Intoxicação espontânea por Senna obtusifolia em bovinos no Pantanal Sul-Mato-Grossense

Abstract

Pesq. Vet. Bras. 34(2):147-152, fevereiro 2014 147 RESUMO.-Descreve-se um surto de intoxicação por Senna obtusifolia em bovinos no estado de Mato Grosso do Sul, na região do Pantanal. Em um lote de 313 novilhas, 165 adoeceram e morreram (coeficientes de morbidade de 52,7% e de letalidade de 100%). Os bovinos permaneceram no piquete infestado pela planta por 37 dias. Os sinais clíni-cos consistiram em relutância em movimentar-se, andar trôpego (incoordenação), decúbito esternal permanente, diminuição do tônus de língua, estado comportamental em alerta, mioglobinúria caracterizada por urina castanho-escuro e fezes ressecadas com ou sem muco (ocasionalmente diarreicas com estrias de sangue). As principais alterações macroscópicas observadas nos 12 bovinos necropsiados estavam nos músculos esqueléticos dos membros pélvi-cos e foram caracterizadas por graus variáveis de palidez nos grupos musculares. Histologicamente, a lesão mais relevante encontrada foi degeneração e necrose segmentar multifocal nos músculos estriados esqueléticos (miopatia degenerativa tóxica multifocal polifásica). O diagnóstico da intoxicação baseou-se na epidemiologia (massa de forragem e de planta tóxica, análise da lotação do piquete e análise da precipitação pluviométrica), no quadro clínico dos animais e nos achados de necropsia e histopatologia. Senna sp. poisoning in livestock has been reported in several occasions in Brazil usually from southern Brazil and involving S. occidentalis as the culprit. The objective of this study is to report the occurrence of an outbreak of S. obtusifolia poisoning in cattle in the Pantanal Region of Mato Grosso do Sul, Brazil. In a herd of 313 heifers, 165 were affected and died (morbidity rate of 52.7% and lethality rate of 100%). The 313 heifers remained in the paddock infested by S. obtusifolia for 37 days. Clinical signs consisted of reluctance to move, incoordination, permanent sternal recumbency, decrease in the tonus of the tongue, alertness, myoglobinuria characterized by dark brown urine, and dry stools with or without mucus; or occasionally diarrhea with streaks of blood. The main gross findings in 12 necropsied cattle were in the skeletal muscles of the hind limbs, and were characterized by varying degrees of paleness of muscle groups. Histologically, the most relevant lesion was segmental multifocal degeneration and necrosis in striated skeletal muscles (multifocal lypolyphasic toxic degenerative myopathy). The epidemiological, clinical and pathological data allowed to conclude for the diagnosis of poisoning by S. obtusifolia in this outbreak. Intoxicação espontânea por

Poisoning by Senna obtusifolia in sheep

“…The shortage of forage was due to a high stocking rate (53 sheep and goats in an area of 1.5 hectare during 40 days) at the start of the dry season. These epidemiologic conditions are similar to those reported in outbreaks of S. obtusifolia poisoning in cattle (Henson et al 1965, Queiroz et al 2012, Carvalho et al 2014, Furlan et al 2014. Senna obtusifolia is a common weed in Northeastern Brazil; however, the poisoning has not been reported previously in ruminants in this region.…”

“…In the present outbreak, the clinical signs and pathology in sheep were similar to that observed in poisoning by S. obtusifolia and S. occidentalis in cattle, characterized by segmental degeneration and necrosis in striated muscles accompanied by high CK serum activity, myoglobinuria in most cases, and different degrees of liver lesions (Carvalho et al 2014, Furlan et al 2014. In previous experiments with small ruminants, it was not demonstrated that Senna spp.…”

“…The genus Senna (Leguminoseae Caesalpinioideae) is constituted by nearly 300 species with a circumtropical distribution (Souza & Bortoluzzi 2012). Poisoning by Senna obtusifolia in cattle was reported as a cause of segmental muscle degeneration and necrosis in United States of America (Henson et al 1965, Nicholson et al 1977, McCormack & Neisler 1980 and southern and central-western Brazil (Froehlich 2010, Queiroz et al 2012, Carvalho et al 2014, Furlan et al 2014. Poisoning by Senna occidentalis seeds or leaves had been reported in horses (Oliveira-Filho et al 2013) and pigs (Martins et al 1986) in southern Brazil, and cattle from Texas (Henson et al 1965, Pierce & O'Hara 1967 and southern Brazil (Barros et al 1990, 1999, Barth et al 1994, Carmo et al 2011.…”

Economic impact of an outbreak of botulism in a cattle feedlot

“…Diseases affecting the musculoskeletal system such as poisoning by plants of the genus Senna sp. (Carvalho et al 2014), ionophores antibiotics (Nogueira et al 2009), and hepatic encephalopathy stemming from intoxication by Crotalaria sp. (Anjos et al 2010), should also be considered among the differential diagnosis.…”

Botulism in ruminants in Brazil

“…Other differential diagnoses in cattle include bovine herpesvirus 5 encephalitis; listeriosis; toxicosis caused by ticks; polioencephalomalacia; hypocalcemia; hypomagnesemia; intoxications by lead, sodium chloride, organophosphates and chlorinated hydrocarbons; ingestion of mycotoxins produced by Aspergillus clavatus (known as the barley fungus); and ingestion of plants from genus Senna spp. (LOBATO et al, 2007;ANNIBALLI et al, 2013;CARVALHO et al, 2014).…”