FDA WARNING_LETTER - Shrock, John E. - February 22, 2008

On February 20 and 22, 2008, the FDA investigated John E. Shrock's dairy operation in Middlefield, Ohio. The investigation revealed that on or about December 3, 2007, Shrock sold a bob veal calf for slaughter. USDA/FSIS analysis of tissue samples from this calf, slaughtered on December 4, 2007, found 19.94 ppm of sulfamethazine in the liver and 22.94 ppm in the muscle tissue. This significantly exceeds the FDA tolerance of 0.1 ppm for sulfamethazine residues in cattle edible tissues (21 C.F.R. 556.670).

The FDA determined that Shrock adulterated the new animal drug sulfamethazine by not using it according to its approved labeling, constituting an extralabel use (21 C.F.R. 530.3(a)). This extralabel use was not under the supervision of a licensed veterinarian within a valid veterinarian/client/patient relationship, violating 21 C.F.R. 530.11(a). Furthermore, this extralabel use resulted in an illegal drug residue, violating 21 C.F.R. 530.11(d). Consequently, the drug was deemed unsafe under section 512(a) of the Act (21 U