Animals, like humans, are susceptible to bacterial and parasitic infections, and frequently require medications, or drugs to treat these various conditions. Veterinarians and producers are fortunate in that we have several antimicrobial drugs available to treat various infections in food producing animals. These antimicrobial medications have labels approved by the Food and Drug Administration (FDA). The product label includes important information such as indications, directions, route of administration, precautions, and withdrawal period. Deviations from following the label directions could result in altered effectiveness, potential toxicity to the animal and violative meat or milk residues.

The FDA recognizes that certain conditions may arise in which a drug will need to be used in an extra-label manner (extra-label drug use; ELDU) and recognizes the professional judgment of veterinarians in making those recommendations. Any ELDU of a FDA approved drug is by definition a prescription drug and requires the involvement of a licensed veterinarian. In order for ELDU to occur, a valid veterinarian-client-patient-relationship (V-C-P-R) must exist.

Briefly, the following must be met regarding a valid V-C-P-R and for a food animal veterinarian to prescribe the extra-label use of a medication:

1.) There is no approved new animal drug labeled for a particular condition or the new animal drug is clinically ineffective.

2.) The licensed veterinarian has assumed the responsibility for making medical judgments regarding the health of the animal(s) and the need for medical treatment.

3.) The licensed veterinarian has sufficient knowledge of the animal(s) to initiate at least a general or preliminary diagnosis of the medical condition.

4.) The licensed veterinarian is available for follow up in case of adverse reactions or failure of the regimen of therapy.

5.) The licensed veterinarian establishes an extended withdrawal period based on appropriate scientific evidence prior to marketing the animal or product (such as milk, eggs).

6.) The treated animal(s) must be properly identified and the identity is carefully maintained. Records of ELDU must be maintained by the veterinarian for a minimum of 2 years.

7.) The owner of the animal(s) agrees to follow the veterinarian’s instructions.

ELDU is limited to circumstances when suffering or death may result from failure to treat or when the health of the animal is threatened. ELDU is not permitted for production (growth, reproduction) enhancement, for reducing the treatment costs. While a veterinarian can legally prescribe many products for ELDU, there are some that are explicitly illegal for extra-label use. Many of these products are not labeled for any use in food animals, and should never be used for any reason. For others, the prohibition of ELDU means those products can only be used for the specific condition for which it is labeled, and should not be used for any other reason. Extra label use of feed medications is prohibited by FDA. The law requires that no violative drug residue may result from the ELDU.

Working with your veterinarian and establishing and maintaining a valid V-C-P-R will help assure a safe food supply for the consumer and the well-being of food producing animals. Additional information may be found at:

Source: D.L. Step, DVM, Associate Professor, Oklahoma State University Center for Veterinary Health Sciences