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Good, Bad News In FDA’s Survey On Drug Residues In Milk
No doubt about it, there was more good news than bad news in the survey on drug residues in milk that was released late last week by the US Food and Drug Administration. Still, there were some bothersome findings that indicate that the issue of drug residues in milk remains a problem for the dairy industry.
As reported on our front page last week, more than 99 percent of the milk samples in a 2012 survey involving the testing of almost 2,000 dairy farms for drug residues in milk were free of drug residues of concern.
How significant is that? Well, as noted in this space back on December 19, 2014 (“Drug Residues In Milk: 25 Years Later”), back on December 29, 1989, the front page of the Wall Street Journal carried a story with the following headline: “Milk Is Found Tainted With a Range of Drugs Farmers Give Cattle.”
That 1989 WSJ story detailed the findings of two separate surveys of fluid milk. Of 20 off-the-shelf samples purchased by the Center for Science in the Public Interest, 20 percent were found to be tainted with sulfa drugs, including sulfamethazine. And in the Wall Street Journal’s tests, involving 50 retail samples collected in 10 cities, 38 percent were found to be contaminated with sulfamethazine, other sulfa drugs or antibiotics.
So any survey in which more than 99 percent of the samples are free of drug residues of concern should be looked at as a sign of considerable progress in the dairy industry over the past 25 years.
Indeed, FDA itself put a pretty positive “spin” on this survey, issuing a “Constitute Update” with the following headline” “FDA’s Survey of Milk Finds Few Drug Residues.” And the agency noted that its survey findings “provide evidence that the nation’s milk safety system is effective in helping to prevent drug residues of concern in milk, even in those limited instances when medications are needed to maintain the health of dairy cattle.”
Despite these positives, there were at least a couple of problems unearthed in FDA’s survey. First, none of the confirmed drug residues identified in this survey are currently required to be routinely tested for under the Pasteurized Milk Ordinance for Grade A milk and milk products.
Last month, FDA released the “National Milk Drug Residue Data Base Fiscal Year 2014 Annual Report,” and, as reported on our front page on February 20th, a total of 703 milk samples out of 3,680,185 samples analyzed were positive for an animal drug residue. And of those positives, 684 (about 97 percent) tested positive for a beta lactam drug. Indeed, of the 4,008,662 total tests conducted, 3,652,160 were for beta lactams.
What did FDA’s survey find? Out of the 953 samples of the targeted group analyzed, the survey found six positives for Florfenicol, one positive for Tilmicosin, one positive for sulfamethazine, two positive for Tulathromycin, and one positive for gentamicin. All four positives in the non-targeted group were for Florfenicol.
The PMO requires that milk samples from every truckload of raw milk arriving at a dairy plant be tested for the presence of at least four of six specific beta-lactam drugs, but there are a number of other classes of drugs that are approved and may be used on dairy farms that are not currently required to be routinely tested for in raw milk under the PMO.
And, as noted earlier, none of the confirmed drug residues identified in FDA’s survey are required to be routinely tested for under the PMO.
The second problem with the survey findings is that none of the drugs found in the targeted or non-targeted groups are approved by FDA to be administered to lactating dairy cows. This means that the agency has not evaluated the use of these drugs in lactating dairy cattle, including whether milk from treated cows is safe for human consumption.
Two of the drugs detected in the survey (ciprofloxacin and sulfamethazine) are not currently approved for use in dairy cows and are prohibited from extralabel use. The presence of ciprofloxacin and sulfamethazine as confirmed drug residues in raw milk “suggests illegal extralabel use of a fluoroquinolone (enrofloxacin or ciprofloxacin) and sulfamethazine, respectively,” FDA said.
The other confirmed drug residues (Florfenicol, gentamicin, Tilmicosin, Tulathromycin) are not prohibited from extralabel use in dairy cows; however, the presence of these confirmed drug residues “is illegal and violates the conditions for legal extralabel drug use,” FDA stated.
Yet another problem with this survey is that it was conducted to determine whether dairy farms with previous tissue residue violations have more drug residues in raw milk than other dairy farms. FDA’s Center for Veterinary Medicine had announced the survey back in November of 2010.
Thus far in 2015, FDA has sent “Warning Letters” to several farms regarding tissue residue violations in animals offered for sale for slaughter. At least a couple of these animals were dairy cows, which would appear to indicate that the problem that prompted FDA to undertake this survey in the first place is still with us today.
One final problem with FDA’s survey is that it concerned antibiotic residues. The issue of antibiotic use in livestock has been garnering considerable attention lately, none of it good, so any survey finding of even a very small percentage of residues in milk presents the possibility of negative publicity for the dairy industry.
FDA’s survey contained more good news than bad news, but the bad news indicates there’s still room for improvement in the area of drug residues in milk. DG
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