With debate brewing over the use of antibiotics in herd animals, supporters point to the value of responsible medicine.

The lines are drawn. Skeptics fear the continued use of antibiotics in herd animals will lead to antibiotic resistance. In fact, some have suggested that methicillin-resistant Staphylococcus aureus (MRSA)-tainted meat may be linked to farms that rely on antibiotics. In response, groups such as the National Cattlemen’s Beef Association and the American Veterinary Medical Association have backed the responsible use of antibiotics, maintaining it is necessary to protect both animal and human health.

Indeed, the use of antibiotics in herd animals is nothing new. The nearly-50-year-old practice has been closely monitored through the years, according to a spokesperson for the National Cattlemen’s Beef Association. By law, antibiotics must be administered according to their label, which is approved by the Food and Drug Association (FDA) for specific dosages and uses, she explains. The Association has published “A Producer’s Guide for Judicious Use of Antimicrobials in Cattle,” which highlights appropriate use of antibiotics on farms. (See related sidebar.) The guidelines promote such practices as avoiding the use of antibiotics that are important in human medicine and confining therapeutic antimicrobial use to proven clinical indications. Farmers are strongly encouraged to follow label instructions closely and take steps to minimize spills, ground run-off or other environmental contamination.

A complicated issue
Antibiotic resistance is a complicated issue, which has prompted a number of cattle producers and large animal veterinary professors to research the topic, according to the National Cattlemen’s Beef Association. A 2010 study conducted by Dr. H. Scott Hurd, DVM, PhD, Iowa State University associate professor and former Deputy Undersecretary Food Safety, USDA, responded to a recent CBS news segment about a possible link between antibiotic use on farms and MRSA-tainted meat.

For one, the type of MRSA that has been associated with livestock (strain 398) is unique and has not been found in humans, according to Hurd. In addition, the antibiotics used in pork today have not been associated with the development of MRSA. “Since antibiotics have been used in humans for 60 years and in livestock for about 50 years, if there was going to be an epidemic of resistance related to antibiotic use in agriculture, it would have occurred by now,” states Hurd. “Research demonstrates that when MRSA has been found on meat, it is present in extremely low levels. Because of this, the United States Centers for Disease Control and Prevention and the European Food Safety Authority both conclude that the likelihood of MRSA being spread by handling or eating meat is very low.

“Antibiotic use is one very important tool to maintain animal health in farms of all sizes and structures,” he continues. “Other tools used include hygiene, proper diet and nutrition, providing the proper environment and vaccination. Antibiotics help the animals grow healthier, improve animal well-being and help provide safe food.” Furthermore, contrary to accusations that some farmers feed their animals antibiotics to promote growth, Hurd says that is simply a “side benefit.” The primary reason farmers administer antibiotics is to help prevent disease and produce safer food, he notes.

He makes the point that, contrary to accusations by some Danish researchers, American farmers do not pump their farm animals with antibiotics. “This is evidenced by the grassroots initiative of Pork Quality Assurance Plus ®,” Hurd states. “This program helps guide farmers through proper and judicious ways to handle and use antibiotics responsibly.” The program has been in place for over 20 years, he adds.

Fact vs. fiction
As the debate over the use of antibiotics with herd animals ensues, some lawmakers are becoming increasingly vocal. In 2009, Rep. Louise Slaughter (D-N.Y.) introduced the “Preservation of Antibiotics for Medical Treatment Act” (PAMTA) in the House of Representatives. The legislation is designed to ensure the continued effectiveness of antibiotics for the treatment of human disease. Within two years of enactment, PAMTA would require the FDA to revisit the approvals it has issued for animal feed uses of seven classes of antibiotics that are central to human medicine. Any found to interfere with resistance would have their approvals rescinded.

The National Cattlemen’s Beef Association has taken exception to PAMTA, suggesting the legislation ignores the complexity of the antibiotic issue. In fact, the Association points out that “PAMTA would stop veterinarians and producers from preventing disease in livestock, which would ultimately harm animal welfare, animal health, food safety and food security.

“Prevention of disease is a cornerstone in both human and animal medicine,” the Association notes in its literature. “Taking away this tool undermines preventive medicine, and could ultimately lead to increased
antibiotic use.”
It is a myth that producers use antibiotics haphazardly or that unsanitary farm conditions increase the need for antibiotic use, according to the National Cattlemen’s Beef Association. For one, antibiotics only constitute one tool for keeping livestock healthy, it states. Proper care and nutrition, as well as genetic selection, are “the first line of defense” in ensuring animal health and limiting the need for antibiotic use. In addition, farms are clean and sanitary, the Association notes. Animals get sick more frequently when they are exposed to new animals, as is common on farms. Hence, the need for preventive medicine, argues the Association.

The next step
When it comes to defending judicious use of antibiotics among herd animals, the best approach is through education, says a spokesperson for the National Cattlemen’s Beef Association. For distributor reps, this means helping their veterinary customers keep abreast of the issues in the news. “There is a lot of misinformation in the media and public about who and what the beef industry is,” she says. “With the change in the [presidential] administration, there are new political appointees at the Food and Drug Administration who do not have a background in veterinary medicine or come from the livestock industry.

“All [who are] involved in livestock and poultry production need to help educate policy makers as well as the media and public about our processes and the science that backs them up.”

Sidebar 1:

A Producer’s Guide for Judicious Use of Antimicrobials in Cattle

1. Prevent problems: Emphasize appropriate husbandry and hygiene, routine health examinations, and vaccinations.

2. Select and use antibiotics carefully: Consult with your veterinarian on the selection and use of antibiotics. Have a valid reason to use an antibiotic. Therapeutic alternatives should be considered prior to using antimicrobial therapy.

3. Avoid using antibiotics important in human medicine as first line of therapy: Avoid using as the first antibiotic those medications that are important to treating strategic human or animal infections.

4. Use the laboratory to help you select antibiotics: Cultures and susceptibility test results should be used to aid in the selection of antimicrobials, whenever possible.

5. Combination antibiotic therapy is discouraged: Unless there is clear evidence this practice is beneficial.

6. Avoid inappropriate antibiotic use: Confine therapeutic antimicrobial use to proven clinical indications, avoiding inappropriate uses such as for viral infections without bacterial complication.

7. Treatment programs should reflect best use principles: Regimens for therapeutic antimicrobial use should be optimized using current pharmacological information and principles.

8. Treat the fewest number of animals possible: Limit antibiotic use to sick or at risk animals.

9. Treat for the recommended time period: To minimize the potential for bacteria to become resistant to antimicrobials.

10. Avoid environmental contamination with antibiotics: Steps should be taken to minimize antimicrobials reaching the environment through spillage, contaminated ground run off or aerosolization.

11. Keep records of antibiotic use: Accurate records of treatment and outcome should be used to evaluate therapeutic regimens and always follow proper withdrawal times.

12. Follow label directions: Follow label instructions and never use antibiotics other than as labeled without a valid veterinary prescription.

13. Extralabel antibiotic use must follow FDA regulations: Prescriptions, including extra label use of medications, must meet the Animal Medicinal Drug Use Clarification Act (AMDUCA) amendments to the Food, Drug, and Cosmetic Act and its regulations. This includes having a valid veterinary-client-relationship.

14. Subtherapeutic antibiotic use Is discouraged: Antibiotic use should be limited to prevent or control disease and should not be used if the principle intent is to improve performance.

Guidelines 1-13 were adapted from American Veterinary Medical Association (AVMA), American Association of Bovine Practitioners (AABP) and Academy of Veterinary Consultants (AVC) Appropriate Veterinary Antibiotic Use Guidelines.
Source: The National Cattlemen’s Beef Association.