PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Periodontitis is an inflammatory process of infectious origin affecting the teeth and their supporting structures, causing significant economic losses and reducing animal welfare. Bacteria in the gingival biofilm are one of the main factors in initiating inflammatory lesions. Bacteria act directly on tissues or indirectly through substances that cause tissue damage. Studies on the etiopathogenesis of periodontitis in Brazilian sheep herds are scarce. The present study aimed to characterize histologically periodontal lesions of culled sheep from the Brazilian breed, Santa Inês. Periodontal lesions, such as periodontal pockets containing plant tissue and bacteria, replacement of the periodontal ligament by connective tissue and inflammatory cells, superficial pustules, hydropic epithelial degeneration, and epithelium hyperplasia, were observed. Submucosal changes were characterized by granulation tissue, edema, swelling of the endothelial cells, bacteria, and predominantly perivascular lymphoplasmacytic inflammatory infiltrate. In the alveolar bone, osteoclastic resorption and bone apposition were observed. This study revealed subacute to chronic inflammation, alveolar bone resorption, and cortical bone apposition in ovine periodontitis. Thus, these findings can contribute to the evolution of knowledge about the etiopathogenesis of ovine periodontitis and, possibly, the development of measures to control the disease.

• Sheep diseases pathology ovine sheep periodontitis periodontal disease anaerobic histopathology.

Abstract in Portuguese:

A periodontite é um processo inflamatório de origem infecciosa que afeta os dentes e suas estruturas de suporte, causando perdas econômicas significativas e redução do bem-estar animal. As bactérias do biofilme gengival são um dos principais fatores envolvidos no início das lesões inflamatórias. As bactérias agem diretamente nos tecidos ou indiretamente por meio de substâncias que causam dano tecidual. Estudos sobre a etiopatogenia da periodontite em rebanhos ovinos brasileiros são escassos. O presente estudo teve como objetivo caracterizar histologicamente as lesões periodontais de ovinos de descarte da raça brasileira Santa Inês. Foram observadas lesões periodontais, como bolsas periodontais contendo tecido vegetal e bactérias, substituição do ligamento periodontal por tecido conjuntivo e células inflamatórias, pústulas superficiais, degeneração hidrópica epitelial e hiperplasia do epitélio. As alterações da submucosa foram caracterizadas por tecido de granulação, edema, tumefação das células endoteliais, bactérias e infiltrado inflamatório linfoplasmocitário predominantemente perivascular. No osso alveolar, observou-se reabsorção osteoclástica e aposição óssea. Este estudo revelou inflamação subaguda a crônica, reabsorção óssea alveolar e aposição de osso cortical na periodontite ovina. Assim, esses achados podem contribuir para a evolução do conhecimento sobre a etiopatogenia da periodontite ovina e para o desenvolvimento de medidas de controle da doença.

• Doenças de ovinos patologia ovinos periodontite doença periodontal anaeróbica histopatologia

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.- Rech R.R., Rissi D.R., Silva M.C., Inkelmann M.A. & Barros C.S.L. 2006. [Histomorphology of the Gasserian ganglion, carotid rete mirabile and pituitary gland in cattle: a study of 199 cases.] Histomorfologia do gânglio de Gasser, da rete mirabile carotídea e da hipófise de bovinos: estudo de 199 casos. Pesquisa Veterinária Brasileira 26(2):105-111. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The complex of heterogenous tissues formed by the Gasserian ganglia, carotid rete mirabile and pituitary gland (GRH) from 199 cattle were grossly and histologically evaluated. Twenty one of the GRH were from comfirmed cases of rabies, 19 were diagnosed as cases of meningoencephalitis caused by bovine herpesvirus-5 (BoHV-5), 11 were confirmed cases of malignant catarrhal fever (MCF), 7 had pituitary abscesses, 17 had lesions of hepatic encephalopathy (status spongiosus) attributable to chronic liver failure due to Senecio sp poisoning; and the remaining 124 GRH were from cattle which did not present neurological signs and died or were euthanatized due to various causes. No significant histologic changes were observed in the GRH from the 124 cattle which did not present neurological signs, in the GRH of the 17 cattle that had hepatic encephalopathy neither in the GRH of the 19 cattle diagnosed with BoHV-5 meningoencephalitis. Inflammatory changes were found in the Gasserian ganglia of 20 out of 21 cases of rabies and consisted of proliferation of sattelite cells, glial nodules and lymphoplasmacytic infiltrate; degenerative changes included central chromatolysis, neuronal vacuolation, and neuronal death with neuronophagia. Characteristic eosinophilic intracytoplasmatic inclusion (Negri) bodies were found in 19 out of 21 cases of rabies, neuritis of the fifth nerve in 11, and neurohypophysitis in 4 cases. The GRH from nine of the eleven cases of MCF had characteristic necrotizing arteritis affecting the arteries of the carotid rete mirabile. In seven cases pituitary abscesses were found; they were characterized by large aggregates of neutrophils admixed with cellular debris and surrounded by mononuclear cells and were walled by a fibrous capsule. Several incidental findings were observed equally in the 199 histologically examined GRH and consequently were non specific for any disease entity. These include cysts in the pituitary cleft, fibrin and neutrophilic aggregates in the cavernous sinus of the carotid rete mirabile, mildly increased numbers of sattelite cells around neurons of the Gasserian ganglia and occasional neuronal vacuolation and lipofuscinosis. It was concluded that the histological examination of the GRH is an important and reliable tool in the diagnosis of the main forms of encephalitis occurring in cattle in Brazil.

• Diseases of cattle diseases of the central nervous system Gasserian ganglion carotid rete mirabile pituitary gland neuropathology.

Abstract in Portuguese:

ABSTRACT.- Rech R.R., Rissi D.R., Silva M.C., Inkelmann M.A. & Barros C.S.L. 2006. [Histomorphology of the Gasserian ganglion, carotid rete mirabile and pituitary gland in cattle: a study of 199 cases.] Histomorfologia do gânglio de Gasser, da rete mirabile carotídea e da hipófise de bovinos: estudo de 199 casos. Pesquisa Veterinária Brasileira 26(2):105-111. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The complex of heterogenous tissues formed by the Gasserian ganglia, carotid rete mirabile and pituitary gland (GRH) from 199 cattle were grossly and histologically evaluated. Twenty one of the GRH were from comfirmed cases of rabies, 19 were diagnosed as cases of meningoencephalitis caused by bovine herpesvirus-5 (BoHV-5), 11 were confirmed cases of malignant catarrhal fever (MCF), 7 had pituitary abscesses, 17 had lesions of hepatic encephalopathy (status spongiosus) attributable to chronic liver failure due to Senecio sp poisoning; and the remaining 124 GRH were from cattle which did not present neurological signs and died or were euthanatized due to various causes. No significant histologic changes were observed in the GRH from the 124 cattle which did not present neurological signs, in the GRH of the 17 cattle that had hepatic encephalopathy neither in the GRH of the 19 cattle diagnosed with BoHV-5 meningoencephalitis. Inflammatory changes were found in the Gasserian ganglia of 20 out of 21 cases of rabies and consisted of proliferation of sattelite cells, glial nodules and lymphoplasmacytic infiltrate; degenerative changes included central chromatolysis, neuronal vacuolation, and neuronal death with neuronophagia. Characteristic eosinophilic intracytoplasmatic inclusion (Negri) bodies were found in 19 out of 21 cases of rabies, neuritis of the fifth nerve in 11, and neurohypophysitis in 4 cases. The GRH from nine of the eleven cases of MCF had characteristic necrotizing arteritis affecting the arteries of the carotid rete mirabile. In seven cases pituitary abscesses were found; they were characterized by large aggregates of neutrophils admixed with cellular debris and surrounded by mononuclear cells and were walled by a fibrous capsule. Several incidental findings were observed equally in the 199 histologically examined GRH and consequently were non specific for any disease entity. These include cysts in the pituitary cleft, fibrin and neutrophilic aggregates in the cavernous sinus of the carotid rete mirabile, mildly increased numbers of sattelite cells around neurons of the Gasserian ganglia and occasional neuronal vacuolation and lipofuscinosis. It was concluded that the histological examination of the GRH is an important and reliable tool in the diagnosis of the main forms of encephalitis occurring in cattle in Brazil.

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:

ABSTRACT.- Rissi D.R., Oliveira F.N., Rech R.R., Pierezan F., Lemos R.A.A. & Barros C.S.L. 2006. [Epidemiology, clinical signs and distribution of the encephalic lesions in cattle affected by meningoencephalitis caused by bovine herpesvirus-5.] Epidemiologia, sinais clínicos e distribuição das lesões encefálicas em bovinos afetados por meningoencefalite por herpesvírus bovino-5. Pesquisa Veterinária Brasileira 26(2):123-132. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Seven outbreaks and an isolated case of meningoencephalitis caused by bovine herpesvirus-5 (BoHV-5) in cattle in Rio Grande do Sul, Brazil, occurring in 2002-2004, are described. From a total population at risk of 1,359 cattle, 54 1-18-month-old calves from both sexes and several breeds were affected and 50 died spontaneously or were euthanatized while moribund. The highest frequency of cases was in recently weaned calves or calves submitted to other stressing factors. General rates of morbidity, mortality and lethality were respectively 3.97, 3.67 and 92.59%. Clinical courses varied from 3-10 days and included depression, nasal and ocular discharge, grinding of teeth, circling, blindness, fever, nistagmus, trembling, anorexia, dysphagia, drooling, incoordination, head pressing, rough hair coat, tachycardia, tachypnea, abdominal pain, melena, falls, recumbency, opisthotonus, convulsions and paddling. Nineteen calves were necropsied. Necropsy findings were characterized by hyperemia of leptomeninges, swollen rostral portions of the telencephalon, and flattening of frontal lobes gyri; frequently in these frontal areas there were segmental brown-yellow discoloration and softening (malacia) of the cortex. In cases with more protracted clinical courses there were extensive swelling, softening and hemorrhaging of the telencephalic frontal lobes. Microscopically, all affected cattle had a necrotizing non-suppurative meningoencephalitis with variable distribution among the 19 cases and among the various telencephalic regions of the same case. The severity of these changes were more marked, in decreasing order of intensity, in the telencephalic frontal cortex, basal ganglia (nuclei), thalamus, brain stem, parietal telencephalic cortex, occipital telencephalic cortex and cerebellum. Perivascular inflammatory infiltrate consisted predominantly of lymphocytes, plasm cells, and less frequently of neutrophils. Additional microscopic findings included variable degrees of gliosis, edema, neuronal necrosis in the telencephalic cortex characterized by shrinking and eosinophilia of perikaria and nuclear picnosis (red neuron); basophilic intranuclear inclusion bodies in astrocytes and neurons (21.05% of the cases); sattelitosis; and neuronophagia. The areas of softening in the cortical substance consisted of necrosis of the neuroctodermal elements with maintenance of mesenchymal structures (vessels and microglia), infiltrate of Gitter cells, and, in more severe cases, extensive hemorrhages. In chronic cases, only vascular structures and a few Gitter cells remained in the cortical area leaving a cavity between white matter and leptomeninges (residual lesion).

• Bovine herpesvirus-5 BoHV-5 encephalitis diseases of cattle viral diseases neuropathology.

Abstract in Portuguese:

ABSTRACT.- Rissi D.R., Oliveira F.N., Rech R.R., Pierezan F., Lemos R.A.A. & Barros C.S.L. 2006. [Epidemiology, clinical signs and distribution of the encephalic lesions in cattle affected by meningoencephalitis caused by bovine herpesvirus-5.] Epidemiologia, sinais clínicos e distribuição das lesões encefálicas em bovinos afetados por meningoencefalite por herpesvírus bovino-5. Pesquisa Veterinária Brasileira 26(2):123-132. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Seven outbreaks and an isolated case of meningoencephalitis caused by bovine herpesvirus-5 (BoHV-5) in cattle in Rio Grande do Sul, Brazil, occurring in 2002-2004, are described. From a total population at risk of 1,359 cattle, 54 1-18-month-old calves from both sexes and several breeds were affected and 50 died spontaneously or were euthanatized while moribund. The highest frequency of cases was in recently weaned calves or calves submitted to other stressing factors. General rates of morbidity, mortality and lethality were respectively 3.97, 3.67 and 92.59%. Clinical courses varied from 3-10 days and included depression, nasal and ocular discharge, grinding of teeth, circling, blindness, fever, nistagmus, trembling, anorexia, dysphagia, drooling, incoordination, head pressing, rough hair coat, tachycardia, tachypnea, abdominal pain, melena, falls, recumbency, opisthotonus, convulsions and paddling. Nineteen calves were necropsied. Necropsy findings were characterized by hyperemia of leptomeninges, swollen rostral portions of the telencephalon, and flattening of frontal lobes gyri; frequently in these frontal areas there were segmental brown-yellow discoloration and softening (malacia) of the cortex. In cases with more protracted clinical courses there were extensive swelling, softening and hemorrhaging of the telencephalic frontal lobes. Microscopically, all affected cattle had a necrotizing non-suppurative meningoencephalitis with variable distribution among the 19 cases and among the various telencephalic regions of the same case. The severity of these changes were more marked, in decreasing order of intensity, in the telencephalic frontal cortex, basal ganglia (nuclei), thalamus, brain stem, parietal telencephalic cortex, occipital telencephalic cortex and cerebellum. Perivascular inflammatory infiltrate consisted predominantly of lymphocytes, plasm cells, and less frequently of neutrophils. Additional microscopic findings included variable degrees of gliosis, edema, neuronal necrosis in the telencephalic cortex characterized by shrinking and eosinophilia of perikaria and nuclear picnosis (red neuron); basophilic intranuclear inclusion bodies in astrocytes and neurons (21.05% of the cases); sattelitosis; and neuronophagia. The areas of softening in the cortical substance consisted of necrosis of the neuroctodermal elements with maintenance of mesenchymal structures (vessels and microglia), infiltrate of Gitter cells, and, in more severe cases, extensive hemorrhages. In chronic cases, only vascular structures and a few Gitter cells remained in the cortical area leaving a cavity between white matter and leptomeninges (residual lesion).

Abstract in English:

Rozza D.B., Raymundo D.L., Corrêa A.M.R., Seitz A.L., Driemeier D. & Colodel E.M. 2006. [Spontaneous Baccharis coridifolia (Compositae) poisoning in sheep.] Intoxicação espontânea por Baccharis coridifolia (Compositae) em ovinos. Pesquisa Veterinária Brasileira 26(1):21-25. Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: moleta@terra.com.br An outbreak of Baccharis coridifolia (Compositae) poisoning in sheep is reported, which occurred in November 2004 in the county of Caxias do Sul, Rio Grande do Sul (RS), southern Brazil. From a herd of 212 sheep, coming from a Baccharis coridifolia free area, in the county of Jaguarão, RS, 35 sheep died until 5 days after the arrival in the new area where the plant was found with abundance. The clinical signs began 8 hours after introduction of the animals into the new pasture and included apathy, anorexia, abdominal retraction or mild distension, weakness of hind limbs, dry feces, sternal ou lateral decumbency, struggling movements, coma and death. Clinical evolution was from 5 to 48 hours. Other sheep that were already before on the pasture were not affected. Main necropsy findings were in the gastrointestinal tube, with wall and serosal oedema, mainly in the reticulo-ruminal fold and of the abomasum, reddening and detachment of the mucosa of forestomachs, and intense hemorrhage in the submucosa. Histopathological findings were degeneration and necrosis of the epithelium of the forestomachs with polymorphonuclear infiltration associated with bacterial colonies, congestion, hemorrhage and oedema, and lymphoid tissue necrosis.

• Poisonous plants Baccharis coridifolia Compositae plant poisoning diseases of sheep pathology.

Abstract in Portuguese:

Rozza D.B., Raymundo D.L., Corrêa A.M.R., Seitz A.L., Driemeier D. & Colodel E.M. 2006. [Spontaneous Baccharis coridifolia (Compositae) poisoning in sheep.] Intoxicação espontânea por Baccharis coridifolia (Compositae) em ovinos. Pesquisa Veterinária Brasileira 26(1):21-25. Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: moleta@terra.com.br An outbreak of Baccharis coridifolia (Compositae) poisoning in sheep is reported, which occurred in November 2004 in the county of Caxias do Sul, Rio Grande do Sul (RS), southern Brazil. From a herd of 212 sheep, coming from a Baccharis coridifolia free area, in the county of Jaguarão, RS, 35 sheep died until 5 days after the arrival in the new area where the plant was found with abundance. The clinical signs began 8 hours after introduction of the animals into the new pasture and included apathy, anorexia, abdominal retraction or mild distension, weakness of hind limbs, dry feces, sternal ou lateral decumbency, struggling movements, coma and death. Clinical evolution was from 5 to 48 hours. Other sheep that were already before on the pasture were not affected. Main necropsy findings were in the gastrointestinal tube, with wall and serosal oedema, mainly in the reticulo-ruminal fold and of the abomasum, reddening and detachment of the mucosa of forestomachs, and intense hemorrhage in the submucosa. Histopathological findings were degeneration and necrosis of the epithelium of the forestomachs with polymorphonuclear infiltration associated with bacterial colonies, congestion, hemorrhage and oedema, and lymphoid tissue necrosis.

Abstract in English:

Langohr I.M., Gava A. & Barros C.S.L. 2005. [Poisoning in cattle by Baccharidastrum triplinervium (Asteraceae).] Intoxicação por Baccharidastrum triplinervium (Asteraceae) em bovinos. Pesquisa Veterinária Brasileira 25(4):235-238. Animal Disease Diagnostic Laboratory, Purdue University, 406 South University, West Lafayette, IN 47907, Estados Unidos. E-mail: ilangohr@purdue.edu An outbreak of poisoning by Baccharidastrum triplinervium in cattle from Paraná, Brazil, is described. The disease occurred during a severe drought in early summer. The onset of clinical signs was two days after 50 cows and 8 heifers had been introduced into a pasture with high density of B. triplinervium that showed signs of having been consumed by the animals. Fifteen animals (9 cows and 6 heifers) got sick. Of these 15, two cows and four heifers died after a clinical course of 12-60 hours. Clinical signs included depression, ruminal atony, moderate bloat, marked dehydration, mild diarrhea and anorexia. The animals were restless, laying down and getting up constantly, remaining progressively longer periods in sternal recumbency. Once in that position, the animals had an extended head or the head turned to one of the sides of the body, and were groaning. Additionally, the cows had an abrupt fall in milk yield. The remaining affected cattle presented milder clinical signs and were partially back to their feed on the day following the onset of the clinical signs. The milk production was back to normal values within one week. The main gross lesions observed in two necropsied cows were in the forestomachs and abomasum, consisting of edema of the ruminal wall, as well as of diffuse reddening of the mucosae of the rumen, reticulum, abomasum and of some of the omasal folds. The main histological lesions included multifocal ballooning degeneration and necrosis of the lining epithelium of the rumen, associated with neutrophilic infiltrate. The diagnosis was based on the epidemiological data and on the experimental reproduction of the disease by force-feeding 3 bovine with the aeral fresh parts (20 and 30g/kg) of B. triplinervium. Chemical analysis of dried material from B. triplinervium harvested at the site of the outbreak was negative for macrocyclic trichothecenes.

• Poisonous plants Baccharidastrum triplinervium Asteraceae plant poisoning diseases of cattle pathology.

Abstract in Portuguese:

Langohr I.M., Gava A. & Barros C.S.L. 2005. [Poisoning in cattle by Baccharidastrum triplinervium (Asteraceae).] Intoxicação por Baccharidastrum triplinervium (Asteraceae) em bovinos. Pesquisa Veterinária Brasileira 25(4):235-238. Animal Disease Diagnostic Laboratory, Purdue University, 406 South University, West Lafayette, IN 47907, Estados Unidos. E-mail: ilangohr@purdue.edu An outbreak of poisoning by Baccharidastrum triplinervium in cattle from Paraná, Brazil, is described. The disease occurred during a severe drought in early summer. The onset of clinical signs was two days after 50 cows and 8 heifers had been introduced into a pasture with high density of B. triplinervium that showed signs of having been consumed by the animals. Fifteen animals (9 cows and 6 heifers) got sick. Of these 15, two cows and four heifers died after a clinical course of 12-60 hours. Clinical signs included depression, ruminal atony, moderate bloat, marked dehydration, mild diarrhea and anorexia. The animals were restless, laying down and getting up constantly, remaining progressively longer periods in sternal recumbency. Once in that position, the animals had an extended head or the head turned to one of the sides of the body, and were groaning. Additionally, the cows had an abrupt fall in milk yield. The remaining affected cattle presented milder clinical signs and were partially back to their feed on the day following the onset of the clinical signs. The milk production was back to normal values within one week. The main gross lesions observed in two necropsied cows were in the forestomachs and abomasum, consisting of edema of the ruminal wall, as well as of diffuse reddening of the mucosae of the rumen, reticulum, abomasum and of some of the omasal folds. The main histological lesions included multifocal ballooning degeneration and necrosis of the lining epithelium of the rumen, associated with neutrophilic infiltrate. The diagnosis was based on the epidemiological data and on the experimental reproduction of the disease by force-feeding 3 bovine with the aeral fresh parts (20 and 30g/kg) of B. triplinervium. Chemical analysis of dried material from B. triplinervium harvested at the site of the outbreak was negative for macrocyclic trichothecenes.

Abstract in English:

Rech R.R., Schild A.L., Driemeier D., Garmatz S.L., Oliveira F.N., Riet-Correa F. & Barros C.S.L. 2005. [Malignant catarrhal fever in cattle in Rio Grande do Sul, Brazil: Epidemiology, clinical signs and pathology.] Febre catarral maligna em bovinos no Rio Grande do Sul: epidemiologia, sinais clínicos e patologia. Pesquisa Veterinária Brasileira 25(2):97-105. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The epidemiology, clinical signs, necropsy and histopathological findings in cases of malignant catarrhal fever (MCF) occurring in cattle from 15 farms in Rio Grande do Sul, Brazil, from 1973 to 2003, are described. In 9 instances (60%) the disease occurred as sporadic cases affecting 1-3 cattle whereas in six farms (40%) MCF occurred as epizootics involving several cattle in each affected herd. Morbidity rates ranged from 2.4% to 20% and lethality rates were 83.3% and 100%. Cattle of all ages and both sexes were affected. Where the information was available (9 farms) sheep were in contact with affected cattle and cases of MCF occurred more frequently in spring and summer. Clinical courses were acute or subacute and clinical signs included fever, nasal and ocular discharges, conjunctivitis, drooling, hematuria, necrosis and blunting of buccal papillae, enlargement of lymph nodes, diarrhea and neurological disturbances. Necropsy findings included opaque corneas, reddening, erosions and ulcerations in several mucous membranes of the alimentary, respiratory and urogenital tracts, and the conjunctiva; enlargement and haemorrhage of lymph nodes and multiple white foci in the renal cortices and in the hepatic portal triads. Crustous dermatitis was observed in some cases. Main histopathological findings included vasculitis, necrosis of the surface epithelia and accumulation of inflammatory cells in several organs. Vasculitis were associated with fibrinoid necrosis of the medial layer of arteries and inflammatory cells included lymphoblasts, lymphocytes, plasma cells and macrophages.

• Infectious diseases epidemiology viral diseases diseases of cattle pathology.

Abstract in Portuguese:

Rech R.R., Schild A.L., Driemeier D., Garmatz S.L., Oliveira F.N., Riet-Correa F. & Barros C.S.L. 2005. [Malignant catarrhal fever in cattle in Rio Grande do Sul, Brazil: Epidemiology, clinical signs and pathology.] Febre catarral maligna em bovinos no Rio Grande do Sul: epidemiologia, sinais clínicos e patologia. Pesquisa Veterinária Brasileira 25(2):97-105. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br The epidemiology, clinical signs, necropsy and histopathological findings in cases of malignant catarrhal fever (MCF) occurring in cattle from 15 farms in Rio Grande do Sul, Brazil, from 1973 to 2003, are described. In 9 instances (60%) the disease occurred as sporadic cases affecting 1-3 cattle whereas in six farms (40%) MCF occurred as epizootics involving several cattle in each affected herd. Morbidity rates ranged from 2.4% to 20% and lethality rates were 83.3% and 100%. Cattle of all ages and both sexes were affected. Where the information was available (9 farms) sheep were in contact with affected cattle and cases of MCF occurred more frequently in spring and summer. Clinical courses were acute or subacute and clinical signs included fever, nasal and ocular discharges, conjunctivitis, drooling, hematuria, necrosis and blunting of buccal papillae, enlargement of lymph nodes, diarrhea and neurological disturbances. Necropsy findings included opaque corneas, reddening, erosions and ulcerations in several mucous membranes of the alimentary, respiratory and urogenital tracts, and the conjunctiva; enlargement and haemorrhage of lymph nodes and multiple white foci in the renal cortices and in the hepatic portal triads. Crustous dermatitis was observed in some cases. Main histopathological findings included vasculitis, necrosis of the surface epithelia and accumulation of inflammatory cells in several organs. Vasculitis were associated with fibrinoid necrosis of the medial layer of arteries and inflammatory cells included lymphoblasts, lymphocytes, plasma cells and macrophages.

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:

Zlotowski P., Corrêa A. M. R., Rozza D. B., Driemeier D., Mallmann C. A. & Migliavacca F.A. 2004. [Swine aflatoxicosis outbreak in the state of Rio Grande do Sul, Brazil.] Surto de aflatoxicose em suínos no Estado do Rio Grande do Sul. Pesquisa Veterinária Brasileira 24(4):207-210. Setor de Patologia Veterinária, Depto Patologia Clínica Veterinária, Faculdade de Veteri-nária, UFRGS, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@vortex.ufrgs.br An outbreak of aflatoxicosis in a swine herd, which occurred in fall 2004 in the county of Sentinela do Sul, RS, is described. The corn, which contained the micotoxin and has been used to feed the animals, was produced and processed on the farm. Seven sows and 8 growing pigs died, and 2 cases of abortion were reported. The clinical signs observed were apathy, anorexia, icterus, yellowish urine stained with blood, and photosensitization. Gamma glutamyltransferase and total bilirubin were elevated in the 4 pigs on which post-mortem examination was done. The main macroscopic findings were generalized icterus, an orange-yellow liver, edema of the gall bladder wall and yellowish effusion in the abdominal and pericardial cavities. The most important microscopic changes were found in the liver and included tumefaction, degeneration and individual necrosis of the parenchyme, with ductal proliferation and cholestasis. The diagnosis was based on the clinical signs, macroscopic and histological findings and on the high levels of B1 aflatoxin found in the corn and ration.

• Mycotoxins aflatoxicosis hepatotoxicosis swine pathology.

Abstract in Portuguese:

Zlotowski P., Corrêa A. M. R., Rozza D. B., Driemeier D., Mallmann C. A. & Migliavacca F.A. 2004. [Swine aflatoxicosis outbreak in the state of Rio Grande do Sul, Brazil.] Surto de aflatoxicose em suínos no Estado do Rio Grande do Sul. Pesquisa Veterinária Brasileira 24(4):207-210. Setor de Patologia Veterinária, Depto Patologia Clínica Veterinária, Faculdade de Veteri-nária, UFRGS, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@vortex.ufrgs.br An outbreak of aflatoxicosis in a swine herd, which occurred in fall 2004 in the county of Sentinela do Sul, RS, is described. The corn, which contained the micotoxin and has been used to feed the animals, was produced and processed on the farm. Seven sows and 8 growing pigs died, and 2 cases of abortion were reported. The clinical signs observed were apathy, anorexia, icterus, yellowish urine stained with blood, and photosensitization. Gamma glutamyltransferase and total bilirubin were elevated in the 4 pigs on which post-mortem examination was done. The main macroscopic findings were generalized icterus, an orange-yellow liver, edema of the gall bladder wall and yellowish effusion in the abdominal and pericardial cavities. The most important microscopic changes were found in the liver and included tumefaction, degeneration and individual necrosis of the parenchyme, with ductal proliferation and cholestasis. The diagnosis was based on the clinical signs, macroscopic and histological findings and on the high levels of B1 aflatoxin found in the corn and ration.