Monensin toxicosis in water buffaloes (Bubalus bubalis)

• Published in: Journal of veterinary diagnostic investigation 2006-09, Vol.18 (5), p.494-496
• Main Authors: Rozza, D.B, Vervuert, I, Kamphues, J, Cruz, C.E.F. da, Driemeier, D
• Format: Article
• Language: English
• Subjects: accidents; acute toxicity; Animals; Anorexia - chemically induced; Anorexia - pathology; Anorexia - veterinary; Buffaloes; dosage; feed additives; feed contamination; food animals; Histocytochemistry - veterinary; histopathology; Ionophores - poisoning; medicated feeds; monensin; Monensin - poisoning; mortality; Muscular Diseases - chemically induced; Muscular Diseases - pathology; Muscular Diseases - veterinary; pathogenicity; poisoning; signs and symptoms (animals and humans); species differences
• ISSN: 1040-6387; 1943-4936
• DOI: 10.1177/104063870601800515

Correspondence: 1 Corresponding Author: David Driemeier, Departamento de Patologia Clínica Veterinária Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves, n ° 9090, 91540-000 Porto Alegre RS, Brazil The consumption of monensin-containing feed resulted in deaths of water buffaloes from a feedlot in which cattle and buffaloes were kept together. The monensin formulation was recommended only for use in cattle. Anorexia, muscular weakness, dyspnea, and recumbency were the major clinical findings. The most significant gross lesions were focal pale areas in semitendinosus and semimembranosus muscles, in which segmental necrosis of myofibers was seen microscopically. To compare susceptibilities of species to monensin, 3 bovine calves and 3 buffalo calves were orally dosed. At 5, 7.5, and 10 mg/kg of monensin, only the buffaloes became ill and died. Clinical signs initiated 18–20 h postdosing and were comparable to those from field cases. Gross changes consisted of ascites, hydrothorax, hydropericardium, hepatomegaly, and focal pale areas in the myocardium and to a lesser degree in semitendinosus and semimembranosus muscles. Histopathologicalchanges also resembled those from the field cases, but were especially pronounced in the myocardial cells. The hypothesis that buffaloes could have a lower tolerance to monensin than cattle has been supported by experimental cases. Key Words: Buffaloes • degenerative myopathy • monensin tolerance • monensin toxicity