Feed lots, dairies and feed mills sure like those antibiotic drugs for animals.

The Food and Drug Administration (FDA) charged four animal agriculture practitioners in warning letters sent out April 21-30 with abusing mostly antibacterial drugs.  Misuse of animal drugs may mean antibiotics are getting into the human food supply at levels higher than tolerated by FDA.

FDA warning letters went out to agricultural operations in Florida, Washington state, Illinois, and Nebraska.

The first two warning letters went out to dairies:  Mayo, FL-based Land Dairy Inc. and Rochester, WA-based Elma Dairy, LLC.  Both were subjected to recent FDA investigations.

FDA said Land Dairy sold a dairy cow with liver tissues containing 0.2 parts per million (ppm) of sulfamethazine.   FDA considers the presence of any amount of the sulfa-based antibiotic in the edible tissues to be adulterated within the meaning federal law.

“Our investigation also found you hold animals under conditions that are so inadequate that medicated animals bearing potentially harmful drug residues are likely to enter the food supply,” Emma R. Singleton, FDA’s Florida district director, wrote.

FDA is not happy with Land’s recording keeping and inventory systems and further said the dairy was using the sulfa drug in ways not provided for on its label.

On the opposite corner of the country, Elma Dairy sold a dairy cow in Washington State where tissue sampling discovered the presence of desfuroylceftiofur or DFC of 1.04 ppm in kidney tissue and 0.44 of sulfadimethoxine in liver tissue.

FDA’s tolerance level for DFC in any edible tissue is 0.4 ppm and 0.1 ppm for sulfadimethoxine.

“Our investigation found that you administered ceftiofur hydrochloride to a dairy cow without following the withdrawal period as stated in the approved labeling,” Charles Breen, FDA’s Seattle district director, wrote Elma.

The U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) conducts tissue sample tests after cows are slaughtered for human consumption.

Tissue from a beef heifer sold by the Martin Food Lot in Harrisburg, IL was subjected to those tests and was the presence of 38.855 ppm of sulfamethazine and 0.1781 ppm of flunixin were found, both in the liver tissue.  FDA’s tolerances for these drugs are 0.1 ppm of negligible residues of sulfamethazine in the uncooked edible tissues of cattle, and 0.125 ppm (or 125 parts per billion) of flunixin in the liver.

“We also found you adulterated the new animal drug flunixin,” wrote Scott J. MacIntire, FDA’s Chicago district director.  He said Martin did not use the drug as directed on the label and did so without the lawful order of a licensed veterinarian.

Finally, at Darr Feedlots Inc. in Cozad, NE, the drugs chlortetracycline and monensin were being used in an unapproved combination in medicated animal feed.  The first of the two drugs is used to control a single cell parasite.

FDA said when combined in cattle feed the two drugs are unsafe.