Vol. 12, Special Issue 6 (2023)

A six year old male German Shepherd dog was presented with the condition of emaciated, recumbent, dyspnoea, muffled heart and lung, nonproductive cough, and enlarged abdomen and the animal collapsed while examination. Post mortem examination revealed a large quantity of exudation in the thoracic and abdominal cavities. Multiple, exophytic, pedunculated, yellowish-red, soft to firm masses ranging from 2 mm to 8mm in diameter were attached to the pericardium, pleura, mediastinum, lungs, peritoneum, serosal surfaces of the stomach and intestines, mesentery, mesenteric lymph nodes, liver, and spleen. Histopathological examination revealed the arrangement of neoplastic cells in sheets predominantly epithelial components with fine stroma and the neoplastic cells were round to spherical in shape with vesicular nuclei, anisokaryosis, multiple nucleoli, and numerous mitotic figures confirming the case as malignant mesothelioma in the thoracic and abdominal cavity.