PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Alves D.M., Marcolongo-Pereira C., Tavares L.A., Molarinho K.R., Raffi M.B., Schild A.L. & Sallis E.S.V. 2014. [Cattle in silvipasture system with eucalyptus: a risk for Ramaria flavo-brunnescens poisoning.] Criação de bovinos em sistema silvipastoril com eucalipto: um risco para intoxicação por Ramaria flavo-brunnescens. Pesquisa Veterinária Brasileira 34(7):659-662. Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Universidade Federal de Pelotas, Campus Universitário, Pelotas, RS 96010-900, Brazil. E-mail: esvsallis@yahoo.com.br The aim of this study was to describe and discuss the epidemiological aspects of spontaneous outbreaks of poisoning by Ramaria flavo-brunnescens in cattle maintained in silvipasture system in Southern Brazil. Three outbreaks of the disease between 2011 and 2013 were diagnosed. In two outbreaks morbidity was 35% and 37.4%, and the mortality rate was 36.12% and 16%, respectively. The fatality rate in these outbreaks was 45.71% and 96.55%. The diagnosis was confirmed by the epidemiology and the presence of the mushroom in the areas where the cattle grazed, in addition to the clinical signs, gross and histological lesions. The climatic data of temperature, humidity and rainfall were statistically analyzed and no significant differences were observed between the years 2007-2013. It was not possible to confirm that the presence of R. flavo-brunnescens in eucalyptus groves is associated with rainy autumns and warm dry summers. It is likely that other factors are associated with the presence of the mushroom in the woods and its toxicity. The soil and type of forest planted may also determine the presence of the mushroom in the area. It is possible that the species of eucalyptus is also a determining factor for the occurrence of the mushroom, since in many eucalyptus forests R. flavo-brunnescens does not occur. The recognition of the mushroom by workers and farmers and the time for its development in the eucalyptus woods is essential to minimize economic losses caused by the poisoning.

• Poisonous plants Ramaria flavo-brunnescens Clavariaceae plant poisoning mycotoxicosis plantas tóxicas intoxicação por plantas micotoxicose

Abstract in Portuguese:

RESUMO.- Alves D.M., Marcolongo-Pereira C., Tavares L.A., Molarinho K.R., Raffi M.B., Schild A.L. & Sallis E.S.V. 2014. [Cattle in silvipasture system with eucalyptus: a risk for Ramaria flavo-brunnescens poisoning.] Criação de bovinos em sistema silvipastoril com eucalipto: um risco para intoxicação por Ramaria flavo-brunnescens. Pesquisa Veterinária Brasileira 34(7):659-662. Laboratório Regional de Diagnóstico, Faculdade de Veterinária, Universidade Federal de Pelotas, Campus Universitário, Pelotas, RS 96010-900, Brazil. E-mail: esvsallis@yahoo.com.br O objetivo deste trabalho foi descrever e discutir os aspectos epidemiológicos de surtos de intoxicação espontânea por Ramaria flavo-brunnescens em bovinos criados em sistema silvippastoril na região sul do Rio Grande do Sul. Foram diagnosticados três surtos da enfermidade entre 2011 e 2013. Em dois surtos a morbidade foi de 35% e 37,4% e a mortalidade foi de 36,12% e 16%, respectivamente. A letalidade nos surtos foi de 45,71% e 96,55%. O diagnóstico foi confirmado pela epidemiologia e presença do cogumelo nas áreas onde os bovinos estavam, além dos sinais clínicos e lesões macroscópicas e histológicas características. Os dados climáticos de temperatura, umidade e precipitação pluviométrica foram analisados estatisticamente; não se observou diferenças de 2007 a 2013. Não foi possível confirmar se a presença de R. flavo-brunnescens nos bosques de eucaliptos está associada a outonos chuvosos e quentes após verões secos. É provável que outros fatores estejam associados à presença do cogumelo nos bosques e à sua toxicidade. A influência do solo e a finalidade da mata plantada podem também, determinar a presença ou não do cogumelo na área. É provável que a espécie de eucalipto seja também um fator determinante para a ocorrência do cogumelo, já que em muitas matas deste gênero o vegetal R. flavo-brunnecens não ocorre. O reconhecimento do cogumelo por trabalhadores e produtores rurais e a época em que o mesmo se desenvolve nos bosques de eucalipto é fundamental para minimizar as perdas econômicas causadas pela intoxicação.

Abstract in English:

ABSTRACT.- Schons S.V., Kommers G.D., Pereira G.M., Raffi M.B. & Schild A.L. 2007. [Microscopic, immunohistochemical, and ultra-structural study of the lesions experimentaly induced by Ramaria flavo-brunnescens (Clavariaceae) in cattle.] Estudo histológico, imuno-histoquímico e ultra-estrutural das lesões induzidas experimentalmente por Ramaria flavo-brunnescens (Clavariaceae) em bovinos. Pesquisa Veterinária Brasileira 27(7):269-276. Laboratório Regional de Diagnóstico, Universidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br The objective of this study was to investigate the pathogenesis of the lesions observed in cattle experimentally poisoned by Ramaria flavo-brunnescens. The mushroom was given to three 9 to10-month-old Jersey calves immediately after harvesting. Daily doses were around 20g/kg of body weight during 7 (Calf 1) or 13 days (Calves 2-3), and the total doses of mushroom given were 140, 268, and 261g/kg of body weight, respectively. One calf (Calf 4) with same age and breed was used as control. Clinical signs were characterized by prostration, anorexia, hyperemia of oral mucosa, and loosening of long hairs of the tail tip under mild traction. The calves were submitted to euthanasia and necropsied on days 8 (Calf 1) and 15 (Calves 2-4) after the beginning of the experiment. Microscopically, there was smoothness of dorsal epithelium of tongue with absence of filiform papillae, vacuolation of keratinocytes, and loosening of the keratin layer. In the hooves, there was vacuolation and irregular keratinization of the laminar epidermis and hyperplasia of keratinocytes. Hyperkeratosis, vacuolation of the external root sheath, thickening of tricholemal keratin, and inflammatory infiltration around hair follicles were observed on the skin of the tail tip. Immunohistochemical results with anti-pancytoceratin and anti-Ki67 (cell proliferation marker) antibodies showed no differences between the tongue dorsal epithelium of the control and experimental calves. Ultrastructural study demonstrated decrease in tonofilaments and increased intercellular spaces of the spinous layer of the tongue dorsal epithelium. The results of this study favor the hypothesis of an interference with the epithelial keratinization mechanisms by the toxic principles of Ramaria flavo-brunnescens.

• Ramaria flavo-brunnecens mushroom poisoning cattle diseases pathology

Abstract in Portuguese:

ABSTRACT.- Schons S.V., Kommers G.D., Pereira G.M., Raffi M.B. & Schild A.L. 2007. [Microscopic, immunohistochemical, and ultra-structural study of the lesions experimentaly induced by Ramaria flavo-brunnescens (Clavariaceae) in cattle.] Estudo histológico, imuno-histoquímico e ultra-estrutural das lesões induzidas experimentalmente por Ramaria flavo-brunnescens (Clavariaceae) em bovinos. Pesquisa Veterinária Brasileira 27(7):269-276. Laboratório Regional de Diagnóstico, Universidade Federal de Pelotas, Campus Universitário s/n, Pelotas, RS 96010-900, Brazil. E-mail: alschild@terra.com.br The objective of this study was to investigate the pathogenesis of the lesions observed in cattle experimentally poisoned by Ramaria flavo-brunnescens. The mushroom was given to three 9 to10-month-old Jersey calves immediately after harvesting. Daily doses were around 20g/kg of body weight during 7 (Calf 1) or 13 days (Calves 2-3), and the total doses of mushroom given were 140, 268, and 261g/kg of body weight, respectively. One calf (Calf 4) with same age and breed was used as control. Clinical signs were characterized by prostration, anorexia, hyperemia of oral mucosa, and loosening of long hairs of the tail tip under mild traction. The calves were submitted to euthanasia and necropsied on days 8 (Calf 1) and 15 (Calves 2-4) after the beginning of the experiment. Microscopically, there was smoothness of dorsal epithelium of tongue with absence of filiform papillae, vacuolation of keratinocytes, and loosening of the keratin layer. In the hooves, there was vacuolation and irregular keratinization of the laminar epidermis and hyperplasia of keratinocytes. Hyperkeratosis, vacuolation of the external root sheath, thickening of tricholemal keratin, and inflammatory infiltration around hair follicles were observed on the skin of the tail tip. Immunohistochemical results with anti-pancytoceratin and anti-Ki67 (cell proliferation marker) antibodies showed no differences between the tongue dorsal epithelium of the control and experimental calves. Ultrastructural study demonstrated decrease in tonofilaments and increased intercellular spaces of the spinous layer of the tongue dorsal epithelium. The results of this study favor the hypothesis of an interference with the epithelial keratinization mechanisms by the toxic principles of Ramaria flavo-brunnescens.

Abstract in English:

ABSTRACT.- Barros R.R., Irigoyen L.F., Kommers G.D., Rech R.R., Fighera R.A. & Barros C.S.L. 2006. [Poisoning by Ramaria flavo-brunnescens (Clavariaceae) in cattle.] Intoxicação por Ramaria flavo-brunnescens (Clavariaceae) em bovinos. Pesquisa Veterinária Brasileira 26(2):87-96. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two oubreaks of poisoning by the mushroom Ramaria flavo-brunnescens are reported in cattle from two farms located in the municipalities of Santa Maria and São Gabriel, state of Rio Grande do Sul, during April-May 2005. Out of a total of 180 yearling calves that had access to a pasture with eucalyptus woods, 19 were affected and 10 died. The clinical courses were 8-15 days and clinical signs included depression, weight loss, dehydration, drooling, loosening and loss of the long hairs of the tip of the tail, smoothening of the dorsal surface of the tongue with occasional ulceration, loosening of the corneal encasement of horns, hard and ball-shaped feces covered with a film of mucous, hypopion, hyphema and corneal opacity. Two calves had leucocytosis due to mild regenerative left shift. Nine calves were necropsied. Necropsy findings confirmed the clinical observation and additionaly included fibrinonecrotic esophagitis, mainly in the distal third of the esophageal mucosa. Histopathological changes in the skin of the tail included orthokeratotic hyperkeratosis; hair folicles with irregular contours, thickening of the tricolemmal keratin layer with occasional formation of keratin plugs, and degeneration and necrosis of the outer root sheath. At the laminar region of the hooves, there was hyperplasia of the top of epidermal laminae with irregular keratinization and retention of nuclei; several epidermal laminae were shortened and fused. There was hemorrhage, fibrin and neutrophilic infiltrate in the dermal laminae. In the mucosa of the tongue there was thinning of the covering epithelium, atrophy and loss of filiform papillae, multifocal areas of dyskeratosis, and spongiosis of the basal cell layer. In some parts the epithelium was lost and the surface consisted of granulation tissue and mixed inflammatory cell infiltrate. The esophageal mucosae of six calves had varying degree of epithelial necrosis and inflammation. The loss of the covering epithelium revealed an underneath area of granulation tissue with heavy inflammatory infiltrate composed predominantly of neutrophils and macrophages. In six calves there were focal symmetric bilateral areas of malacia observed at the level of obex in the medulla oblongata and affecting the white matter and parts of the dorsal nucleus of the vagus and of the hypoglossal nucleus. The epidemiology, clinical signs, pathology, and pathogenesis of poisoning by R. flavo-brunnescens in cattle are discussed.

• Poisonous plants Ramaria flavo-brunnescens Clavariaceae plant poisoning mushroom poisoning keratinization defect focal symmetric encephalomalacia diseases of cattle pathology.

Abstract in Portuguese:

ABSTRACT.- Barros R.R., Irigoyen L.F., Kommers G.D., Rech R.R., Fighera R.A. & Barros C.S.L. 2006. [Poisoning by Ramaria flavo-brunnescens (Clavariaceae) in cattle.] Intoxicação por Ramaria flavo-brunnescens (Clavariaceae) em bovinos. Pesquisa Veterinária Brasileira 26(2):87-96. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two oubreaks of poisoning by the mushroom Ramaria flavo-brunnescens are reported in cattle from two farms located in the municipalities of Santa Maria and São Gabriel, state of Rio Grande do Sul, during April-May 2005. Out of a total of 180 yearling calves that had access to a pasture with eucalyptus woods, 19 were affected and 10 died. The clinical courses were 8-15 days and clinical signs included depression, weight loss, dehydration, drooling, loosening and loss of the long hairs of the tip of the tail, smoothening of the dorsal surface of the tongue with occasional ulceration, loosening of the corneal encasement of horns, hard and ball-shaped feces covered with a film of mucous, hypopion, hyphema and corneal opacity. Two calves had leucocytosis due to mild regenerative left shift. Nine calves were necropsied. Necropsy findings confirmed the clinical observation and additionaly included fibrinonecrotic esophagitis, mainly in the distal third of the esophageal mucosa. Histopathological changes in the skin of the tail included orthokeratotic hyperkeratosis; hair folicles with irregular contours, thickening of the tricolemmal keratin layer with occasional formation of keratin plugs, and degeneration and necrosis of the outer root sheath. At the laminar region of the hooves, there was hyperplasia of the top of epidermal laminae with irregular keratinization and retention of nuclei; several epidermal laminae were shortened and fused. There was hemorrhage, fibrin and neutrophilic infiltrate in the dermal laminae. In the mucosa of the tongue there was thinning of the covering epithelium, atrophy and loss of filiform papillae, multifocal areas of dyskeratosis, and spongiosis of the basal cell layer. In some parts the epithelium was lost and the surface consisted of granulation tissue and mixed inflammatory cell infiltrate. The esophageal mucosae of six calves had varying degree of epithelial necrosis and inflammation. The loss of the covering epithelium revealed an underneath area of granulation tissue with heavy inflammatory infiltrate composed predominantly of neutrophils and macrophages. In six calves there were focal symmetric bilateral areas of malacia observed at the level of obex in the medulla oblongata and affecting the white matter and parts of the dorsal nucleus of the vagus and of the hypoglossal nucleus. The epidemiology, clinical signs, pathology, and pathogenesis of poisoning by R. flavo-brunnescens in cattle are discussed.