Right ventricular hypertrophy, right ventricular failure and ascites in broiler chickens caused by Amiodarone-induced...

Four groups of male broiler chicks were given different amounts of amiodarone in the diet (0.0, 0.1, 0.2, 0.4%) from day 1 for 42 days. Six broilers from each group were necropsied weekly, from day 21, and tissues were collected for light and electron microscopy. Amiodarone was toxic and restricted growth at all concentrations but caused severe mortality at only the 0.4% level. On macroscopic examination, nine of the broilers on 0.1% amiodarone, 20 of those on 0.2% and 19 of those on 0.4% showed right ventricular failure, right ventricular failure and ascites, or right ventricular hypertrophy. Histologically, phospholipidosis was present in many organs. Ultra-structurally, type II pneumocytes in the atria of the lung were swollen and contained a large number of lamellar bodies. The significant pulmonary lesions in affected chickens were phospholipidosis in the atria and a marked hypercellularity in the interstitial tissue and blood capillaries. Type I pneumocytes in air capillaries were frequently degenerative and type II pneumocytes had invaded the air capillaries.