PESQUISA VETERINÁRIA BRASILEIRA

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.- Silva M.C., Fighera R.A., Brum J.S., Graça D.L., Kommers G.D., Irigoyen L.F. & Barros C.S.L. 2007. [Clinicopathological features in 620 neurological cases of canine distemper.] Aspectos clinicopatológicos de 620 casos neurológicos de cinomose em cães. Pesquisa Veterinária Brasileira 27(5):215-220. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The files of 5,361 necropsies performed in dogs in the Veterinary Pathology Laboratory of the Federal University of Santa Maria during 1965-2006 were reviewed in search of cases of canine distemper. Six hundred and eighty three cases (12.7%) of the disease were found, 620 of which had neurological signs. From those 620, the following data on each case were retrieved: age, clinical signs, histopathology and concomitance or not of another disease. Age groups were classified as puppies (up to 1 year of age), adults (from 1 to 9 years) and aged (from 10 years on). In 565 out of the 620 (91.1%) neurological cases of canine distemper, histopathological brain changes were observed and in 554 of those 565 the age was registered in the files with following age group distribution: 45.9% of puppies, 51.4% of adults, and 2.7% of aged dogs. Neurological clinical signs encompassed a large spectrum of motor, postural and behavioral disturbances which could occur together or individually. Most frequent clinical signs were myoclonus (38.4%), motor incoordination (25.0%), seizures (18.5%), and paraplegia (13.4%). In 98.4% of the 565 dogs with histopathological changes in the brain demyelination, non-suppurative encephalitis or a combination of these two were found. Intranuclear eosinophilic inclusion bodies were observed in different brain cells of 343 of the 565 dogs with histopathological changes. In 170 (49.6%) the cellular type bearing the inclusions was not mentioned in the file and in the remaining cases the inclusions were seen in astrocytes (94.8% of the cases), neurons (3.5%), oligodendrocytes (1.1%), and ependyma cells (0.6%). Taking in consideration the type of lesions and the age groups, cases with combined demyelination and non-suppurative encephalitis occurred in 40.0% of the puppies, 51.2% of the adult dogs and 72.7% of the aged dogs. Demyelination alone occurred in 48.4% of the puppies, 41.3% of the adults and in 35.7% of the aged dogs. Non-suppurative encephalitis alone occurred 11.6% of the puppies, 7.5% of the adults and in 7.1% of the aged dogs.

• Infectious diseases canine distemper neurology neuropathology pathology diseases of dogs

Abstract in Portuguese:

ABSTRACT.- Silva M.C., Fighera R.A., Brum J.S., Graça D.L., Kommers G.D., Irigoyen L.F. & Barros C.S.L. 2007. [Clinicopathological features in 620 neurological cases of canine distemper.] Aspectos clinicopatológicos de 620 casos neurológicos de cinomose em cães. Pesquisa Veterinária Brasileira 27(5):215-220. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The files of 5,361 necropsies performed in dogs in the Veterinary Pathology Laboratory of the Federal University of Santa Maria during 1965-2006 were reviewed in search of cases of canine distemper. Six hundred and eighty three cases (12.7%) of the disease were found, 620 of which had neurological signs. From those 620, the following data on each case were retrieved: age, clinical signs, histopathology and concomitance or not of another disease. Age groups were classified as puppies (up to 1 year of age), adults (from 1 to 9 years) and aged (from 10 years on). In 565 out of the 620 (91.1%) neurological cases of canine distemper, histopathological brain changes were observed and in 554 of those 565 the age was registered in the files with following age group distribution: 45.9% of puppies, 51.4% of adults, and 2.7% of aged dogs. Neurological clinical signs encompassed a large spectrum of motor, postural and behavioral disturbances which could occur together or individually. Most frequent clinical signs were myoclonus (38.4%), motor incoordination (25.0%), seizures (18.5%), and paraplegia (13.4%). In 98.4% of the 565 dogs with histopathological changes in the brain demyelination, non-suppurative encephalitis or a combination of these two were found. Intranuclear eosinophilic inclusion bodies were observed in different brain cells of 343 of the 565 dogs with histopathological changes. In 170 (49.6%) the cellular type bearing the inclusions was not mentioned in the file and in the remaining cases the inclusions were seen in astrocytes (94.8% of the cases), neurons (3.5%), oligodendrocytes (1.1%), and ependyma cells (0.6%). Taking in consideration the type of lesions and the age groups, cases with combined demyelination and non-suppurative encephalitis occurred in 40.0% of the puppies, 51.2% of the adult dogs and 72.7% of the aged dogs. Demyelination alone occurred in 48.4% of the puppies, 41.3% of the adults and in 35.7% of the aged dogs. Non-suppurative encephalitis alone occurred 11.6% of the puppies, 7.5% of the adults and in 7.1% of the aged dogs.

Abstract in English:

ABSTRACT.- Barros C.S.L., Castilhos L.M.L., Rissi D.R., Kommers G.D. & Rech R.R. 2007. [Liver biopsy for the diagnosis of Senecio brasiliensis (Asteraceae) poisoning in cattle.] Biópsia hepática no diagnóstico da intoxicação por Senecio brasiliensis (Asteraceae) em bovinos. Pesquisa Veterinária Brasileira 27(1):53-60. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Liver lesions caused by Senecio spp. poisoning in cattle are progressive and deaths may occur many months after the plant is ingested. Laboratory tests of liver function are not always reliable indicators of subclinical affected animals. Liver biopsy could be useful to identify cattle with hepatic lesions but without clinical signs and would have also a prognostic value since it is generally believed that hepatic lesions will eventually cause liver failure and death. Such animals could be picked out by liver biopsy before clinical signs develop and be sent to slaughter, minimizing economic losses. This study was aimed to evaluate the liver biopsy as a diagnostic and prognostic tool in cases of Senecio spp. poisoning in cattle. An outbreak of Senecio brasiliensis was diagnosed in dairy calves which ingested hay contaminated by 5-10% of this Senecio species. Liver biopsy using a Menghini needle by right transthoracic approach was carried out in 135 calves that ingested the contaminated hay. Biopsed calves were followed up for 26 months after the biopsy. Seventeen biopsied calves had typical lesions of Senecio spp. poisoning (positive calves) and 118 had histologically normal livers (negative calves). Hepatic lesions of positive calves included fibrosis, hepatomeglocytosis, and biliary hyperplasia. Fifteen out of the 17 positive calves died with typical clinical signs of Senecio spp. poisoning within 17-149 days after the biopsy; 13 of those were necropsied and had typical gross and histopathological lesions of Senecio spp. poisoning. Two positive calves were clinically normal at the end of the post-biopsy observation period. The prognostic value (sensibility) of the test was considered high since 88.23% of the positive calves died. The specificity of the test was considered very high (99.16%) since only one of the 118 negative calves died in the observation period. In none of the biopsed calves a negative effect related to the biopsy technique was observed.

• Poisonous plants Senecio brasiliensis Asteraceae liver biopsy diseases of cattle pathology

Abstract in Portuguese:

ABSTRACT.- Barros C.S.L., Castilhos L.M.L., Rissi D.R., Kommers G.D. & Rech R.R. 2007. [Liver biopsy for the diagnosis of Senecio brasiliensis (Asteraceae) poisoning in cattle.] Biópsia hepática no diagnóstico da intoxicação por Senecio brasiliensis (Asteraceae) em bovinos. Pesquisa Veterinária Brasileira 27(1):53-60. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Liver lesions caused by Senecio spp. poisoning in cattle are progressive and deaths may occur many months after the plant is ingested. Laboratory tests of liver function are not always reliable indicators of subclinical affected animals. Liver biopsy could be useful to identify cattle with hepatic lesions but without clinical signs and would have also a prognostic value since it is generally believed that hepatic lesions will eventually cause liver failure and death. Such animals could be picked out by liver biopsy before clinical signs develop and be sent to slaughter, minimizing economic losses. This study was aimed to evaluate the liver biopsy as a diagnostic and prognostic tool in cases of Senecio spp. poisoning in cattle. An outbreak of Senecio brasiliensis was diagnosed in dairy calves which ingested hay contaminated by 5-10% of this Senecio species. Liver biopsy using a Menghini needle by right transthoracic approach was carried out in 135 calves that ingested the contaminated hay. Biopsed calves were followed up for 26 months after the biopsy. Seventeen biopsied calves had typical lesions of Senecio spp. poisoning (positive calves) and 118 had histologically normal livers (negative calves). Hepatic lesions of positive calves included fibrosis, hepatomeglocytosis, and biliary hyperplasia. Fifteen out of the 17 positive calves died with typical clinical signs of Senecio spp. poisoning within 17-149 days after the biopsy; 13 of those were necropsied and had typical gross and histopathological lesions of Senecio spp. poisoning. Two positive calves were clinically normal at the end of the post-biopsy observation period. The prognostic value (sensibility) of the test was considered high since 88.23% of the positive calves died. The specificity of the test was considered very high (99.16%) since only one of the 118 negative calves died in the observation period. In none of the biopsed calves a negative effect related to the biopsy technique was observed.

Abstract in English:

ABSTRACT.- Rech R.R., Rissi D.R., Rodrigues A., Pierezan F., Piazer J.V.M., Kommers G.D. & Barros C.S.L. 2006. [Poisoning by Solanum fastigiatum (Solanaceae) in cattle: epidemiology, clinical signs and morphometry of cerebellar lesions.] Intoxicação por Solanum fastigiatum (Solanaceae) em bovinos: epidemiologia, sinais clínicos e morfometria das lesões cerebelares. Pesquisa Veterinária Brasileira 26(3):183-189. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Nineteen cases of Solanum fastigiatum (Solanaceae) poisoning in cattle from three municipalites in the State of Rio Grande do Sul, Brazil, occurring from 2003 to 2005, are described. Morbidity and mortality rates were respectively 6.7% and 3.4%. Average age of affected cattle was five-year-old (2 to 8-year-old) and duration of clinical courses was 3-18 months. Clinical signs observed in all affected cattle were cerebellar deficits characterized by hypermetry, incoordination, falls, muscle tremors, transitory seizures and wide base stance. One affected bovine had encephalic traumatic subdural hemorrhage and another had gross atrophy of the cerebellum. Histologically, lesions were restricted to the cerebellum and consisted of partial or complete vacuolation of the perikaria of Purkinje neurons with occasional axonal spheroids in the granular cell layer and in the white matter of the cerebellum. In advanced cases there were extensive loss of cerebellar Purkinje neurons and proliferation of the Bergmann’s glia. The morphometric evaluation of the numbers of Purkinje neurons and of the thickness of the cerebellar molecular layer indicated decreased numbers of Purkinje neurons with consequent decrease in the molecular layer thickness.

• Poisonous plants Solanum fastigiatum Solanaceae lysosomal storage diseases central nervous system diseases of cattle neuropathology

Abstract in Portuguese:

ABSTRACT.- Rech R.R., Rissi D.R., Rodrigues A., Pierezan F., Piazer J.V.M., Kommers G.D. & Barros C.S.L. 2006. [Poisoning by Solanum fastigiatum (Solanaceae) in cattle: epidemiology, clinical signs and morphometry of cerebellar lesions.] Intoxicação por Solanum fastigiatum (Solanaceae) em bovinos: epidemiologia, sinais clínicos e morfometria das lesões cerebelares. Pesquisa Veterinária Brasileira 26(3):183-189. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Nineteen cases of Solanum fastigiatum (Solanaceae) poisoning in cattle from three municipalites in the State of Rio Grande do Sul, Brazil, occurring from 2003 to 2005, are described. Morbidity and mortality rates were respectively 6.7% and 3.4%. Average age of affected cattle was five-year-old (2 to 8-year-old) and duration of clinical courses was 3-18 months. Clinical signs observed in all affected cattle were cerebellar deficits characterized by hypermetry, incoordination, falls, muscle tremors, transitory seizures and wide base stance. One affected bovine had encephalic traumatic subdural hemorrhage and another had gross atrophy of the cerebellum. Histologically, lesions were restricted to the cerebellum and consisted of partial or complete vacuolation of the perikaria of Purkinje neurons with occasional axonal spheroids in the granular cell layer and in the white matter of the cerebellum. In advanced cases there were extensive loss of cerebellar Purkinje neurons and proliferation of the Bergmann’s glia. The morphometric evaluation of the numbers of Purkinje neurons and of the thickness of the cerebellar molecular layer indicated decreased numbers of Purkinje neurons with consequent decrease in the molecular layer thickness.

Abstract in English:

ABSTRACT.- Almeida A.P.M.G., Kommers G.D., Nogueira A.P.A., Júnior L.G.B., Marques B.M.F.P. & Lemos R.A.A. 2006. [Evaluation of the toxicity of Leucaena leucocephala (Leg. Mimosoi-deae) in sheep.] Avaliação do efeito tóxico de Leucaena leucocephala (Leg.Mimosoideae) em ovinos. Pesquisa Veterinária Brasileira 26(3):190-194. Departamento de Medicina Veterinária, Faculdade de Medicina Vetetinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Av. Senador Filinto Müller 2443, Cx.Postal 549, Campo Grande, MS 79070-900, Brazil. E-mail: eqrural@nin.ufms.br An experiment was performed to evaluate the toxicity of Leucaena leucocephala for sheep. Two ewes and six lambs were divided into seven treatments and fed the plant. The adult ewes did not show clinical signs of poisoning. The 4 to 5-month-old lambs presented partial wool loss 6 days after beginning of the administration of the plant and total wool loss after 12 or 20 days. The age of the sheep in this experiment suggests resistance of adult ewes and susceptibility of young lambs to L. leucocaephala poisoning.

• Poisonous plants Leucaena leucocephala Leguminosae Mimosoideae plant poisoning sheep diseases pathology

Abstract in Portuguese:

ABSTRACT.- Almeida A.P.M.G., Kommers G.D., Nogueira A.P.A., Júnior L.G.B., Marques B.M.F.P. & Lemos R.A.A. 2006. [Evaluation of the toxicity of Leucaena leucocephala (Leg. Mimosoi-deae) in sheep.] Avaliação do efeito tóxico de Leucaena leucocephala (Leg.Mimosoideae) em ovinos. Pesquisa Veterinária Brasileira 26(3):190-194. Departamento de Medicina Veterinária, Faculdade de Medicina Vetetinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Av. Senador Filinto Müller 2443, Cx.Postal 549, Campo Grande, MS 79070-900, Brazil. E-mail: eqrural@nin.ufms.br An experiment was performed to evaluate the toxicity of Leucaena leucocephala for sheep. Two ewes and six lambs were divided into seven treatments and fed the plant. The adult ewes did not show clinical signs of poisoning. The 4 to 5-month-old lambs presented partial wool loss 6 days after beginning of the administration of the plant and total wool loss after 12 or 20 days. The age of the sheep in this experiment suggests resistance of adult ewes and susceptibility of young lambs to L. leucocaephala poisoning.

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.

Abstract in English:

ABSTRACT.- Moreira Souto M.A., Kommers G.D., Barros C.S.L., Piazer J.V.M., Rech R.R., Riet-Correa F. & Schild A.L. 2006. [Neoplasms of the upper digestive tract of cattle associated with spontaneous ingestion of bracken fern (Pteridium aquilinum).] Neoplasias do trato alimentar superior de bovinos associadas ao consumo espontâneo de samambaia (Pteridium aquilinum). Pesquisa Veterinária Brasileira 26(2):112-122. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: glaukommers@yahoo.com Thirty bovine with neoplasms of the upper digestive tract (UDT) associated with spontaneous ingestion of bracken fern (Pteridium aquilinum) were studied. They were from 27 farms, located in the municipalities of Jaguari (23) and Nova Esperança do Sul (4), Rio Grande do Sul, Brazil. The total cattle population in those farms was 1,090 and large amounts of bracken fern were found in the pastures. Twenty-six of the affected cattle were cows and four were castrated males, 3-13 years of age; most of them were 7-8 years old (46,6%). Clinical signs observed in the affected animals were progressive weight loss, absence of ruminal movements, cough, dysphagia, regurgitation, halitosis, diarrhea, and bloat. Less frequent signs were selective appetite, dyspnea, and salivation. Two bovine died and 28 were submitted to euthanasia in advanced stage of disease and necropsied. The main gross and microscopic alterations were found in identical areas of the UDT. They consisted of papillomas, transforming papillomas, and squamous cell carcinomas (SCCs). Metastases of SCCs to regional lymph nodes and other organs, such as liver and lungs, were also observed (18/30). Twenty-nine bovine had papillomas of various sizes in several areas of the UDT. The digestive papillomatosis ranged from mild (45%), to moderate (38%), to severe (17%). Three developing phases were observed microscopically in the examined papillomas: an early growing phase, a developing phase, and a regressing phase. In 16 cases, there was malignant transformation of papillomas into SCCs. The SCCs were solitary (12/30) or multiple (18/30) and were histologically well, moderately, or poorly differentiated. Grouping the distribution of SCCs of larger extension in the UDT into cranial region (base of the tongue, pharynx/oropharynx, and epiglottis), medial region (esophagus), and caudal region (cardia and rumen), the distribution was cranial in 39%, middle in 16%, and caudal in 45% of the cases. By the same grouping criteria, but considering the total number of times SCCs of varied extensions were diagnosed in the cranial, middle, and caudal regions, the percentages changed to 34%, 26%, and 40%, respectively. The epidemiological and histomorphological evidences found in this study are in agreement with the observations that point out the co-carcinogenesis between bovine papillomavirus type 4 infection and chemicals of bracken fern in the pathogenesis of the SCCs in the UDT of cattle. However, the presence of pre-neoplastic changes and SCCs in situ or in early stages of development, independently of the presence of papillomas, clearly indicates the possibility of development of SCCs from normal epithelium, probably due to the direct action of the chemical carcinogens contained in bracken fern.

• Poisonous plants Pteridium aquilinum plant poisoning bovine papillomavirus type 4 squamous cell carcinoma diseases of cattle pathology.

Abstract in Portuguese:

ABSTRACT.- Moreira Souto M.A., Kommers G.D., Barros C.S.L., Piazer J.V.M., Rech R.R., Riet-Correa F. & Schild A.L. 2006. [Neoplasms of the upper digestive tract of cattle associated with spontaneous ingestion of bracken fern (Pteridium aquilinum).] Neoplasias do trato alimentar superior de bovinos associadas ao consumo espontâneo de samambaia (Pteridium aquilinum). Pesquisa Veterinária Brasileira 26(2):112-122. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: glaukommers@yahoo.com Thirty bovine with neoplasms of the upper digestive tract (UDT) associated with spontaneous ingestion of bracken fern (Pteridium aquilinum) were studied. They were from 27 farms, located in the municipalities of Jaguari (23) and Nova Esperança do Sul (4), Rio Grande do Sul, Brazil. The total cattle population in those farms was 1,090 and large amounts of bracken fern were found in the pastures. Twenty-six of the affected cattle were cows and four were castrated males, 3-13 years of age; most of them were 7-8 years old (46,6%). Clinical signs observed in the affected animals were progressive weight loss, absence of ruminal movements, cough, dysphagia, regurgitation, halitosis, diarrhea, and bloat. Less frequent signs were selective appetite, dyspnea, and salivation. Two bovine died and 28 were submitted to euthanasia in advanced stage of disease and necropsied. The main gross and microscopic alterations were found in identical areas of the UDT. They consisted of papillomas, transforming papillomas, and squamous cell carcinomas (SCCs). Metastases of SCCs to regional lymph nodes and other organs, such as liver and lungs, were also observed (18/30). Twenty-nine bovine had papillomas of various sizes in several areas of the UDT. The digestive papillomatosis ranged from mild (45%), to moderate (38%), to severe (17%). Three developing phases were observed microscopically in the examined papillomas: an early growing phase, a developing phase, and a regressing phase. In 16 cases, there was malignant transformation of papillomas into SCCs. The SCCs were solitary (12/30) or multiple (18/30) and were histologically well, moderately, or poorly differentiated. Grouping the distribution of SCCs of larger extension in the UDT into cranial region (base of the tongue, pharynx/oropharynx, and epiglottis), medial region (esophagus), and caudal region (cardia and rumen), the distribution was cranial in 39%, middle in 16%, and caudal in 45% of the cases. By the same grouping criteria, but considering the total number of times SCCs of varied extensions were diagnosed in the cranial, middle, and caudal regions, the percentages changed to 34%, 26%, and 40%, respectively. The epidemiological and histomorphological evidences found in this study are in agreement with the observations that point out the co-carcinogenesis between bovine papillomavirus type 4 infection and chemicals of bracken fern in the pathogenesis of the SCCs in the UDT of cattle. However, the presence of pre-neoplastic changes and SCCs in situ or in early stages of development, independently of the presence of papillomas, clearly indicates the possibility of development of SCCs from normal epithelium, probably due to the direct action of the chemical carcinogens contained in bracken fern.

Abstract in English:

Rissi D.R., Rech R.R., Barros R.R., Kommers G.D., Langohr I.M., Pierezan F. & Barros C.S.L. 2006. [Listeric meningoencephalitis in goats.] Forma nervosa de listeriose em caprinos. Pesquisa Veterinária Brasileira 26(1):14-20. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br A neurologic disease was observed in three young adult goats (indentified as A-C) from a herd of 100 goats during October-December, 2004. Clinical signs included head tilt, torticollis, nystagmus, staggering, falls and eventually recumbency and paddling, with stiff limbs. Treatment of Goat C with antibiotics resulted in a temporary remission of the clinical signs. The clinical courses where 5, 10 and 30 days respectively for Goats A, B and C. Goat A died spontaneously and the other two where euthanatized in extremis. No gross changes were observed. Histologic lesions were predominantly unilateral, with inflammatory and degenerative changes, extending from the medulla oblongata to the thalamus. In all 3 cases there were perivascular cuffings of one or more types of mononuclear cells (lymphocytes, plasma cells, activated macrophages) and occasionally neutrophils associated with areas of malacia where Gitter cells filled spaces of parenchymal loss. Additionally, Goat B had microabscesses in the medulla, pons, and mesencephalon and multifocal neutrophilic and lymphocytic infiltrates within the fascicles of the trigeminal nerve and in the cerebellar leptomeninges. In the brainstem of Goat C, there was multifocal granulomatous inflammation which included epithelioid macrophages and occasional multinucleated giant cells. Listeria sp antigen was detected by imunohistochemistry in routinely processed sections of mesencephalon from Goats A and C and of pons from Goat B.

• Listeria sp Listeria monocytogenes listeriosis encephalitis immunohistochemistry pathology diseases of goats.

Abstract in Portuguese:

Rissi D.R., Rech R.R., Barros R.R., Kommers G.D., Langohr I.M., Pierezan F. & Barros C.S.L. 2006. [Listeric meningoencephalitis in goats.] Forma nervosa de listeriose em caprinos. Pesquisa Veterinária Brasileira 26(1):14-20. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br A neurologic disease was observed in three young adult goats (indentified as A-C) from a herd of 100 goats during October-December, 2004. Clinical signs included head tilt, torticollis, nystagmus, staggering, falls and eventually recumbency and paddling, with stiff limbs. Treatment of Goat C with antibiotics resulted in a temporary remission of the clinical signs. The clinical courses where 5, 10 and 30 days respectively for Goats A, B and C. Goat A died spontaneously and the other two where euthanatized in extremis. No gross changes were observed. Histologic lesions were predominantly unilateral, with inflammatory and degenerative changes, extending from the medulla oblongata to the thalamus. In all 3 cases there were perivascular cuffings of one or more types of mononuclear cells (lymphocytes, plasma cells, activated macrophages) and occasionally neutrophils associated with areas of malacia where Gitter cells filled spaces of parenchymal loss. Additionally, Goat B had microabscesses in the medulla, pons, and mesencephalon and multifocal neutrophilic and lymphocytic infiltrates within the fascicles of the trigeminal nerve and in the cerebellar leptomeninges. In the brainstem of Goat C, there was multifocal granulomatous inflammation which included epithelioid macrophages and occasional multinucleated giant cells. Listeria sp antigen was detected by imunohistochemistry in routinely processed sections of mesencephalon from Goats A and C and of pons from Goat B.

Abstract in English:

Rissi D.R., Rech R.R., Fighera R.A., Cagnini D.Q., Kommers G.D. & Barros C.S.L. 2005. [Spontaneous Baccharis coridifolia poisoning in cattle.] Intoxicação espontânea por Baccharis coridifolia em bovinos. Pesquisa Veterinária Brasileira 25(2):111-114. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two outbreaks of Baccharis coridifolia poisoning in cattle in southern Brazil are described. Cases occurred when stressed, hungry and thirsty cattle brought from pastures free of B. coridifolia were placed into pastures heavily infested by this poisonous plant. In the two outbreaks morbidity was 21.73% and 22.51% and lethality was virtually 100%. Clinical signs included mild bloat, instability of hind limbs, muscle tremors, dry muzzle, dry feces or diarrhea, polydipsia and restlessness. Consistent necropsy findings included dehydration, large amounts of ruminal fluid, reddening and erosions of the mucosae of the forestomachs. Degeneration and necrosis of the lining epithelium of the forestomachs and of lymphoid tissue were the main histopathological changes encountered.

• Poisonous plants Baccharis coridifolia Asteraceae diseases of cattle pathology.

Abstract in Portuguese:

Rissi D.R., Rech R.R., Fighera R.A., Cagnini D.Q., Kommers G.D. & Barros C.S.L. 2005. [Spontaneous Baccharis coridifolia poisoning in cattle.] Intoxicação espontânea por Baccharis coridifolia em bovinos. Pesquisa Veterinária Brasileira 25(2):111-114. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Two outbreaks of Baccharis coridifolia poisoning in cattle in southern Brazil are described. Cases occurred when stressed, hungry and thirsty cattle brought from pastures free of B. coridifolia were placed into pastures heavily infested by this poisonous plant. In the two outbreaks morbidity was 21.73% and 22.51% and lethality was virtually 100%. Clinical signs included mild bloat, instability of hind limbs, muscle tremors, dry muzzle, dry feces or diarrhea, polydipsia and restlessness. Consistent necropsy findings included dehydration, large amounts of ruminal fluid, reddening and erosions of the mucosae of the forestomachs. Degeneration and necrosis of the lining epithelium of the forestomachs and of lymphoid tissue were the main histopathological changes encountered.

Abstract in English:

ABSTRACT.- Leal A.B.M., Leal A.T., Santurio J.M., Kommers G.D. & Catto J.B. 2001. [Equine pythiosis in the Brazilian Pantanal region: Clinical and pathological findings of typical and atypical cases] Pitiose eqüina no Pantanal brasileiro: aspectos clínico-patológicos de casos típicos e atípicos. Pesquisa Veterinária Brasileira 21(4):151-156. Laboratório de Pesquisas Micológicas, Depto Microbiologia e Parasitologia, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brazil. E-mail: santurio@ccr.ufsm.br Equine pythiosis is an endemic disease of horses and causes significant economic losses to equine breeding in the Brazilian Pantanal. This article describes 16 cases of subcutaneous pythiosis in horses from that region. The clinical cases were divided in typical (11) and atypical (5), according to the clinical features and duration of the disease. The clinical diagnosis was confirmed by detection of specific antibodies by ELISA, isolation of the agent and histopathology. The duration of the disease varie d from 1 to 6 months in the typical cases and was over 12 months in the atypical ones. The lesions in the typical cases were characterized by subcutaneous ulcerated granulomas with abundant serosanguineous secretion and itching. The atypical cases presented subcutaneous lesions characterized by large, circumscribed tumorous masses covered by a dark non ulcerated skin, associated with Iittle orno secretion. These lesions showed a well organized aspect, were sometimes pedunculate and the animals showed a good body condition. Histologically, the typical cases were characterized by granulation tissue with abundant eosinophils; whereas the atypical cases presented pseudoepitheliomatous hyperplasia of the epidermis and eosinophilic infiltrate. The complete description of the clinical and histopathological features and possible factors responsible for differences between the two clinical forms are presented and discussed.

• Pythiosis Pythium insidiosum equine granuloma Pantanal Pitiose granuloma eqüino Pantanal.

Abstract in Portuguese:

RESUMO.- Leal A.B.M., Leal A.T., Santurio J.M., Kommers G.D. & Catto J.B. 2001. [Equine pythiosis in the Brazilian Pantanal region: Clinical and pathological findings of typical and atypical cases] Pitiose eqüina no Pantanal brasileiro: aspectos clínico-patológicos de casos típicos e atípicos. Pesquisa Veterinária Brasileira 21(4):151-156. Laboratório de Pesquisas Micológicas, Depto Microbiologia e Parasitologia, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brazil. E-mail: santurio@ccr.ufsm.br A pitiose eqüina é doença endêmica no Pantanal Brasileiro e causa prejuízos significativos a eqüinocultura. Neste trabalho são relatados 16 casos de pitiose subcutânea em eqüinos no Pantanal Sul-Matogrossense, que foram divididos em onze casos típicos e cinco casos atípicos, de acordo com o quadro clínico e o tempo de duração das lesões. O diagnóstico foi confirmado pela detecção de anticorpos específicos pelo teste ELISA, isolamento do agente e histopatológico. A duração da doença variou entre 1 e 6 meses nos casos típicos e superior a 12 meses nos casos atípicos. As lesões dos casos típicos caracterizavam-se por granulomas subcutâneos, ulcerados, com abundante secreção serossanguinolenta e prurido. Nos casos atípicos foram observadas lesões subcutâneas caracterizadas por grandes massas "tumorais" circunscritas, recobertas por pele escura, sem ulcerações e com pouca secreção. Os animais estavam em bom estado nutricional e as lesões apresentavam-se de aspecto organizado, às vezes pedunculadas. Histologicamente, foi observado tecido de granulação com muitos eosinófilos nos casos típicos, enquanto os atípicos, se caracterizaram por hiperplasia pseudo-epiteliomatosa da epiderme e infiltrado eosinofilico. As características clínicas e histopato lógicas completas das duas formas clínicas e os possíveis fatores responsáveis pelas diferenças entre as duas formas são apresentados e discutidos.