Therapeutic or "prescription" diets must be dispensed within a valid veterinarian-client-patient relationship. But why, when these diets do not contain prescription drugs? Are they ethical products—sold only through veterinarians by virtue of a manufacturer's voluntarily imposed sales policy? Why does the Food and Drug Administration Center for Veterinary Medicine require the VCPR?
AVMA staff posed those questions to Dr. William J. Burkholder from the Nutrition and Labeling Team, Division of Animal Feeds, FDA-CVM, for clarification.
According to Dr. Burkholder, there are no legal definitions for terms such as veterinary medical food products, therapeutic or prescription-type diets, or medical foods for animals. These products are, therefore, regulated as foods and/or drugs under the Federal Food, Drug, and Cosmetic Act. In his response, Dr. Burkholder wrote: "That the intended use of an article to alter disease is one legal definition of a drug is a fact that is neither well ingrained in veterinary students, nor widely recognized by veterinarians or the general public. However, it is a legal fact that drugs are defined by their intended use, not by their chemical composition, chemical properties, or dosage form."
Labeling and promotional materials associated with therapeutic diets establish their intended use as drugs under the definition in Section 201(g)(1)(B). Such articles are not exempted as drugs just because they also meet the definition of an animal feed/food.
"In essence, because none of the so-called veterinary medical food products have an approved NADA," Dr. Burkholder stated, "they are in violation of the Act (eg, are illegal products) because they have not been shown to be safe and effective for their intended use."
Through its enforcement discretion, the FDA allows these so-called VMF products to be regulated as food and marketed without an approved New Animal Drug Application. One condition imposed by the agency, however, is that manufacturers make these products available to the public only through licensed veterinarians with whom the purchaser has a valid VCPR. This marketing restriction is designed to protect the safety and well-being of patients.
Dr. Burkholder explained. "Many so-called VMF products manipulate physiological processes to extreme limits that are not tolerated by all patients. Furthermore, these physiological manipulations, in and of themselves, may not constitute effective treatment without additional pharmaceutical products, or may exacerbate side effects from additional pharmaceutical products."
The veterinarian should also do periodic reassessments to ascertain that the patient has not exceeded its ability to tolerate such extreme limits, and is responding to the product as expected and desired.