Federal regulatory officials are considering changes to the routine tests for drug residues in milk.
And leaders in food animal medicine said the federal review provides a good reminder for veterinarians to reassess their pharmaceutical use and that of their clients.
"In FDA's ongoing efforts to further improve the safety of the food supply, FDA is reviewing enhancements to its current residue monitoring programs," Laura Alvey, deputy director of communications for the Food and Drug Administration's Center for Veterinary Medicine, wrote in a message. She said the agency had no further comments about the review.
Dr. Paul Rapnicki, a clinical professor at the University of Minnesota College of Veterinary Medicine, had some relevant conversations with state regulators and industry members at the April meeting of the National Conference of Interstate Milk Shipments. He thinks the FDA is maintaining that drug residues found in meat are proof of misuse of FDA-approved drugs and that expanding milk testing could determine whether that misuse is also causing undetected milk residues.
"It is clear that the tissue residues being found in cull dairy cattle are a very real concern to the FDA," Dr. Rapnicki said. "I believe that it is very likely that the FDA will pursue testing milk from farms that have known tissue violations.
"They appear to be very focused on what are termed 'repeat violators.'"
States and industry, in cooperation with the FDA, monitor milk predominantly for residues of beta-lactam antimicrobials and refuse loads that test positive, Alvey said. The Department of Agriculture tests meat and poultry for a variety of drug residues and reports its findings to the FDA.
Dr. M. Gatz Riddell, executive vice president of the American Association of Bovine Practitioners, said FDA-CVM officials have expressed concerns that inspections of dairy farms indicated cattle were receiving antimicrobials other than beta-lactam drugs. Residues of the other antimicrobials could escape detection through routine screening, and Dr. Riddell thinks the CVM intends to collect samples and check for a wider range of antimicrobial residues.
Dr. Riddell said milk producers could face financial and punitive actions from the FDA if their milk were to test positive for antimicrobial residues, while veterinarians and their records could face FDA scrutiny if residues were found in milk originating from their clients or producers who bought antimicrobials from them.
"In today's economic climate, many dairies would find that a very short time off-market—not being able to sell their milk—might result in economic disaster," Dr. Riddell said. He later added that, "For veterinarians with a solid veterinarian-client-patient relationship—who have taken the high road on this issue and gone the extra mile to ensure judicious antimicrobial use—this should not be an issue."
The AVMA Guidelines for Judicious Therapeutic Use of Antimicrobials are available here.
The AVMA has also produced a guide on extralabel drug use through the Animal Medicinal Drug Use Clarification Act, and that guide is also available here, which includes an extralabel drug use algorithm.