This study was designed to evaluate the pathogenesis of caprine pleuropneumonia (CPP) in the experimentally inoculated goats with Mycoplasma mycoides subspecies Capri (Mmc). For this purpose, 12 goats (Group B) were inoculated with bacterial isolates of Mmc while four goats were kept as untreated control (Group A). Clinical signs of the disease were recorded twice daily.  Two goats from group B were sacrificed on weekly basis to demonstrate gross pathological lesions in different organs. Tissue samples from lungs, trachea, liver, heart, kidney, spleen, and small intestines were preserved for histopathological studies. The lungs and lymph nodes were preserved to demonstrate the antigen in tissue by using immuno- histochemical technique. The disease was successfully reproduced in all infected goats with severe manifestation. The clinical signs and gross lesions of the disease were mild at the beginning and became severe at the third and fourth weeks and then progressed to moderate and chronic forms. The histopathological lesions characteristic of CPP were found in all the organs. Antigen of Mmc was detected in tissue sections of lungs and lymph nodes. In conclusion, the disease was efficiently reproduced in experimental animals that showed acute septicemic form with lethal outcome.

Key words: Contagious caprine, pleuropneumonia, Immunohistochemistry, Mycoplasma mycoides subspecies Capri, Pathology