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Navigating Livestock Antibiotic Regulations

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Publication Number: P3924
View as PDF: P3924.pdf

Antibiotics play a vital role in public health, and maintaining their effectiveness is essential. When antibiotics are used incorrectly or in excess, there is a threat of antibiotic resistance. Resistance is a serious concern that affects both humans and animals. Several antibiotics used in livestock production also play an important role in human medicine. The Food and Drug Administration (FDA) has issued guidelines (referred to officially by guidance number) for these products, which impacts how antibiotics are sold and used in animals.

As livestock producers, we always strive to keep our animals healthy, but sometimes antibiotics are necessary for unforeseen illnesses or injuries. This publication contains information for navigating livestock antibiotic regulations based on guidance from the FDA.

FDA Guidance #263: OTC Antibiotics

Medically important antibiotics are coming under veterinary oversight. This means antibiotics that were previously sold over the counter (OTC) will now require a prescription from your veterinarian.

This guidance will roll out over time, so many livestock producers may not see an immediate impact. According to this guidance, as of June 11, 2023, all new, affected products entering the marketplace must have prescription labeling. This means products manufactured after this date will require a prescription to purchase. If a store has stock on hand, they will be able to sell those products OTC until their inventory is depleted. Be mindful of expiration dates when purchasing any livestock health product. Do not plan to “stock up” as many products may expire before they can be used.

You can still purchase livestock antibiotics at many of the places you currently do or through your veterinarian. Online sources are also an option with a valid, veterinary prescription.

Some common affected products include:

  • Oxytetracyclines
    • Injectables: Liquamycin LA-200, Noromycin 300 LA, Bio-Mycin 200, Agrimycin 200, etc.
    • Boluses: Terramycin Scours Tablets, OXY 500 Calf Boluses
  • Penicillins (Penicillin G procaine, penicillin G benzathine)
    • Injectables: Penicillin Injectable, Dura-Pen, Pro-Pen-G, Combi-Pen 48, etc.
    • Intramammary tubes: Masti-Clear, Go-dry, Albadry Plus
  • Sulfa-based antibiotics (Sulfadimethoxine, sulfamethazine)
    • Injectables: Di-Methox 40%, SulfaMed 40%
    • Boluses: Albon, Sustain III Cattle & Calf Boluses, Supra Sulfa III Cattle & Calf Boluses
  • Tylosin
    • Injectables: Tylan 50, Tylan 200
  • Cephapirin, cephapirin benzathine
    • Intramammary tubes: ToDAY and ToMORROW

Click here for a full list of affected products.

FDA Guidance #213: The Veterinary Feed Directive (VFD)

The FDA has eliminated label claims for feed-through antibiotics for production purposes (feed efficiency or weight gain), and this guidance, which was revised since its initial implementation, now requires a prescription for therapeutic uses in feed and water.

This rule initially went into effect on January 1, 2017, and in March 2019 the FDA revised the initial rule based on stakeholder feedback and comments.

Copies of a VFD should be kept for a minimum of two years, and your feed store will require a current VFD before purchasing a medicated feed. As a reminder, you must follow the label directions for feeding any medicated feed.

Examples of products that would require a VFD include medicated mineral-containing chlortetracycline for control of anaplasmosis or a starter feed for high-risk calves that contains chlortetracycline and decoquinate. Click here for a list of all products and their approved combinations.

What should a livestock producer do in response to this guidance?

  1. If you do not have a good working relationship with your veterinarian, now is the time to develop one! Fellow cattlemen are a good resource for finding a large animal veterinarian near you. Connect with other cattlemen by attending your county cattlemen’s meeting, which is often organized through your local MSU Extension office.

Alternatively, you may search for Mississippi Veterinary Medical Association (MVMA) members under the “for the public” section. Add your county and species from the drop-down menus to search the membership list for veterinarians in your area. This list encompasses veterinarians who are members of the MVMA, but it may not include all veterinarians in Mississippi. Many large animal veterinarians cover a multi-county area, so a search in a nearby county might also yield results.

  1. Develop a valid veterinarian-client-patient relationship (VCPR). A VCPR is legally defined and required for your veterinarian to write prescriptions. It means that your veterinarian is familiar with your herd management protocols and can write prescriptions and certificates of veterinary inspection (CVI).
  2. Work with your veterinarian to develop a herd health plan. Then, have your veterinarian write prescriptions for the antibiotics and other products you need for the health of your livestock.

Remember, this does not mean a veterinarian has to administer every antibiotic given on your farm. The goal is to have their input on which antibiotics you use in certain instances. Often your veterinarian may recommend a more effective product that works in a shorter amount of time or a lower dose than was used in the past when OTC products were available. This is a win for combatting antibiotic resistance and a win for animal care.


Food and Drug Administration. Antimicrobial Resistance. Accessed June 6, 2023.

Food and Drug Administration. GFI #263: Frequently Asked Questions for Farmers and Ranchers. Accessed June 5, 2023.

Food and Drug Administration. FACT SHEET: Veterinary Feed Directive Final Rule and Next Steps. Accessed June 5, 2023.

National Cattlemen’s Beef Association. Updated Antibiotic Guidelines. Accessed June 6, 2023.

The information given here is for educational purposes only. References to commercial products, trade names, or suppliers are made with the understanding that no endorsement is implied and that no discrimination against other products or suppliers is intended.

Publication 3924 (POD-07-23)

By Brandi B. Karisch, PhD, Associate Extension/Research Professor, Milton Sundbeck Endowed Professor; and Libby Durst, Extension Associate, Animal and Dairy Sciences.

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Portrait of Dr. Brandi Bourg Karisch
Assoc Extension/Research Prof
Beef Cattle, Nutrition, Management, Health
Portrait of Ms. Libby Suzanne Durst
Extension Associate II

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Portrait of Dr. Carla L. Huston
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