PULMONARY-LESIONS IN THE EARLY PHASE OF C ONTAGIOUS BOVINE PLEUROPNEUMONIA (CBPP) - HISTOLOGICAL AND IMMUNOCYTOCHEMICAL FINDINGS

Recent pulmonary lesions at slaughter in bovines affected by Mycoplasm a mycoides during the years 1990-1993 in Northern Italy are reported. Several histologic and immunocytochemical examinations showed that: th e earliest lesions of CBPP are foci of desquamative bronchiolo-alveoli tis, the highest concentration of the antigen is found in the cytoplas m of desquamated alveolar macrophages. From our results, we can exclud e that CBPP begins with interstitial lesions as some authors have hypo thesized. On the contrary, the hypothesis, formulated at the beginning of the century, that CBPP begins with a desquamative bronchiolo-alveo litis seems to be more convincing. Our results give some help to const ruct a correct pathogenesis of the disease.