important to food safety. Research has shown that even animals that have subclinical disease can result in more foodborne pathogens on meat. Antibiotics are important tools for fighting bacterial disease,” says Phillips.
Indeed, the Animal Health Institute says that most antibiotics used in animals are used for therapuetic purposes of treating, controlling and preventing disease. According to AHI data, in 2007 about 87 percent of all antibiotics used in animals were used for these therapeutic purposes.
What’s the Debate About?
Controversy centers around the use of antibiotics for subtherapeutic reasons. Antibiotics are added to the feed and drinking water of food-producing animals to help them gain weight and improve feed efficiency.
“Farmers often mix low, subtherapeutic doses of antibiotics into animal feed to promote their growth, and to treat or prevent disease from spreading through their animals. This practice is intensified in large-scale farming, and the greatest increases in antibiotic use are expected to come from BRICS countries where meat consumption is rising,” says Dr. Ramanan Laxminarayan, co-author of a recent antibiotic use study by Princeton University, the International Livestock Research Institute, the Université Libre de Bruxelles and the Center for Disease Dynamics, Economics & Policy.
Laxminarayan says that veterinary antibiotic consumption is primarily driven by a shift in middle income countries from small scale farming to large industrial farming methods. This shift is due to increasing economic prosperity, particularly in Brazil, Russia, India, China and South Africa (BRICS), which has led to increasing demands for meat and animal products. The Princeton study reports that worldwide consumption in livestock could rise by 67 percent between 2010 and 2030.
Where Are We With Regulations?
In 2013, the FDA called on animal drug sponsors of approved medically important antimicrobials (antibiotics) administered through feed or water to remove from their product labels indications for use related to growth promotion (a subtheraputic use). They also called for the remaining therapeutic use of antibiotics to fall under the oversight of a veterinarian by December 2016. In 2014, the White House announced the National Strategy for Combating Antibiotic-Resistant Bacteria (CARB), underscoring the need to address antimicrobial resistance. In February 2015, the U.S. Food and Drug Administration announced its second progress report on its strategy to promote the judicious use of antimicrobials in food-producing animals. But will these new regulations work? And are they even needed?
It’s important to understand that the regulations caution against the use of antibiotics as a growth promoter and not as a resource for helping cure sick livestock, says Katie Sawyer, a fourth-generation farmer in Central Kansas who, along with her husband Derek, grows corn, soybeans, wheat and grain sorghum on their irrigated and dryland farm. The use of antibiotics as a tool for helping animals return to health is still very much supported by the FDA.
“Using antibiotics in the feed does not harm the animal. Producers who use antibiotics for any reason keep records and follow the withdrawal period guidance. These ensure animals entering the food system do not have antibiotics in their system. The FDA also monitors all processing plants to ensure any milk or proteins sold do not contain any level of antibiotics,” says Sawyer.
What Will the Outcomes Be?
Maas points out that there is a mistaken assumption that by decreasing the amount of antibiotics used in raising cattle there will be a decrease in antibiotic-resistant bacteria that can cause disease in people. There is no evidence that this cause-and-effect relationship exists; that said, the amount of antibiotics used will be significantly decreased.
“We will just have to wait and see. There are many other changes occurring in the way antibiotics are used in hospitals that will undoubtedly help to decrease the problems of antibiotic-resistant bacteria in human patients. Additionally, there are other changes made regarding the manner in which antibiotics are used in non-hospitalized human patients that may have great impacts on preventing antibiotic resistance,” says Maas.
The impact of the new FDA regulations will not be clear for another year or two, says Laxminarayan. At present, the regulations have stimulated major manufacturers of veterinary antibiotics to change their labeling to exclude growth promotion as a permitted use, which will eventually make application for that purpose illegal.
“Recently several large companies, including McDonalds, Chick Filet and Costco, have made voluntary commitments to reduce the use of meat from animals treated with antibiotics, in part due to consumer demand. This popular pressure may voluntarily phase out subtherapeutic use by producers,” says Laxminarayan.
Phillips says that the new regulations are intended to limit use of medically important antibiotics in food animals to what FDA describes as “judicious” use. As a result, medically important antibiotics will be used only to fight disease under the supervision of a veterinarian.
“As there are many factors that impact animal health in a given production system, it is difficult to tease out the effects of one change or another. Certainly the elimination of antibiotics for growth promotion puts pressure on production, meaning it may take more feed and other resources to get the same level of production from a given animal. From Europe we learned that the use of antibiotics for growth promotion was also preventing subclinical disease because the removal of growth promotion led to more disease and death,” says Phillips.
Sawyer continues, “The regulations will help continue the move the cattle industry has already made from using antibiotics for growth promotion to helping animals return to full health. Farmers and ranchers already provide quality care for their livestock and this will help further ensure that all producers are raising healthy animals and providing a safe and affordable food supply for consumers.”
How Concerned Should We Be About Drug Resistance?
Maas says that the issue of antibiotic resistance is real and one all health professionals need to be concerned about – whether they are physicians, veterinarians, dentists, or pharmacists. It is most important, he says, that we monitor the antibiotic-resistant bacteria, not simply the amount of drugs used as there may be no correlation or cause-and-effect relationships.
“Whether you are a patient or a cattle producer, you have a responsibility to use these important drugs in an appropriate manner. We will not make progress by ‘finger-pointing’ or ‘scapegoating’ individual groups or sectors. We all have a responsibility to work together to find viable strategies and solutions. The idea that antibiotic resistance is solely caused by the way these drugs are used in beef operations, though, is without merit and would be a poor assumption for making singular policy regarding decreasing resistance problems in human medicine,” says Maas.
Laxminarayan says that there is a great deal of evidence showing that the use of antibiotics in animals generates antibiotic resistance in animals, just as it does in humans. That fact is not in doubt, he says, but the mechanics of transmission of resistant bacteria from animals to humans are complex and work along many pathways.
“There is evidence that resistant bacteria and resistance genes are transmitted directly from farm animals to people in direct contact with them, including farm and slaughterhouse workers. We also know that bacteria – including resistant bacteria – are transmitted through the consumption of contaminated animal products and likely through the environment. However, the extent to which resistant bacteria found in humans originates from animals is still unknown since there is constant movement of bacteria back and forth between animals and humans. Given that transmission through these routes is possible, the use of veterinary antibiotics and the growth of resistance in animals certainly impacts human health, but we are still finding out how much,” says Laxminarayan.
What Do Consumers Need to Know?
Maas says that consumers can expect to pay a little more in restaurants or at the store, but quality will not suffer.
“We have been raising beef cattle in a similar manner over the last 30 years and the new regulations will affect only a small portion of the overall process. Antibiotics will not be allowed to be labeled or used to increase feed efficiency or growth rates. This will decrease the efficiency of beef production somewhat, but will not affect cattle health or cattle welfare,” says Maas. “U.S. beef is the safest and healthiest beef product on the planet and U.S. cattle producers are excellent stewards of their cattle and of the environment.”
Phillips says that there are a number of protection programs built into law to ensure proper antibiotic use in food production animals. Antibiotics go through a stringent approval process at FDA, and, in the case of antibiotics in feed, the FDA-approved label must be followed. The USDA Food Safety and Inspection Service also tests meat for antibiotic residues.
“The extremely low level of violative residues found in meat is an indicator that the federal labels that require a withdrawal time are effective and are being followed. FDA’s recent milk residue testing program demonstrated similar results. We are now adding another layer of protection by requiring a licensed veterinarian to be involved in the use of medically important antibiotics,” says Phillips.
Sawyer adds, “My farm welcomes more than 500 new calves into the world each winter and spring. With the constant change in weather and temperatures, we inevitably have at least one calf fall ill. We use multiple tools to help the animal return to health including moving the animal to a warm, enclosed area, providing extra fluids and finally, as a last step, using antibiotics. We have to stop the fear mongering and look at the facts and evidence on the issue. Animal welfare is of the utmost concern for us and without antibiotics, we would find ourselves unable to help our sick animals.”