Corynebacterium pseudotuberculosis infection in goats. VII. Clinical, pathological, serological and hematological changes after subcutaneous inoculation of the organism.

Six castrated male kids from 2 herds free from caseous lymphadenitis, were inoculated subcutaneously with about 1 million colony forming units of a Corynebacterium pseudotuberculosis strain isolated from goat. The animals exhibited a febrile response and marked inflammatory reaction at the inoculation site during the first days after infection. Post mortem examination carried out 2 months after inoculation revealed abscesses in the regional lymph node (Inn. subiliaci) of all animals, in 3 of which lesions also appeared in other lymph nodes. The antibody titre (mean value) in the bacterial agglutination test peaked during the first 2 weeks following inoculation, while the titre in the hemolysis inhibition test began to rise from 2–3 weeks after the infection and continued to increase during the rest of the investigation period (9 weeks after inoculation). Hemoglobin and hematocrit levels decreased significantly after inoculation, and remained below the preinfection levels for 2 weeks. A significant leucocytosis was also seen during the same period. The present investigation indicates that subcutaneous inoculation with C. pseudotuberculosis might be a suitable challenge system to study the efficacy of vaccines against caseous lymphadenitis in goats.