Intoxicação em bovinos pelo cogumelo Ramaria flavo-brunnescens

A study of two incidents of the disease known in Rio Grande do Sul, Brazil, as “mal do eucalipto”, and a study with ten bovines dosed with the murshroom Ramaria flavo-brunnescens are reported. The administration of a minimum dose of 5 g of mushroom per kg of animal body weight is sufficient to produce symptoms of the disease. A minimum dose of 20 g/kg daily for 18 days produces death, and excessively high doses (36 g/kg) may cause death with a single administration. The symptoms observed in the experimental animals included sialorrhea, loss of body weight, loss of hair at the tip of the tail, and atrophy of the tongue papillae. Ulcerations of the tongue and esophagus were the most predominant lesions observed in autopsied animals. Microscopic examination showed these to be degenerative lesions, necrosis and inflammatory infiltration of the mucous membrane, hemorrhages and slight inflammatory reaction in the central nervous system. Loosening of hooves and horns, hemorrhages in the anterior chamber of the eye, and blindness were additional symptoms observed in animals which had contracted the disease naturally. By comparing results of the experiments with the symptoms of those animals found to be suffering from the disease naturally, it can be concluded that the so-called "mal do eucalipto" is produced by ingestion of R. flavo-brunnescens.São relatados um estudo de dois casos naturais da doença conhecida no Rio Grande do Sul como "mal do eucalipto" e um estudo experimental com o cogumelo Ramaria flavo-brunnescens em 10 bovinos. Dos experimentos concluiu-se que são necessárias as doses mínimas diárias de aproximadamente 5 g do cogumelo por kg de peso do animal durante 5 dias, para produzir sintomas da doença, e de 20 g/kg durante 18 dias, para provocar a morte, e, que uma única administração de dose excessivamente alta (36 g/kg) pode levar à morte. Os sintomas observados nos casos experimentais foram sialorréia, emagrecimento, queda dos pêlos da extremidade da cauda e atrofia das papilas linguais. As lesões macroscópicas mais importantes, nos animais necropsiados, foram ulcerações na língua e no esôfago. Microscopicamente foram vistas lesões degenerativas, necrose e infiltrado inflamatório nas mucosas, hemorragias e discreta reação inflamatória no sistema nervoso central. Nos casos naturais da doença foram observados, ainda, o afrouxamento dos cascos e chifres, hemorragias na câmara anterior do olho e cegueira. Pela comparação dos experimentos com os casos espontâneos, concluiu-se que o chamado "mal do eucalipto" é produzido pela ingestão do cogumelo R. flavo-brunnescens

Ultrastructural changes in the myocardium in the experimental poisoning of rabbits by calcinogenic plant Solanum malacoxylon

Six rabbits of both sexes, 3-months old, were given via gastric tube an aqueous extract of the plant Solanum malacoxylon, equivalent to 100 mg of dried leaves per kg of body weight. Two rabbits (controls) did not receive the extract and were killed at the end of the experiment. All others rabbits were killed at 48,72 and 120 hours after extract administration. Fragments of myocardium were sampled and processed for both light and electron microscopy. Most significant gross changes observed were whitish streaks in the myocardium, especially in the right atrium. On light microscopic examination, groups of muscle cells had swollen sarcoplasms with loss of striations, slight basophila and eventual sarcoplasmic vacuolizations. These groups of cells were usually surrounded by macrophages, mesenchymal cells and few neutrophils admixed with necrotic debris. There was a delicate granular basophilic material in the interstitium. Von Kossa staining revealed, at these sites, calcium deposits within the sarcoplasm of cardiac myocytes in the interstitium and,occasionally, around apparently non damaged myocytes. There was mineralization of the medial tunic of coronary arteries. On the EMexamination the following changes were observed: activation of cardiac myocytes and interstitial cells, calcium deposits in the interstitiumand in the sarcosplasm of cardiac myocytes, as well as in the cytoplasm of interstitial cells. In late stages there was necrosis of cardiac myocytes, with mineralization and cytolisis. Few neutrophils and macrophages, with phagocytized mineral necrotic debris were also observed at these sites. The morphological aspect of the myocardium suggests that necrosis and calcification result from the direct action of the 1,25(OH)2D3 present in the plant on the myocardial cells. No changes in the myocardium of control rabbits were found.Seis coelhos com cerca de três meses, de ambos os sexos, receberam via sonda gástrica, extrato aquoso de Solanum malacoxylon equivalante a 100 mg de folhas dessecadas por kg de peso vivo. Dois animais não receberam o extrato e serviram como testemunhas, sendo sacrificados ao final do experimento. Entre 48, 72 e 120 horas após o início do experimento, todos os outros coelhos foram sacrificados e fragmentos do miocárdio foram processados para microscopia óptica e eletrônica. As alterações macroscópicas mais importantes foram estrias esbranquiçadas no miocárdio, particularmente no átrio esquerdo. Em microscopia óptica, grupos de células musculares mostravam sarcoplasma tumefeito, com perda das estriações, discreta basofilia e eventualmente vacuolizaçõesdo sarcoplasma. Estas células geralmente estavam rodeadas por macrófagos, células mesenquimais e alguns polimorfonucleares neutrófilos de permeio com material necrótico. No interstício foi evidenciado material basofílico finamente granular. A reação de vonKossa nestes locais revelou depósitos de cálcio no sarcoplasma dos míócitos, no interstício e, eventualmente, ao redor de células musculares aparentemente não lesadas. Os vasos coronários exibiam mineralização da média. Na ultra-estrutura foram observadas: ativação dos cardiomiócitos e das células intersticiais, deposição do cálcio no interstício e no sarcoplasma das células musculares cardíacas e no citoplasma de células intersticiais. Em fases mais avançadas observou-se nécrosé dos cardiomiócitos, com mineralização das células e lise celular. Alguns polimorfonucleares neutrófilos e macrófagos fagocitando material necrótico mineralizado são também vistos nestes locais. O aspecto morfológico do miocárdio surgere que as lesões de nécrosé e calcificação são o resultado da ação direta do 1,25(OH)2D3 contido na planta sobre as células do miocárdio. Os animais testemunhas não exibiram alterações no miocárdio

Hepatic Encephalopathy Secondary to Chronic Liver Lesions Caused by Crotalaria incana in a Bovine

Background: Crotalaria spp. Poisoning induces liver or pulmonary disease. C. mucronata, C. juncea, C. spectabilis, and C. retusa are the Crotalaria spp. inducing spontaneous intoxication in livestock in Brazil. C. mucronata and C. juncea are associated with interstitial pneumonia, while C. retusa and C. specatabilis induce hepatotoxicosis. The toxic principle in Crotalaria spp. are dehydropyrrolizidine alkaloids and their N-oxides. C. incana poisoning to livestock is rarely documented. This paper reports the clinical signs and pathological findings of a case of Crotalaria incana poisoning in a steer. The chemical finding of a potential toxic dehydropyrrolizidine alkaloid in the plant is documented for the first time.Case: The affected bovine was part of a herd of 80 two-year-old steers that were transferred from Property 1 to Property 2, 30 days prior to the event. In the pasture of Property I - where the steers were held for 6 months - there was a heavy infestation by a Crotalaria species with signs of being consumed by the steers. The plant was identified as Crotalaria incana at the Botanical Laboratory of the Federal University of Mato Grosso do Sul and a voucher specimen was filed there under the register GCMS 51169. Two days after entering Property 2 one of the steers became depressed, staggering, and in poor body condition. With time, the steer became oblivious to the environment and died 20 days after the onset of the clinical signs. Significant necropsy findings were limited to the liver which was markedly enlarged and with rounded edges. The hepatic cut surface was mottled with dark red and extensive orange areas of discoloration. The gallbladder was distended and the bile was inspissated. Microscopically, in the liver, there was fibrosis, bile duct hyperplasia and hepatocellular megalocytosis. The Glisson’s capsule was markedly thickened by fibrosis. In the brain, there was vacuolation of myelin sheaths (status spongiosus), moderate gliosis, and rare Alzheimer type 2 astrocytes.Discussion: The diagnosis of intoxication by C. incana was based on clinical signs and pathological changes and the evidence of the plant being consumed. The high infestation of C. incana in the pasture, the high proportion of dead matter and the low concentration of viable pasture favored the ingestion of C. incana. Spongy degeneration, a typical lesion of hepatic encephalopathy, was observed in the several areas of the brain. Cirrhosis of the liver as seen in the case of this report, results in elevated ammonia levels in the blood - and eventually in the brain – and ammonia toxicity causes hepatic encephalopathy. Morphological changes in hepatic encephalopathy in the central nervous system of human beings and horses centers on astrocytes which undergo Alzheimer type 2 change developing an enlarged, pale nuclei with a rim of chromatin and prominent nucleoli. Astrocytes pairs and triplets are seen, and, in severe cases, astrocytic nuclei may become lobulated and contain glycogen. Chemical analysis of C. incana was accomplished by acid-base extraction with zincreduction of N-oxides and quantitation by spectrometry. Quantitative analysis was achieved by liquid chromatography-mass spectrometry. To confirm the identity of the alkaloid in the sample of C. incana the isolated alkaloid was compared to a standard sample of usaramine previously isolated, and its identity verified by magnetic resonance spectroscopy analysis. The 1,2-dehydropyrrolizidine alkaloid usaramine, as well as its  N-oxide, were identified as the major alkaloids in in C. incana. The concentration found in the seed was consistent with that previously reported. This is a new finding on the toxic principle of C. incana. Keywords: cattle diseases, poisonous plants, pathology, hepatotoxicity, Crotalaria incana, chronic liver failure

Intoxicação espontânea e experimental por fumonisina em suínos no Brasil

Fumonisinas (FMN) são micotoxinas produzidas pelo fungo Fusarium (moniliforme) verticillioides que coloniza o milho no período pré-colheita. É descrito aqui um surto de intoxicação espontânea por fumonisina em suínos alimentados com quirera de milho (QM), um subproduto do processo de prélimpeza do milho. A QM estava contaminada com 112 ppm de FMN. Doze de 16 suínos morreram 5-6 dias após a QM contaminada ter sido introduzida em sua alimentação. Os sinais clínicos incluíam distúrbios respiratórios e avermelhamento da ponta das orelhas. Na necropsia, a lesão mais proeminente consistia de edema intersticial e alveolar associado com hidrotórax bilateral caracterizado por líquido citrino claro e translúcido. O cultivo da QM contaminada com FNM, realizada através de diluições seriadas e cultivo em meio DRBC, mostrou 6,7 X106 unidades formadoras de colônia por grama (UFC/g) e 96,6% dos fungos que cresceram eram espécies de Fusarium verticillioides e F. nygamai. Para confirmar o diagnóstico de intoxicação por fumonisina foi conduzido experimento usando quatro suínos jovens que foram alimentados com a mesma QM contaminada por FMN que havia sido consumida pelos suínos afetados espontaneamente. Cinco dias após o início do experimento, dois suínos foram sacrificados após apresentar sinais clínicos bem desenvolvidos que incluíam avermelhamento das pontas das orelhas e focinho e perturbações respiratórias. Os achados de necropsia e histopatológicos nos suínos do experimento foram os mesmos encontrados nos suínos afetados espontaneamente. Esta é a primeira descrição de intoxicação espontânea por fumonisina em suínos no Brasil

Acute Aflatoxicosis in Swines in Northeastern Brazil

Background: Aflatoxins are hepatotoxic mycotoxins derived from the secondary metabolism of toxigenic fungi belonging to the genus Aspergillus, especially A. flavus and A. parasiticus. Aflatoxin B1 is the most important metabolite, because of its deleterious effect mainly to the liver, especially for its carcinogenic, mutagenic and haemorrhagic properties, and usually is detected in higher concentrations in contaminated substrates. This paper reports the epidemiological, clinical, pathological and toxicological aspects of an outbreak of acute aflatoxicosis in pigs raised in Northeastern Brazil.Case: The cases occurred in a complete cycle farm, in the city of Mossoró, Rio Grande do Norte, Northeastern Brazil, in pigs ingesting low quality (moldy) corn being produced and processed on the farm. Sixty (73.1%) out of 82 two to five-months old pigs were clinicaly affected and 54 (65.8%) died. All animals showed fever, weight loss, tachycardia, tachypnea, lethargy, muscle tremors, muscle weakness and diarrhea. The clinical course ranged from five to 48 hours. Adult pigs were not affected. At necropsies, generalized jaundice, ascites, hydropericardium, petechial hemorrhages in the mesentery, subcutaneous edema and mesocolon were observed. The liver was yellow-orange with reddish diffuse multifocal areas, enlarged and extremely friable. Histologically there was swelling of hepatocytes with severe diffuse hepatocellular fatty degeneration, centrilobular hepatocellular necrosis, proliferation of bile ducts and cholestasis. High concentrations of aflatoxin B1 were determined in the corn (3400 μg/kg) and ration (1460 μg/kg).Discussion: The diagnosis of aflatoxicosis was based on epidemiological investigation associated with clinical and pathological findings and confirmed by high levels of aflatoxin B1 found in samples of corn and feed. Of the numerous types of aflatoxin reported, the most common is the B1, which is typically produced by Aspergillus fungi. In intensive pig farms, management conditions increase the chances of occurrence of intoxications caused by the poor quality of the grain (especially maize) by the poor quality of the grain (especially maize) used in the diet formulation. In the present report the corn was severely degraded and kept in physical conditions that favor the proliferation of aflatoxins. In addition, young animals, which are more suseptible, were the only ones affected with 73% morbidity and 65.8% mortality. In cases of spontaneous aflatoxicosis morbidity in pigs can vary from 10 to 100% and mortality is high when the diet has a high concentration of aflatoxins as observed in this outbreak (3400 and 1460 μg/kg of B1 in corn and food, respectively) . Increases in sérum ALT levels indicate hyperacute, acute or chronic active hepatocellular damage; a toxic hepatitis in this case. Furthermore, the increased serum AST suggest the existence of extensive and progressive hepatocellular damage, because this enzyme is synthesized mitochondrial level. Legislation in Brazil, determines that the maximum tolerated aflatoxin concentrations are 50 parts per million (ppm) or 50 μg/kg in food included in the diet formulation for animal consumption and 20 ppb in corn grain for human consumption. Differential diagnosis of aflatoxicosis include leptospirosis and intoxication by Crotalaria retusa or other pyrrolizidine alkaloids-containing plants.Keywords: aflatoxicosis, mycotoxins, toxic hepatitis, swine