Monensin poisoning in sheep in Uruguay

Abstract

Monensin is an antibiotic widely used in domestic animals. The aim of this paper is to describe three  monensin poisoning outbreaks in sheep, occurred in 2015 and 2016, in the eastern region of Uruguay. The main clinical symptoms were anorexia, rigidity, hindlimb paresis, and finally lying sack. At necropsy the main findings were generalized subcutaneous edema, hydrothorax, hydroperitoneum and  hydropericardium. In one case the urine had a reddish color. The hindlimb muscle masses showed pallor in all cases, while paleness in the heart muscle was observed in one case. The main histological lesions were degeneration and necrosis of skeletal and cardiac muscle. It is concluded that monensin poisoning in sheep occurs by the use of rations or salts formulated for cattle and by errors in commercial ration processing plants.