ABSTRACT
A 16-month-old Holstein heifer with a history of anorexia and respiratory distress was referred to the Veterinary Research and Teaching Hospital of Tehran University. Heart and lung sounds were inaudible on the left side but greatly increased on the right side. On electrocardiography [ECG], decreased amplitudes of ECG parameters were observed. Ultrasonography results revealed a pleural effusion with fibrin deposition. After the removal of 30 liters of pleural fluid, the amplitudes of the P, QRS, and T complexes increased markedly, and heart and lung sounds on the left side gradually increased. Archanobacterium pyogenes was isolated from bacteriological cultures of the pleural fluid. According to the clinical and paraclihical findings, cardiac displacement due to pleural effusion was diagnosed