Blood serum and milk serum levels of sodium benzylpenicillin after intravenous regional antibiosis in surgery of the claw area in cattle

An intravenous regional antibiosis using 10 Mega I.U. Sodium-Benzylpenicillin was carried out during surgery in 14 dairy cows affected with spontaneous occurring digital diseases. Blood serum and milk serum levels were determined over a period of 48 hours by means of a micro agar diffusion method using Sarcina lutea Stamm BGA Berlin as a test germ. Even before opening of the rubber tourniquet, penicillin traces were detectable in the blood serum of 6 cows. Maximal concentrations ranging from 0.43 mcg/ml to 8.63 mcg/ml were determined after 45 minutes to 4 hours. 24 hours after intravenous regional antibiosis no levels above the limit of detectability were determined. Significant lower maximal concentrations were found in claw amputation cases as compared with claw preserving surgical interventions. Milk serum levels showed delayed and lower maximal concentrations, ranging between 2.09 and 0.09 mcg/ml. In 5 animals no positive levels were detected. After 48 hours, penicillin levels were below the limit of detectability in the milk of all examined animals.