Extended Withdrawal Needed to Avoid Penicillin G Residues
US - A minimum 51-day withdrawal is necessary if penicillin G is used in pigs destined for processing, according to the American Association of Swine Veterinarians (AASV).
The USDA’s Food Safety and Inspection Service (FSIS) recently validated its testing methodology to enable the identification of penicillin G procaine in edible tissues at processing, according to Dr Harry Snelson of the AASV. This has resulted in an increase in penicillin residue violations in cull sows. These violations raised the concern of pork producers and veterinarians because many of the violations occurred even though the producer was following the prescribed withdrawal period. The AASV, in collaboration with the National Pork Board (NPB) and the National Pork Producers Council (NPPC), has been working diligently with FSIS and the Food and Drug Administration (FDA) to try to understand what is causing this increase in penicillin violations.
Penicillin G procaine remains an effective treatment in cull sows. It is relatively inexpensive and can be purchased over the counter. It is most often administered intramuscularly at an extra-label dosage of 33,000IU per kg for three consecutive days. The Food Animal Residue Avoidance Databank (FARAD) recommends at least a 15-day withdrawal to allow the drug to clear the tissues prior to processing.