Kajian myelositomatosis pada ayam broiler sebagai imunosupresor

Abstract

Myelocytomatosis or myeloid leucosis (ML) is a kind of neoplastic disease caused by Avian leucosis virus subtype J (ALV–J) infection, which often found in chickens worldwide. Myelocytomatosis in chickens cause reduced productivity and increased mortality in flocks. The aim of this study was to make pathological assessment of ML occurred in a broiler farm. Increased mortality with breathing difficulty (dyspnoea) were noted in broiler flocks aging 7 and 14 days. Afterwards necropsy was performed and organs were sampled for histopathological examinations. All organs were embedded in paraffin, sectioned at 5 μm, and stained with hematoxylin and eosin (for morphology), periodic acid–Schiff for carbohydrates, and Masson trichrome for collagens. Histopathological findings of ML included scattered myeloid cells depositions in the interstitium and perivascular area of kidney, liver, lung, and heart. Additionally, high percentage (>70%) of myeloid cells were found in the bone marrow. In addition to ML in various organs, there were invasive granulomatous pneumonia comprises of poorly demarcated fibrous bands, and septate fungal hyphae which consistent with the morphology of Aspergillus spp. Myelocytomatosis were also detected in the breeder flocks aging 29 weeks, notably in liver and ovaries. These findings suggest that vertical ML transmission may cause immunosupression which lead to invasive granulomatous lesion. Invasive granulomatous pneumonia with ML has never been documented in poultry.