Drugs in Animal Food (Medicated Feeds)
Anyone who adds drugs to animal food creates medicated animal food. Just as each label claim for a new animal drug must be approved, a drug must be specifically approved for use in or on animal food. When the new animal drug application for use of the drug in or on animal food is approved, a notice is published in the Federal Register. The medicated feed must be labeled in accordance with the approved representative labeling.
A drug may be mixed only into feed for uses and at drug levels specifically permitted by the approvals and listed in the regulations (21 CFR Part 558). The entity manufacturing medicated feeds using Category II, Type A medicated articles; or manufacturing liquid and free-choice medicated feed containing a Category II drug; or liquid and free-choice medicated feed containing a Category I drug that follow an approved proprietary formula and/or specifications, is required to be registered with the FDA as a drug manufacturer and must hold an approved medicated feed mill license.
It is a violation of the Federal Food, Drug and Cosmetic Act (the FD&C Act) for drugs to be added to animal food for uses or at levels not specified in the approvals. Any individual authorizing the violation, as well as the individual illegally mixing the medicated feed, may be subject to regulatory action. Additionally, the feed itself may be subject to seizure. The agency is unlikely to consider taking a regulatory action when it encounters an extra-label use of medicated feed in minor species provided certain conditions are met, including the involvement of a licensed veterinarian.
Veterinary Feed Directives
The Animal Drug Availability Act of 1996 (ADAA) amended the FD&C Act to establish a new class of drugs – veterinary feed directive (VFD) drugs. A drug approved for use in or on animal food as a VFD drug can be fed to animals only under the professional supervision of a licensed veterinarian. The final rule covering the use and distribution of VFD feeds (medicated feeds containing VFD drugs) was published in the Federal Register on December 8, 2000. The second and current VFD rule was published on June 3, 2015.
The VFD process is straightforward in practice. A veterinarian, operating within the confines of a valid veterinarian-client-patient relationship, examines and diagnoses animal conditions and determines whether a condition warrants use of a VFD drug. If it does, the veterinarian will issue a signed VFD order containing information specified by regulation. As with any other drugs used in or on animal feed, extra-label use of a VFD drug is not permitted. The appropriate statement calling for no extra-label use is required to appear on every VFD order. The veterinarian completes and signs the VFD order, keeps the original, and provides one copy to the client and another to the distributor. All three parties – the veterinarian, the client, and the distributor – are required to keep the VFD order in their files for 2 years from the date of issuance. The VFD order allows the VFD feed to be issued to the client for feeding to the animals specified on the VFD.
Anyone intending to distribute VFD feeds must notify CVM prior to beginning distribution. The definition of a distributor includes the VFD feed manufacturer or anyone in the distribution chain who supplies VFD feed to an animal producer upon receiving a valid VFD order. The veterinarian could be a distributor of VFD feed. A VFD feed may not be fed without a signed, valid VFD. Although VFD feed may be sent down the distribution chain if the consignee, i.e., another distributor, provides the distributor with a signed acknowledgment letter affirming that the consignee will only issue the VFD feed to a client upon receiving a valid VFD order or to another distributor upon receiving the acknowledgment letter.