Miliary Bovine Farcy Experimentally Induced in a Zebu Calf

Abstract

A 2-year-old Zebu calf was inoculated intravenously with a suspension of Mycobacterium farcinogenes [I] (formerly Nocardia farcinica) isolated from a cow in the Nuba Mountain region of the Sudan. The suspension was subcultured several times on Lowenstein-Jensen medium and was prepared by washing the growth of about six colonies into a McCartney bottle with 10 milliliters of normal saline. The calf had no rise in temperature nor other clinical signs until 60 days after inoculation when it started to lose condition. On the 80th day it began to have respiratory distress and abdominal respiration. It died the 84th day. Lesions were confined to the lungs which were studded with evenly distributed nodules about 2 millimeters in diameter (fig. I). No lymph nodes were affected. The caseous material in the nodules was white-grey, difficult to emulsify in water and had no calcium deposits. Smears stained with modified Ziehl-Neelsen had acidfast filamentous organisms indistinguishable microscopically from M. farcinogenes. The organism was recovered on Lowenstein-Jensen medium after 10 days incubation at 37'C. Colonies were large, 3 to 4 millimeters in diameter, with convoluted surface. We were unable to trace a similar finding of miliary farcy in either natural or experimentally infected bovine animals.