Basic Guidelines of Judicious Therapeutic Use of Antimicrobials in Swine

(Approved by the AASV August 30, 2023)

AASV Position Statement

Judicious therapeutic use of antimicrobials is a core principle of the broader goal of antimicrobial stewardship. Antimicrobial stewardship involves maintaining animal health and welfare by implementing a variety of preventive and management strategies to prevent, control, and treat common diseases.

The American Association of Swine Veterinarians supports and is committed to the judicious therapeutic use of antimicrobials and the core principles of antimicrobial stewardship.^1,2 Judicious therapeutic use of antimicrobials in swine for the prevention, control, or treatment of a bacterial disease requires veterinary oversight in the context of a veterinarian-client-patient relationship (VCPR). Swine veterinarians are committed to using an evidence-based approach in making decisions to use antimicrobial medications; and then using antimicrobials judiciously, sparingly, and with appropriate evaluation of the outcomes of therapy. In addition, veterinarians should be involved in a farm’s health, well-being, and production decision-making processes to promote and provide guidance on the core principles of antimicrobial stewardship, in furtherance of public and pig health.

Judicious Therapeutic Use of Antimicrobials Principles for Swine Veterinarians

Following the core principles of swine health management is critical to prevent infections and reduce the need for antimicrobials.

Veterinarians should work with producers to ensure these steps are followed:

• Establish and follow all requirements of a valid veterinarian-client-patient relationship (VCPR).
  • Veterinarians should provide oversight regardless of the distribution system through which the antimicrobial was obtained, including prescription products and Veterinary Feed Directives (VFD).
  • Evaluate clinical outcomes and adjust therapy if needed.
  • Re-evaluate the need for additional antimicrobial use after corrective actions have been taken on identified co-factors.
• Implement, review, and audit preventive strategies to optimize pig health. These include husbandry, hygiene, biosecurity, routine health monitoring, welfare, and immunization.
• Recognize, investigate, and address the roles played by the various co-factors in the course of the disease(s):
  • Genetics,
  • Nutrition,
  • Housing, environment, and geographic location,
  • Management and production practices,
  • Health history and preventative strategies.
• Assess the need for antimicrobials.
  • Consider other management or therapeutic options prior to, or in conjunction with, antimicrobial therapy.
  • Evaluate and quantify the severity and prevalence of clinical signs.
  • Discern if individual treatment of ill or at-risk animals is sufficient to improve the overall group morbidity, mortality, and herd well-being; or if herd or group therapy is needed to control clinical outcome properly. 
  • Assess clinical signs and perform diagnostics to establish the differential diagnosis; and if possible, the definitive diagnosis.
• Follow the National Pork Board Pork Quality Assurance Plus³ (PQA Plus) Good Management Practices to help promote the proper execution of animal husbandry procedures and antimicrobial use.
  • Confirm proper storage and disposal of all medications.
  • Ensure and verify all equipment is calibrated for the delivery of therapeutic antibiotics.
  • Require records of all antimicrobial treatments.
• Optimize regimens for antimicrobial therapy by using current pharmacological science, principles, and regulatory guidance.
  • Use antimicrobials following careful review, with appropriate selection, of medication and regimen.
  • Use historical outcomes and clinical experience in the selection of antimicrobials.
  • Use adequate laboratory support, when available, for antimicrobial decision-making.
• Follow the label-specified withdrawal times to prevent violative residues for pork and pork products for the United States market.
  • Product withdrawal time is based on applying the product at the dosage, route, duration of administration, and frequency as specified on the label.
    • A generic product may have a different withdrawal time than its proprietary equivalent. Follow the specific product label for the medication used, including its label-specified withdrawal time.
    • If a withdrawal time cannot be determined, choosing an alternate medication may be the most appropriate course of action.
  • All veterinarians should work with their producer clients to ensure the use of animal health products do not result in violative residues.
  • If a withdrawal period cannot be determined for a product or compound, then is shouldn’t be used, especially when the residue requirement is zero and any detected would be violative.
• Changes to injection location, administration route, dose volume, duration, frequency, or simultaneous administration by multiple routes (i.e., feed, water, injection) constitute extra-label use as defined in AMDUCA⁴ in 21 CFR 530.
  • In the case of extra-label drug use (ELDU), obtain a scientifically based recommendation from a source like Food Animal Residue Avoidance Databank (FARAD) to prevent violative residues.^5,6,7
  • Medications can only be used in an extra-label manner under the confines of a valid VCPR.
• If pork or pork products are meant for export markets, extended withdrawal times may be required to be below importing country’s Maximum Residue Limit (MRL) requirements.  Use a scientifically based recommendation to establish a withdrawal time to prevent violative residues specific to the import market.

Resources

1. AVMA: Judicious Therapeutic Use of Antimicrobials
2. AVMA: Antimicrobial Stewardship Definition and Core Principles
3. Pork Quality Assurance® Plus
4. Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA)
5. FDA: The Ins and Outs of Extra-Label Drug Use in Animals: A Resource for Veterinarians
6. Food Animal Residue Avoidance Databank
7. AVMA: Extralabel Drug Use (ELDU) Algorithm

Approved by the AASV Board of Directors on August 30, 2023

This statement replaces previous AASV positions on Basic Guidelines of Judicious Therapeutic Use of Antimicrobials in Pork Production.