Intoxicação por Crotalaria retusa (Fabaceae) em Eqüídeos no semi-árido da Paraíba

Abstract

were observed in horses on 8 farms in the semiarid region of Paraíba and Ceará. C. retusa was found in all farms. The main clinical signs were characteristic of hepatic encephalopathy, with dullness or hyperexcitability, head pressing, compulsive walking or circling and, occasionally, violent uncontrollable galloping. Decreased cranial nerve reflexes, ataxia and weakness were also observed. Other clinical signs were anorexia, weight loss, photosensitization and jaundice. The clinical manifestation period varied from 4 to 40 days, but most horses had a previous history of weight loss. At necropsy the livers were hard, with irregular surface and white areas mixed with dark red areas and increased lobular pattern. Mild jaundice, ascitis, hydropericardium and hydrothorax were also observed. Edema and moderate congestion were seen in the lungs. Histologic changes of the liver were characterized by fibrosis, mainly periportal, megalocitosis and bile duct cell proliferation. Multifocal areas of centrilobular or midzonal hemorrhages were also observed. Centrilobular hemorrhagic necrosis was present in two horses. Alzheimer type II astrocytes were observed, isolated or in groups, mainly in the caudate nucleus and cortex in 4 horses. The poisoning was experimentally produced in 1 adult horse and 3 adult donkeys. The horse received daily 100 g of C. retusa seeds and died 52 days after the beginning of the experiment. The dried whole C. retusa was mixed with grass and given to the 3 experimental donkeys at daily doses of 10g/kg, 5g/kg and 2.5g/kg, respectively. The donkey treated with 5g per kg died 48 days after beginning of the experiment and the other two were sacrificed at 120 days. Clinical signs and pathology were similar to those observed in spontaneous cases, but Alhzeimer type II astrocytes were observed only in the donkey that died 48 days after the beginning of ingestion of the plant material. The concentration of monocrotaline in the whole plant given to the donkeys was 0.5%.INDEX TERMS: Poisonous plants, plant poisoning, Crotalaria retusa, Fabaceae, hepatic cirrhosis, horse, pirrolizidine alkaloids.

Doenças do sistema nervoso central de equídeos no semi-árido

“…A intoxicação por Crotalaria retusa descrita anteriormente (Nobre et al 2004) o tétano e a raiva são as doenças mais freqüentes. Em relação ao tétano os veterinários não têm dificuldades de diagnóstico, mas no caso da intoxicação por C. retusa o diagnóstico diferencial deve incluir, principalmente, as encefalites virais (raiva e encefalomielite viral equina).…”

“…Em relação ao tétano os veterinários não têm dificuldades de diagnóstico, mas no caso da intoxicação por C. retusa o diagnóstico diferencial deve incluir, principalmente, as encefalites virais (raiva e encefalomielite viral equina). No caso da raiva o diagnóstico diferencial pode ser feito pelo curso clínico geralmente mais prolongado na intoxicação por C. retusa, assim como pelos sinais ou alterações da bioquímica sanguínea sugestivas de insuficiência hepática (Nobre et al 2004). Em qualquer uma das duas doenças o diagnóstico laboratorial é simples e definitivo.…”

“…Seis do total de casos descritos ocorreram entre os anos de 2002 e 2003 e já foram descritos por Nobre et al (2004), por tanto os dados aqui apresentados serão referentes a 8 novos casos que estão representados no Quadro 1, com os respectivos dados epidemioló-gicos. Sete casos ocorreram em municípios da Paraíba e um no estado do Ceará.…”

Atividade farmacológica da monocrotalina isolada de plantas do gênero Crotalaria

“…Os sinais clínicos e graves foram os mesmo observados nos rebanhos de ovelhas no campo. Nobre et al (2004b) observaram os mesmos sinais clínicos em equinos e asininos que se intoxicaram ingerindo as sementes durante a alimentação. Além disso, a necropsia revelou astrócitos Alzheimer tipo II, isolados ou em grupos principalmente no núcleo caudato e córtex.…”

Duration of an induced resistance of sheep to acute poisoning by Crotalaria retusa seeds

“…In northeastern Brazil, spontaneous ingestion of Crotalaria retusa L. (Figure 1) has been diagnosed as a cause of chronic liver fi brosis and megalocytosis in horses (NOBRE et al, 2004b) and acute liver necrosis in sheep (NOBRE et al, 2005;RIET-CORREA et al, 2011). Recently it was demonstrated experimentally that sheep are susceptible to acute intoxication by monocrotaline (MCT)-containing C. retusa seeds and can be poisoned by a single oral dose of seeds equivalent to about 205mg MCT per kg of body weight (mg kg -1 ), but they develop a resistance to these acutely lethal oral doses after the daily continuous ingestion of non-toxic dose of seeds equivalent to about 136mg MCT kg -1 (ANJOS et al, 2010).…”