UNDERSTANDING DRUG USE IN THE DAIRY ENTERPRISE
JUSTIFICATION
As an owner, manager or employee of a dairy enterprise, it is your responsibility to know
the rules and regulations regarding drug use. This means that you must understand the drug label
and conditions of use for the drug/hormone. In addition, improper use of drugs is a costly waste
of dollars and labor. The possible effects of erroneous drug/hormone use are serious. They are:
1) It is illegal to improperly administer a drug to a food-producing animal.
2) Improper use can be harmful to the person administering the drug/hormone.
3) Improper use can be harmful to the animal.
4) Improper use can be harmful to the consumer of animal products.
5) Improper use can affect consumer attitudes and, therefore, can reduce consumption of
products. Markets can be negatively influenced.
Sloppy use of drugs/hormones is irresponsible and should not be tolerated. It is the
responsibility of every Animal Science graduate to be thoroughly familiar with the regulations
regarding drug/hormone use.
OBJECTIVES
1) To understand the differences between various drugs.
2) To intelligently read and understand drug labels.
3) To recognize possible difficulties in interpretation of drug labels.
DESRIPTION AND DEFINITIONS
Every commercial pharmaceutical used by dairy producers contains an instruction label
and usually some form of detailed label insert. As a manager of a dairy enterprise, you may be
required to oversee the use of various pharmaceuticals. You are also responsible for making sure
that drugs are properly stored and administered. Close communication between you and the
veterinarian is obligatory.
There are two basic categories of drugs used on dairy enterprises. One is the over-thecounter drug and the other is a prescription drug.
Over-the-counter drug
This is a product which can be purchased without a prescription. It can be found on the
shelves at feed stores, livestock supply stores, hardware stores and general stores. The following
characterize an over-the-counter-drug:
1) This product contains a label, which clearly explains its use.
2) Drugs cannot be used legally by dairymen for disease conditions not indicated on the
label.
3) They cannot be used for conditions not specified on the label.
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Prescription drug
Prescription drugs differ from over-the-counter drugs in that the prescription labels carry
the following statement. CAUTION: FEDERAL LAW RESTRICTS THIS DRUG TO USE
BY OR ON THE ORDER OF A LICENSED VETERINARIAN. This does not mean that
the veterinarian has to administer the drug. It means that the veterinarian must show documented
evidence that he has authorized this drug to be used properly. In addition to the manufacturer’s
label, each prescription drug must have an additional label affixed to it. The label must contain
the following:
1) The name of the prescribing veterinarian. Clinic or practice names are not acceptable.
2) Each container must be labeled. Labeling cases or bulk packs is not acceptable.
Labels and/or product inserts on prescription drugs contain detailed information on the
following:
1) description
2) safety and toxicity
3) metabolism
4) instructions for use
5) warnings, precautions, possible adverse reactions
6) dosages and administration
EXTRA LABEL USE (ELUD)
Use of a drug in a manner which is not specified on the labels is defined as extra label
use. Extra label use is a decision that must be made by the veterinarian. Any ELUD must
contain a label bearing the name and address of the veterinarian. Examples of extra label use
include:
1) Use of a drug which is not approved for use in a class of animal, i.e., Banamine for
cattle.
2) Alteration of doses. For example, label indicates that 1 ml per 100 lb body weight but
3 mg/100 lb is prescribed.
Regardless of authorization by a veterinarian, it appears that the final legal responsibility
for drug use rests with the producer. (See attached article entitled “Serious Drug Law
Inequities.”)
Attached you will find copies of label inserts from a drug. Study these inserts carefully
and answer the following questions. You may have to consult the Physicians’ Desk Reference or
the Veterinary Pharmaceuticals and Biologics to obtain some of the information. The
Physicians’ Desk Reference (PDR) and the Veterinary Pharmaceuticals and Biologicals (VPB)
are excellent reference books on drugs and biologics that are approved for use in humans and
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animals, respectively, by FDA. Both references index products by manufacturer, product and
category. This allows for easy reference when full information on a product is not known. In
addition, both specific and general information on each product is given; most often, more
information than is included on the product label. Thus, when additional information on a
product’s chemical nature, method of function, efficacy, and spectrum of activity, are needed,
these references should be consulted. They can be found in the reference section: PDR – call
#RS75P5; and VPB – call #SF917C56.
UNDERSTANDING THE LABEL
The list of questions below are intended to serve as guidelines for each drug. You
should be able to answer any questions about each drug that is used on the dairy enterprise.
1. Who can use the drug?
2. What kind of animal can receive the drug? (lactating, dry, growing)
3. What are the age restrictions?
4. What are the maximum frequencies of administration?
5. What are the doses? Why would doses vary?
6. How does the drug work? i.e., What physiology does it change or alter?
7. Are there any withdrawal periods required for meat or withholding times for
milk? If so, what are their minimums?
8. What are the major precautions in using this drug?
9. What are the routes of administration?
10. Does the drug pose a health risk for any individual user? If so, what type of
individual user is at risk?
11. Are there possible adverse reactions that the animal will experience when
receiving this drug?
12. How should the drug be stored?
13. What is the expiration date on the drug?
14. Will the action of this drug interfere with that of another?
15. If you have questions and/or problems, who do you contact?
STORAGE
It is required that drugs for lactating cows and nonlactating cows (Dry cow and heifers)
be stored in separate places. This includes drugs that must be refrigerated. Separate, labeled
shelves in cabinets or refrigerators are satisfactory. Items such as fluids, vitamins, mineral
preparations, topical products and vaccines can be stored in either area.
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