Chris Rademacher, Iowa State University, Pork Management Conference, June 14-17, in Clearwater, Florida.

1. Antibiotic Use in Animal
Agriculture- Where are we going?
Chris Rademacher, DVM
ISU Swine Extension Veterinarian

2. Agenda
• Overview of Antibiotic Use in Livestock.
• FDA Guidance 209/213/VFD regulations
• Impact on Livestock Production

3. How do we balance the public desire for less antibiotic usage with
protecting animal health and well being!!

4. Perception vs Reality
Antibiotics

5. How do food production veterinarians “judiciously” use antibiotics
• When doing necropsies (autopsy) on pigs with disease,
organs are collected, sent do a diagnostic lab and sampled for
bacteria.
o The bacteria are grown on agar plates and identified.
• Then discs with antibiotics are placed on the plates to see
what antibiotics inhibit bacterial growth (sensitivities) or use
in broth to establish MIC
• Then we can decide which antibiotics to treat with in order to
be successful.
o This minimizes the amount of antibiotics used by avoiding
rotating through antibiotics until finding one that works.

6. So how did we get here??
Concerns about:
• Role of antibiotic use in animal medicine in creating
resistance issues in human medicine!!
• No definitive link has been established!!

7. Antibiotic Resistance is a Complicated Issue
• For a start, the potential development of antibiotic resistance is a
complex issue. Animal health and public health experts are in
agreement that antibiotic resistance has occurred for millennia,
completely independent of human involvement and the advent of
modern-day antibiotics.
– Bacteria from Colobus monkeys in the Amazon
– Bacteria in caves just newly discovered by human beings

8. Antibiotic Resistance is a Complicated Issue
• However, the use of antibiotics, whether in human health, animal
health or agriculture, applies potential selection pressures for the
development of antibiotic resistant bacteria.
– Using antibiotics can select for a population for resistant bacteria

9. Antibiotic Label Indications for Use
• Treatment
o Defined as the use of an antibiotic for the treatment of animals showing
clinical signs of disease.
• Control
o Defined as the use of an antibiotic for the treatment of a group of animals
where a percentage (usually >10% are sick) and the remainder of the group
are not showing clinical signs (yet).
• Prevention
o Defined as the use of an antibiotic in a group of healthy animals that are
known to be at risk for, or exposed to, disease agents (before clinical signs).
• Growth Promotion
o Improves growth or feed efficiency

10. Antibiotic Use in Swine by Route and Indication
Use and Route Treatment Control Prevention Growth
Promotion
Injectable X X
Water Soluble X X
Feed Grade X X X X
Treatment, Control, Prevention = Therapeutic
Growth Promotion = Non-therapeutic

11. Antibiotic Usage Reporting – FDA 2012
• Annually, each drug manufacturer must
report the sales and distribution of
antibiotics that are approved for use in food
animals.
• Is reported by pounds of active ingredient
• Limitations:
• Not actual usage data
• Some drugs approved for food animals
AND companion animals
• Veterinarians are authorized to change
dose in non-feed related antimicrobials
• Not species specific.
• Will be changed in 2017
95% of all antibiotic
usage is in feed and
water.

12. Antibiotic Usage Reporting – FDA 2012
• Most of the antibiotic usage
does NOT require a
prescription from a
veterinarian
• Rx/VFD = Veterinary
Oversight
• OTC = “Over the
Counter”
• No veterinary
oversight necessary
Most antibiotic usage does not
REQUIRE oversight by a veterinarian.

13. Antibiotic Usage Reporting – FDA 2012
• 2 drug classes represent
72% of the antimicrobial
usage in food producing
animals
• Tetracyclines – 41%
• Ionophors – 31%
• Non-medically
important

14. Antibiotic Usage Reporting – FDA 2012
• Overall trend for
antibiotic usage is
increasing over the past
4 years by 16%
• 2009-2012
• Water based antibiotic
usage is up as well.

15. Summary of FDA Guidance 209/213
1. Limits “medically important” antibiotics to therapeutic
purposes (to protect animal health and well-being).
– Therapeutic Purposes
• Treatment
• Control
• Prevention
2. Non-therapeutic uses of “medically important” antibiotics are
no longer permitted.
– Improved growth and feed conversion

16. Summary of FDA Guidance 209/213
3. Also states the importance of veterinary oversight into all on-
farm antibiotic decisions.
– Veterinary oversight will now guide all antibiotic decisions on the
farm.
• All “medically important” antibiotics used in mass medication
(feed/water) will have to be scripted (VFD/Rx) in their use.
– Eliminates “Over the Counter” usage of medically important
antibiotics used in mass medication (Feed and/or Water).
• No longer be able to purchase “medically important” antibiotics
(feed/water) without a prescription (VFD/Rx) from a licensed
veterinarian.

17. How do you determine if an antibiotic is “medically” important?
• FDA Guidance #152 (2003)
• Risk assessment for veterinary drugs creating
“potential” resistance issues for human medicine.
• All scientific assessments done to date have
demonstrated that the risk is negligible.
• Classified all antibiotics into 2 classes:
• Medically Important for Human Use
• Non-medically Important for Human Use

18. • Antibiotics that are already VFD or Rx based:
– avilamycin, florfenicol, tilmicosin; or Rx - Tylosin.
• Antibiotics that are not medically important:
– Ionophores (monensin, lasalocid, narasin (Skycis,etc. )
– Bacitracin (BMD, bacitracin zinc)
– Bambermycins (Flavomycin)
– Carbadox (Mecadox)
– Tiamulin (Denagard)
• Other drugs (that are not antibiotics), including:
– Anthelmentics: Coumaphos, Fenbendazole, Ivermectin
– Beta agonists: Ractopamine, Zilpaterol
– Coccidiostats: Clopidol, Decoquinate, Diclazuril
Antibiotics NOT affected by Guidance 209/213

19. Injectable and Oral Antibiotics For Use In Swine
Antibiotics - Oral/Water Med Antibiotics - Injectable
*Amoxicillin *Draxxin
*Aureomycin Sulmet *Duo-Pen, BP-48, Combi-Pen
Denegard *Excede for Swine
*Gentamicin Sulfate *Excenel
*Gen-Gard Soluble Powder *Gentamicin Piglet Injection
*Lincomycin Hydrochloride *Lincomix 25, 100, 300
*L-S 50 *Naxcel
*Neo 325, Neo-Med *Nuflor
*Nuflor 2.3% Concentrate *Penicillin G Procaine
*Oxytetracycline HCI SP-343, *LA-200, Duramycin 72-200,
Tetraoxy-HCA 280 Pennox, Maxium 200
*Penicillin G Potassium *Polyflex
*Pennchlor 64, Aureomycin *Tylan 50, 200
*SpectoGard
*Sulmet
*Tet-Sol 324, Duramycin 324
*TMZ, Sulfamethozazole,
Trimethoprim Oral
*Tylan
* Medically important for human use GFI #152
Yellow = Medically Important
Green = Non-medically Important
Example
based on a
typical swine
distribution
warehouse

20. Swine Feed Grade Antibiotics
Bacitracin Methylene Disalicylate
Bacitracin Zinc
Bambermycins
Carbadox
*Chlortetracycline
*Chlortetracycline/Sulfamethazine/Penicillin
*Chlortetracycline/Sulfathiazole/Penicillin
*Neomycin/Oxytetracycline
*Oxtetracycline
*Penicillin
Tiamulin
*Tylosin
*Tylosin/Sulfamethazine
*Virginiamycin
Yellow = Medically Important
Green = Non-medically Important
(BMD)
(Mecadox)
(CTC – Aureomycin/Pennchlor 64)
(OTC – Terramycin/LA 200/Pennox)
(Denagard)
(Stafac)
(Flavomycin)
Narasin (Skycis)

21. Drug* Manufacturer Dose Current Label
Lincomycin® Zoetis 20 g/Ton Increased rate of weight gain in growing-finishing swine
Tylan® Elanco 10-20 g/Ton Increased rate of weight gain in growing-finishing swine
Stafac® Phibro 5-10 g/Ton Increased rate of weight gain and improved feed efficiency
Neo-Terra® Phibro 10-50 g/Ton Increased rate of weight gain and improved feed efficiency
Aureomycin®
Pennchlor®
Zoetis
Pharmgate
10-70 g/Ton Increased rate of weight gain and improved feed efficiency
Terramycin® Phibro 10-50 g/Ton Increased rate of weight gain and improved feed efficiency
Pennox® Pharmgate 10-50 g/Ton Increased rate of weight gain and improved feed efficiency
Pennchlor SP® Pharmgate 250g/Ton Increased rate of weight gain and improved feed efficiency
So what swine feed grade antibiotic growth promotion claims will be phased out?
* Same for generic equivalents

22. Veterinary Feed Directive (VFD)
• Basically, it is a prescription for utilizing “medically important”
antibiotics in animal feed.
– Not technically a script, but functionally works the same
• It requires a VFD from a veterinarian who the producer has a
valid VCPR with for their operation.
• Veterinarian is responsible for filling it our correctly and then
sending a copy to the producer and the distributor (feed mill)
– All parties must retain copies for 2 years or reproduce them upon
inspection.

23. What’s involved in a Prescription?
• Veterinarian will need to issue a prescription (script)
in order to direct use for “medicated water”
• Script should include:
– Drug name and active Ingredient
– Concentration and dosage
– Route of administration
– Withdrawal time
• Producer needs to keep treatment records for 1 year after the
animal is treated.

24. What is a Veterinary- Client Patient Relationship (VCPR) ?
• It is an agreement between a veterinarian and
producer for the veterinarian to assume the
responsibility for making medical judgements for the
producers animals.
– States can have their own VCPR definitions, but they must
contain the following language, or it defaults to the federal
guidelines (21 CFR 530).

25. Federal Veterinary- Client Patient Relationship (VCPR)
• (1) A veterinarian has assumed the responsibility for making medical judgments
regarding the health of (an) animal(s) and the need for medical treatment, and the
client (the owner of the animal or animals or other caretaker) has agreed to follow
the instructions of the veterinarian;
• (2) There is sufficient knowledge of the animal(s) by the veterinarian to initiate at
least a general or preliminary diagnosis of the medical condition of the animal(s);
and
• (3) The practicing veterinarian is readily available for follow-up in case of adverse
reactions or failure of the regimen of therapy. Such a relationship can exist only
when the veterinarian has recently seen and is personally acquainted with the
keeping and care of the animal(s) by virtue of examination of the animal(s), and/or
by medically appropriate and timely visits to the premises where the animal(s) are
kept.

26. Impacts of regulations for swine industry
• Reduction in use of antibiotics for growth promotion
• More non-medicated diets
• Non-medically important growth promotion diets
• More veterinary oversight needed
• More of a challenge in other species, particularly beef cattle
• Challenges on prevention will be the proverbial “line in the sand”.
• Now we begin to threaten animal health and well being.

27. Summary
• FDA Guidance 209, 213, VFD already being implemented
• No growth promotion of medically important antibiotics
• More veterinary oversight into antibiotic usage (VFD and
Prescriptions for Mass Medications)
• VFD will be required for all “medically important antibiotics”
to be used in feed.
• These regulations will be fully into effect by January 1, 2017
• We have less than a year to get these changes in place.

28. Acknowledgements:
• Dr. Liz Wagstrom – NPPC Veterinarian
• Dr. Jennifer Koeman – NPB Veterinarian
• Dr. Mike Murphy – FDA/CVM
• Dr. Harry Snelson – AASV