After a milk sampling survey was conducted at nearly 2,000 dairy farms, the U.S. Food and Drug Administration (FDA) has confirmed that the overwhelming majority of America’s milk supply is indeed safe, even in cases that require medication to maintain the health of dairy cattle.

To keep cattle healthy, they are sometimes treated with a variety of drugs. One of the after effects is that residues from those drugs might be present in milk (or meat). Milk found to contain illegal drug residues cannot be sold for human consumption.

In this latest round of tests, 99 percent of milk samples tested were found to have no presence of drug residues.

The purpose of the study was to take a deeper look at whether or not dairy farms with previous drug residue violations were more likely to show evidence of such residues in the milk they produced. Two groups were studied––a “targeted” list of farms that had a history of past residue violations, along with a control group. Both groups displayed a very low level of drug residue occurrences.

The small volume of residues found involved drugs that are not included in routine milk safety testing. As a result, the FDA plans to try modifying the test to include testing for those drugs currently unaccounted for during sampling. Besides urging greater diversity in their testing of drugs, the agency will also help to educate dairy producers on best practices to avoid drug residues in both cattle tissues and milk.