Ohio and Indiana dairy farms were warned earlier this month about selling animals for slaughter that were adulterated by the misuse of antibiotics.

Some experts blame the misuse of animal antibiotics for making some common antibiotics less effective in human medicine.

The first to receive a warning letter from the U.S. Food and Drug Administration was Troyer Farms in East Laotto, IN. The June 4 letter notified owner Timothy A. Troyer “of the violations of the Federal Food, Drug and Cosmetic Act that we found during our investigation of your operation.”

FDA inspected the Indiana dairy operation last March 9 and 10, finding a dairy cow sold on Aug. 11, 2009 for slaughter was adulterated. The animal drugs flunixin and gentamicin were found, respectively, in the liver tissue and kidney tissues of the dairy cow at unacceptable levels.

FDA has established a tolerance level for the non-steroidal anti-inflammatory drug, flunixin, of 0.125 parts per million (ppm), and the Troyer Farms cow had 1.0512 ppm in the liver tissue. There is no tolerance level for gentamicin, an antibiotic. It residue was found in the cow’s liver.

“The presence of these drugs in edible tissues from this animal in these amounts causes the food to be adulterated…” FDA wrote.

The U.S. Department of Agriculture’s Food Safety & Inspection Service (FSIS) tested the tissue samples.

FDA faulted the dairy for the holding medicated animals in conditions where harmful drug residues “are likely to enter the food supply.”

Poor record keeping and not following label directions for use of the animal drugs are adding to the problem, and not operating under lawful orders of a licensed veterinarian were cited as problems.

A Fredericksburg, Ohio dairy received the other recent warning letter. The June 10 notice to Clearview Farms concerned misuse of the neomycin, another antibiotic.

FDA’s investigation into the Ohio dairy last Jan. 11 and 13 focused on an Aug. 19, 2009 sale of a diary cow that was going to be turned into beefsteak.

The FSIS tests on tissues from the animal showed the presence of neomycin in the kidney at 7.34 parts per million (ppm). FDA has established a tolerance for residues of neomycin in the uncooked edible tissue of cattle at 7.2 ppm.

“Our investigation also found that you hold animals under conditions that are so inadequate that medicated animals bearing potentially harmful drug residues are likely to enter the food supply, ” the FDA warning letter said.

Other animal drug abuse by the dairy also concerns FDA.

“Our investigation also found that you caused the drug, Draxxin (Tulathromycin) Injectable Solution, NADA 141-244, to be unsafe within the meaning of section 512(a)(4) of the Act, 21 U.S.C. 360b(a)(4), because the drug was used in a manner that did not conform with its approved uses or the regulations for Extralabel Drug Use in Animals, 21 C.F.R. Part 530,” the letter continued.”

The Ohio dairy was also accused of administering animal drugs without the supervision of a state licensed vet.

Both dairies were given 15 working days to respond to FDA’s notices about their alleged violations.

Editor’s Note: We corrected the definition of flunixin in this update after being advised by an alert and informed reader (see comments).