Q Fever Studies in Southern California: XII. Aureomycin Treatment of Dairy Cattle Naturally Infected with Coxiella burnetii

Abstract

39 of 40 dairy cows selected for the 2 treatment studies on the basis of high serum antibody levels were found to be shedding C. burnetii in their milk. With the dosages of aureomycin used, no apparent decrease in antibodies occurred during or for a 9 to 11-month observation period following either intramammary or intraven. treatment. Aureomycin admn. by intramammary infusion (100 mg. twice a day) for 5 days did not result in the clearing of C. burnetii from the milk of any of 10 treated cows during an 11-day observation period. The treatment of cows by daily intraven. injn. of a total of 15 g. of aureomycin over a 5-day period failed to eliminate C. burnetii from the milk of 9 of 10 infected animals within 3 days, or from 5 of 7 cows tested 6 months later.