Prudent Use of Antibiotics in Beef Production
Keeping medically important antimicrobial drugs available to animal agriculture relies on judicious use at the grassroots level.
Cattle producers across the country have a keen understanding of the role antibiotics and antimicrobials play in ensuring the health and well-being of the animals under their care. Several layers of protection have been put in place to ensure antibiotics are used to keep animals healthy without harm to public health.
The U.S. Food and Drug Administration (FDA) approves drug labels, including routes of administration, duration of therapy, and doses. The USDA Food Safety & Inspection Service (FSIS), in turn, conducts tests to ensure beef entering the food supply does not contain violative antibiotic levels.
However, a rising level of scrutiny over the use of antibiotics and antimicrobials in animal agriculture has the beef industry on the defense and federal regulators in a mood to rewrite the rules over animal drug use. Underscoring the issue is the director of the U.S. Centers for Disease Control (CDC) Dr. Thomas Frieden. He surprised many in livestock agriculture last year by testifying that there is “strong scientific evidence of a link between antibiotic use in food animals and antibiotic resistance in humans.”
Subsequently, the FDA issued a “draft guidance” intended to reduce the development of resistance to medically important antimicrobial drugs which are widely used in food animal production to ward off disease and promote growth. U.S. Rep. Henry Waxman (D-CA) called the draft guidance “a good first step,” but stressed that more could be done to combat the problem.
Waxman directed USDA to work with livestock producers in addressing possible links between antibiotic resistance in humans to the use of medically important antibiotics in animals.
“USDA believes that it is likely the use of antibiotics in animal agriculture does lead to some cases of antibacterial resistance among humans and in the animals themselves, and it is important that these medically important antibiotics be used judiciously,” said John Clifford, DVM, USDA’s Animal and Plant Health Inspection Service (APHIS) deputy administrator for veterinary services.
“We need to work together to conduct research and develop new therapies that protect and preserve animal health, without increasing the risk of resistance to medically important antibiotics,” explained Clifford, adding that the agency must partner with producers, in addition to federal agencies, to facilitate the judicious use of antibiotics “in ways that are feasible to farmers and ranchers.”
“Using medically important antimicrobial drugs as judiciously as possible is key to minimizing resistance development and preserving the effectiveness of these drugs as therapies for humans and animals,” agreed Bernadette Dunham, director of the FDA’s Center for Veterinary Medicine. “FDA is committed to working with animal drug sponsors, the veterinary and public health communities, the animal agriculture community, and all other interested stakeholders in developing a practical strategy to address antimicrobial resistance concerns that is protective of both human and animal health.”
Practical and appropriate strategies
National Beef Quality Assurance (BQA) programs support science-based decisions regarding the safety and efficacy of antibiotics and antimicrobials used in animal agriculture, said Dee Griffin, DVM, University of Nebraska – Lincoln, Great Plains Veterinary Educational Center, and a member of the national BQA steering committee.
“BQA emphasizes that deviation from label directions could potentially cause lack of effectiveness for the disease being treated, toxicity to the animals, or a violative residue in food harvested from the animal,” said Griffin.
BQA Producer Guidelines for Judicious Use of Antimicrobials have been in place since 1987:
√ Avoid using antibiotics that are important in human medicine.
√ Use a narrow spectrum of antimicrobials whenever possible.
√ Treat the fewest number of animals possible.
√ Antibiotic use should be limited to prevent or control disease and should not be used if the principle intent is to improve performance.
Elizabeth Parker, DVM, National Cattlemen’s Beef Association (NCBA), said BQA programs stress that all cattle producers have an ethical responsibility, along with a compelling economic need, to use antibiotics in such a manner that the animals they raise do not carry residues that violate FDA standards.
A producer-veterinarian relationship is the first step in making sure that all cattle health products are used appropriately. Formally, this is known as a veterinary-client-patient relationship (VCPR).
The FDA considers a valid VCPR to exist when:
√ The licensed veterinarian has assumed clinical responsibility for the animals.
√ The owner of the animals has agreed to follow the veterinarian’s instructions.
√ The veterinarian has sufficient direct knowledge of the animals’ condition and their care.
√ The veterinarian is available for follow-up evaluation.
One aspect of a VCPR that often arises is extra-label drug use (ELDU). The Animal Medicinal Drug Use Clarification Act (AMDUCA) of 1996 enables licensed veterinarians to adjust the use of an FDA-approved drug other than as labeled when the health and well-being of that animal or group of animals is threatened. But, Parker explained that the law is clear: “ELDU shall not be considered if the purpose is for growth promotion, reproductive performance, or alteration of cost of therapy.”
This seems very straightforward, but there’s one very important point in the law, even if the rationale for ELDU is reasonable – ELDU must not lead to a violative drug residue. Additional conditions that must be met before ELDU may be legally considered are:
A careful diagnosis is made by an attending veterinarian.
There is no marketable drug specifically labeled to treat the condition diagnosed, or treatment at the dosage recommended by the labeling was found clinically ineffective.
Assurance that identity of the treated animal(s) is carefully maintained.
A significantly extended drug withdrawal is assigned to the animal(s) so that no violative residue occurs.
If the individual animal cannot be identified for the extended withdrawal time, then the extended withdrawal time must be applied to the entire group.
ELDU and feed additives
Feed additives must be used only according to the label instruction.
“Not even a veterinarian may legally prescribe or use drugs in feed in an extra-label manner,” said Mike Apley, DVM, Professor of Clinical Sciences, College of Veterinary Medicine, Kansas State University. “Also, feeding rations containing non-approved combinations of drugs is illegal.”
Producers are required by law to make all feed-additive use records available to an FDA inspector upon request. A good management practice is to include the exact times rations containing a feed additive were removed and the exact time a ration containing a different feed additive was delivered to the cattle. This helps the FDA inspector appreciate the diligence practiced to prevent cross-contamination of rations containing feed additives not approved to be fed in combination.
“It should be clear that the laws and rules are different for injectable drugs and drugs administered in the feed,” added Apley. Other questions about the legal use of over-the-counter and prescription drugs can be addressed by your veterinarian.
ELDU Requirements, as outlined by NCBA’s Elizabeth Parker, DVM:
• ELDU is permitted only by and/or under the supervision of a veterinarian.
• ELDU is allowed only for FDA-approved animal and human drugs.
• A valid VCPR is a prerequisite for all ELDU.
• ELDU is for therapeutic purposes only (animal’s health is suffering or threatened) – not drugs for production use.
• Rules apply to dosage-form drugs and drugs administered in water. ELDU in feed is prohibited.
• ELDU is not permitted if it results in violative food residue, or any residue which may present a risk to public health.
• FDA prohibition of a specific ELDU precludes such use.
ELDU Record Keeping Requirements*
• Identify the animals, either as individuals or a group.
• Animal species treated.
• Numbers of animals treated.
• Conditions being treated.
• The established name of the drug and active ingredient.
• Dosage prescribed or used.
• Duration of treatment.
• Specified withdrawal, withholding, or discard time(s), if applicable, for meat, milk, eggs, or animal-derived food.
• Keep records for two (2) years.
• FDA may have access to these records.
*BQA guidelines recommend keeping these records for all livestock treatments.
Additional sources:
Using FDA-Approved Medications: Common Scenarios – Mike Apley, DVM, Professor of Clinical Sciences, College of Veterinary Medicine, Kansas State University; Virginia Fajt, DVM, Clinical Assistant Professor, Texas A&M University and Chair of the Committee on Pharmaceutical and Biologic Issues of the American Association of Bovine Practitioners; and Dee Griffin, DVM, University of Nebraska – Lincoln, Great Plains Veterinary Educational Center.
Extra-Label Drug Use -- An Informational Outline of the Animal Medicinal Drug Use Clarification Act (AMDUCA) – American Veterinary Medical Association.