Abstract
ABSTRACT. Martini-Santos B.J., Peixoto T. da C., Galvão A., Prado J.S., Aragão A.P. & Benevides M.L.C. de S. [Outbreak of acute intoxication by Pteridium arachnoideum (Kaulf.) in cattle]. Surto de intoxicação aguda por Pteridium arachnoideum (Kaulf.) em bovinos. Revista Brasileira de Medicina Veterinária, 32(2):92-96, 2010. Curso de Pós-Graduação em Medicina Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, BR 465, Km 7, Seropédica, RJ 23890-000, Brasil. Email: brunojmartini@hotmail.com Pteridium arachnoideum is considered one of the most important poisoning plants. In natural conditions can determine different clinical and pathological picture in several animal species. The acute by P. arachnoideum is characterized by a haemorrhagic syndrome, which causes death in about 12 to 72 hours. In the Serra da Mantiqueira, several major producers reported losses related to ingestion of the plant by the herd. In July 2008, was the death of 12 of the 15 cattle from a property free of the plant that had been placed in a pasture invaded by the fern in the city of Visconde de Mauá, RJ, Brazil. In the property during the visit, it was found that six animals demonstrated compatible symptoms with acute poisoning by the plant. At necropsy there were bleeding injuries in various organs and tissues of various shapes and intensities, and additionally hemopericardium. At histopathology showed marked rarefaction of hematopoietic tissue from bone marrow. Kidney there was hemorrhagic infarction with presence of bacterial colonies. The analyses carried out in hematologic samples revealed anemia, leukopenia and thrombocytopenia. During the inspection of grassland was verified the presence of the fern. The poor quality of pasture coupled with the intense invasion of the plant determined the occurrence of the outbreak. The diagnosis of acute poisoning by P. arachnoideum was based on epidemiological data in clinical pathology, the clinicalpathological and characteristics of macro and microscopic lesions observed.