EXPERIMENTAL PULMONARY ASPERGILLOSIS IN CALVES WITH APPLICATION OF BRONCHOSCOPIC TECHNIQUES

Pulmonary aspergillosis was induced in 2 groups of calves by intrabron chial inoculation of Aspergillus fumigatus spores and mixture of spore s and mycelia @ 20 mi (3.4 x 10(8) spores/ml in both inocula) using br onchoscope without anaesthesia. Bronchoscopic procedures (bronchoalveo lar lavage, brush cytology and lung biopsy) were employed to evaluate their diagnostic applicability in calves. The biopsy specimens evinced polymorphonuclear cells initially followed by mononuclear and epithel ioid cell predominance in spores-treated group 2 while mixed cellular reaction followed by lymphocytic infiltration was the main feature in spores+mycelia-treated group 3. On necropsy, progressive severity of l esions was noticed grossly at various stages in both the groups except ing in 3 surviving calves of group 3. Microscopically, haemorrhagic le sions at 12 DPI, mononuclear aggregates at 17 DPI, and granulomatous d iscrete lesions from 19 to 39 DPI were observed in group 2. In group 3 mixed reactions at 8 DPI with development of granulomatous lesions at 12 and 16 DPI were evident. Branched fungal hyphae were demonstrable in granulomas in both the infected groups. The disease course was prol onged in spores-treated group but was shorter with early culmination i nto chronicity of the lesions in spores+mycelia-treated group. Broncho scopic techniques were considered helpful in the early diagnosis of pu lmonary aspergillosis in calves.