Two outbreaks of Senecio madagascariensis poisoning in cattle occurred in October 2013 in southern Brazil. Morbidity rate ranged were 3.2% and 6.1%, and lethality rate was 100%. A third case of poisoning occurred on a property in which out of 54 cattle one died with clinical signs of intoxication. In all cases, the cattle were in areas highly infested by S. madagascariensis that was in bloom. The clinical signs were diarrhea, tenesmus, opisthotonus, and progressive weight loss. Death occurred between 10 and 15 days after the onset of clinical signs. At necropsy, lesions were edema in the mesentery, in the wall of the rumen and abomasum, and in the walls of the gall bladder; the liver was firm with marbled aspect. Histologically, the liver had proliferation of fibrous connective tissue, especially in portal areas, hepatomegalocytosis, and bile duct hyperplasia. The observation of large number of S. madagascariensis in several farms in the counties of Arroio Grande, Pedro Osório and Capão do Leão reinforces that this plant is in the process of adaptation and dissemination in this region and that other outbreaks may occur in coming years. The cases reported here apparently resulted from the consumption of the plant during the fall/winter of 2013, when it was in bloom. The quantification of alkaloids in S. madagascariensis revealed the presence of 500µg/g and 4000µg/g of pyrrolizidine alkaloids in the dry plant from two properties. It is believed that the large amount of the plant in the areas where the animals were and the amount of pyrrolizidine alkaloids found were factors that contributed to the occurrence of outbreaks.
Poisonous plants; Senecio madagascariensis; Asteraceae; hepatotoxic plants; seneciosis; plant poisoning; cattle
