The federal Food and Drug Administration (FDA) has issued a warning letter over the misuse of animal drugs at Vander Schaaf Dairy #2, located in Escalon, CA.

According to FDA, the dairy offered an animal for sale for slaughter as food that was adulterated.  A dairy cow sold by Vander Schaaf last April 9 was slaughtered the next day and USDA’s Food Safety and Inspection Service (FSIS) subjected the animal to tissue sampling.

FSIS analysis of the samples turned up the presence of the sulfonamide antibiotic known as Sulfadimethoxine at a level of 7.068 parts per million (ppm) in the liver tissue.  “FDA has established a tolerance of 0.1 ppm for residues of Sulfadimethoxine in the edible tissues of cattle..,” FDA’s Jan. 10 warning letter to Vander Schaaf says.

FDA said the presence of the drug at levels exceeding the tolerance amount means the animal is adulterated as food.

FDA clearly is not happy with the operation of the California dairy, including its record-keeping. In addition to Sulfadimethoxine, the dairy’s use of Penicillin G Procaine and Ceftiofur, another antibiotic, was questioned by FDA.

FDA said the penicillin and ceftiofur, originally provided by Pfizer in the late 1980s and marketed as Excede, were not being used as directed by the label. Only a veterinarian with a valid reason can use the antibiotic drugs for reasons not provided for on the label.

Vander Schaaf stands accused of using Sulfadimethoxine without following the dosing instructions on the label.

Some strains of E. coli have formed a resistance to ceftiofur. While most frequently used in veterinary medicine to treat respiratory, urinary tract, enteric, and soft tissue infections, Sulfadimethoxine is also used for humans in some parts of the world, including Russia.  Several Russian pharmaceutical companies manufacture it for over-the-counter use.