Immunizing effects of live Corynebacterium pseudotuberculosis in goats

Twenty goats ranging from 4 to 7 months of age were divided into two groups. Group 1 consisted of five goats inoculated intradermally with 4.0 × 10⁶ virulent Corynebacterium pseudotuberculosis. Group 2 consisted of fifteen goats vaccinated intradermally with a single dose of 20 × 10³ C. pseudotuberculosis. Twelve weeks later the goats in group 2 were reinoculated with 4.0 × 10⁶ virulent organisms. All goats from group 1 developed abscesses at the site of inoculation, in the draining lymph nodes, as well as in internal viscera and or lymph nodes. None of the goats in group 2 developed abscesses in their external lymph nodes or viscera but one goat had a small abscess in a single mesenteric lymph node and one goat in a retropharyngeal lymph node. Ten of the 15 goats from group 2 had small abscesses at the site of inoculation which developed after the challenge inoculation. It was concluded that small doses of live C. pseudotuberculosis stimulated an immune response capable of preventing the development of abscesses in the draining lymph node as well as protected against the development of internal abscesses.