[Pulmonary changes in the early phase of contagious bovine pleuropneumonia. Histologic and immunohistochemical aspects].

Recent pulmonary lesions at slaughter in bovines affected by Mycoplasma mycoides during the years 1990-1993 in Northern Italy are reported. Several histologic and immunocytochemical examinations showed that: the earliest lesions of CBPP are foci of desquamative bronchiolo-alveolitis, the highest concentration of the antigen is found in the cytoplasm of desquamated alveolar macrophages. From our results, we can exclude that CBPP begins with interstitial lesions as some authors have hypothesized. On the contrary, the hypothesis, formulated at the beginning of the century, that CBPP begins with a desquamative bronchiolo-alveolitis seems to be more convincing. Our results give some help to construct a correct pathogenesis of the disease.