title: Monensin toxicosis in water buffaloes (Bubalus bubalis).
abstract: 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. Histopathological changes 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.
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine, Federal University of Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves 9090, 91540-000 Porto Alegre, RS, Brazil.
authors.forename: Daniela Bernadete
authors.initials: DB
authors.lastname: Rozza
authors.forename: Ingrid
authors.initials: I
authors.lastname: Vervuert
authors.forename: Josef
authors.initials: J
authors.lastname: Kamphues
authors.forename: Cláudio Estêvão Farias
authors.initials: CE
authors.lastname: da Cruz
authors.forename: David
authors.initials: D
authors.lastname: Driemeier
mesh_terms: D000818:Animals; D000855:Anorexia / Q000139:chemically induced / Q000473:pathology / Q000662:veterinary*; D002020:Buffaloes; D006651:Histocytochemistry / Q000662:veterinary; D007476:Ionophores / Q000506:poisoning*; D008985:Monensin / Q000506:poisoning*; D009135:Muscular Diseases / Q000139:chemically induced / Q000473:pathology / Q000662:veterinary*
chemical_list: D007476:Ionophores; D008985:Monensin