Caprine tuberculosis eradication program: an immunohistochemical study

We studied the evolution of different forms of tuberculosis in herds which are periodically submitted to the comparative tuberculin intradermal reaction (CTID) test within the Caprine Tuberculosis Eradication Program in the Region of Murcia (Spain). In the study, 135 goats with tuberculosis from different herds were diagnosed by histopathological and immunocytochemical techniques. Most animals (58 of the 135) were in the primary complex of tuberculosis, with few or no acid-fast bacilli (AFB) and mycobacterial antigens. Generalized tuberculosis was present in 31 of the 135 animals, and the numbers of bacilli and positive immunocytochemical particles were higher than in animals with the primary complex. Postprimary phase was observed in 44 of the 135 animals, and the number of bacilli and positive immunocytochemical particles increased in proportion to the extent and gravity of the necrotic foci. Tuberculous pneumonia with a high number of bacilli was only observed in two goats. Extrapulmonary tuberculosis was present with lesions in the intestines (60/135), liver (80/135) and spleen (77/135). This study confirmed that the Caprine Tuberculosis Eradication Program is resulting in fewer animals with postprimary tuberculous processes, and a corresponding increase in the number of primary complex and generalized tuberculosis.