USDA’s Food Safety Inspection Service (FSIS) has come out to report that several penicillin G violative residues have surfaced in culled sows brought to market.

Historically, the U.S. pork industry has experienced extremely low levels of antimicrobial residues detected at slaughter so this occurrence raises concerns regarding the timing of antimicrobial use in sows intended for processing, as well as FSIS’ testing methodology, the American Association of Swine Veterinarians said in a released statement.  

At this time, AASV, the National Pork Board and the National Pork Producers Council are working with FSIS to better understand the testing methodology that the agency uses. The groups will evaluate whether extended product withdrawal periods will be necessary to ensure compliance with the zero-tolerance-level the industry applies to penicillin. “We have also been in contact with one of the major penicillin manufacturers to inform them of FSIS’ recent findings and discuss any necessary changes to the withdrawal recommendations,” AASV said.  

Further, AASV is reminding its members to consult with producer clients to ensure that they are following appropriate withdrawal times for any and all antimicrobials used in swine that will be shipped to market, including cull sows and boars.

Specific to penicillin use, AASV reminds veterinarians and their clients of the following:

1)     Penicillin G is approved for use in swine only to treat erysipelas.

2)     The labeled dose rate for penicillin G is 3,000 units per pound of body weight (1 ml per 100 pounds of body weight).

3)     Any use for other indications or at a different dosage rate would be considered extra-label drug use and can only be done under the direction of a veterinarian as outlined in AMDUCA.

4)     Extra-label use also requires the application of an extended withdrawal period which may be difficult to achieve with cull animals.

5)     Long-acting pencillin (penicillin G benzathine) is not approved for use in swine and, thus, any use would be considered extra-label.

The Food and Drug Administration approved a 7-day withdrawal period for penicillin G, treated at the labeled dosage. However, AASV and NPB have historically recommended an extended withdrawal period of at least 14 days in order to meet export requirements.

“Also note that the recommended voluntary withdrawal period for long-acting penicillin is 50 days to meet export requirements,” AASV points out. A database of recommended withdrawal periods for export can be found on the NPB website. Pork.org

Source: AASV