PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Tokarnia C.H. & Peixoto P.V. 2005. [The importance of snake bites as cause of cattle death in Brazil.] A importância dos acidentes ofídicos como causa de mortes em bovinos no Brasil. Pesquisa Veterinária Brasileira 26(2):55-68. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23890-000, Brazil. E-mail: tokarnia@ufrrj.br A review of the literature shows that opinions on the importance of snake bites as cause of cattle death in Brazil are divergent among veterinarians; some think they are of no importance or of only minor significance, others are of the opinion that snake bites are frequent. However, the literature only reports two confirmed fatal cases by Bothrops and none by Crotalus in cattle in the country. A questionnaire which was submitted for appraisal to veterinary pathologists and clinicians in various States of Brazil, revealed only suspected cases of fatal accidents by snakes in cattle. During our field and laboratory diagnostic work we never made a diagnosis of a snake bite accident. Many “diagnoses” have apparently been made at a distance from where the animals died, without clinical and post-mortem examination, nor histological studies. By this way, the great majority of cases seems to be only supposition. In Brazil there are only few snakes of the genus Bothrops theoretically able to produce sufficient amounts of venom to kill an adult bovine. Nevertheless, in experiments, only Bothrops alternatus was able to cause the death of just one out of three bovines bitten, and this animal only weighed 279 kg. Snakes of the genus Crotalus can produce sufficient amounts of venom to kill an adult bovine; however it is known, that snakes of the genus Crotalus as well as of Bothrops generally inoculate only a part of their venom. These considerations indicate that the deaths suspected to have been caused by snake bites in cattle in Brazil have to be studied more thoroughly. A diagnosis can only be confirmed by establishing the precise clinical and pathological picture. Our current opinion is that fatal snake bites are much less frequent in cattle than often believed, and that their importance is generally much exaggerated.

• Snake bites snakes Crotalus spp Bothrops spp cattle.

Abstract in Portuguese:

ABSTRACT.- Tokarnia C.H. & Peixoto P.V. 2005. [The importance of snake bites as cause of cattle death in Brazil.] A importância dos acidentes ofídicos como causa de mortes em bovinos no Brasil. Pesquisa Veterinária Brasileira 26(2):55-68. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23890-000, Brazil. E-mail: tokarnia@ufrrj.br A review of the literature shows that opinions on the importance of snake bites as cause of cattle death in Brazil are divergent among veterinarians; some think they are of no importance or of only minor significance, others are of the opinion that snake bites are frequent. However, the literature only reports two confirmed fatal cases by Bothrops and none by Crotalus in cattle in the country. A questionnaire which was submitted for appraisal to veterinary pathologists and clinicians in various States of Brazil, revealed only suspected cases of fatal accidents by snakes in cattle. During our field and laboratory diagnostic work we never made a diagnosis of a snake bite accident. Many “diagnoses” have apparently been made at a distance from where the animals died, without clinical and post-mortem examination, nor histological studies. By this way, the great majority of cases seems to be only supposition. In Brazil there are only few snakes of the genus Bothrops theoretically able to produce sufficient amounts of venom to kill an adult bovine. Nevertheless, in experiments, only Bothrops alternatus was able to cause the death of just one out of three bovines bitten, and this animal only weighed 279 kg. Snakes of the genus Crotalus can produce sufficient amounts of venom to kill an adult bovine; however it is known, that snakes of the genus Crotalus as well as of Bothrops generally inoculate only a part of their venom. These considerations indicate that the deaths suspected to have been caused by snake bites in cattle in Brazil have to be studied more thoroughly. A diagnosis can only be confirmed by establishing the precise clinical and pathological picture. Our current opinion is that fatal snake bites are much less frequent in cattle than often believed, and that their importance is generally much exaggerated.

Abstract in English:

ABSTRACT.- D’Andrea L.A.Z., Sartor I.F., Madruga C.R., Freitas S.B.Z., Kroll L.B. & Kronka S.N. 2005. [Immunological condition of cattle in Holstein and Nelore breed in regard to Babesia bovis and B. bigemina in two regions of the State of São Paulo.] Condição imunológica de bovinos das raças Holandesa e Nelore frente a Babesia bovis e B. bigemina em duas regiões do Estado de São Paulo. Pesquisa Veterinária Brasileira 26(2):74-78.. Seção de Biologia Médica do Instituto Adolfo Lutz, Laboratório Regional de Presidente Prudente, Av. Cel José Soares Marcondes 2357, Presidente Prudente, SP 19013-050, Brazil. E-mail: zampieri@ial.sp.gov.br The immunological reply of a population to an infectious agent can vary between races and handling of this population. Regional research becomes important, in order to know the interrelation between the agent and its host. In this way, the occurrence of immunoglobulins of class G, anti-Babesia bovis and anti-Babesia bigemina in the Nelore (Bos indicus) and Hostein breed (Bos taurus), was investigated in two regions of the State of São Paulo, 300 km distant from each other. For the indirect method of ELISA, 1,161 bovine serum samples were tested. The medium frequencies of antibodies showed that in the two regions exists an enzootic stability for B. bovis in both breeds studied; even so there was a tendency of marginal area for the Nelore breed in one of the regions. Regarding B. bigemina, in both regions exists enzootic stability for the Hostein and enzootic instability for the Nelore breed. Therefore, acute cases of the disease or specific outbreaks by B. bigemina infection in the Nelore breed may occur in these regions.

• Babesia bovis Babesia bigemina ELISA cattle immunological condition.

Abstract in Portuguese:

ABSTRACT.- D’Andrea L.A.Z., Sartor I.F., Madruga C.R., Freitas S.B.Z., Kroll L.B. & Kronka S.N. 2005. [Immunological condition of cattle in Holstein and Nelore breed in regard to Babesia bovis and B. bigemina in two regions of the State of São Paulo.] Condição imunológica de bovinos das raças Holandesa e Nelore frente a Babesia bovis e B. bigemina em duas regiões do Estado de São Paulo. Pesquisa Veterinária Brasileira 26(2):74-78.. Seção de Biologia Médica do Instituto Adolfo Lutz, Laboratório Regional de Presidente Prudente, Av. Cel José Soares Marcondes 2357, Presidente Prudente, SP 19013-050, Brazil. E-mail: zampieri@ial.sp.gov.br The immunological reply of a population to an infectious agent can vary between races and handling of this population. Regional research becomes important, in order to know the interrelation between the agent and its host. In this way, the occurrence of immunoglobulins of class G, anti-Babesia bovis and anti-Babesia bigemina in the Nelore (Bos indicus) and Hostein breed (Bos taurus), was investigated in two regions of the State of São Paulo, 300 km distant from each other. For the indirect method of ELISA, 1,161 bovine serum samples were tested. The medium frequencies of antibodies showed that in the two regions exists an enzootic stability for B. bovis in both breeds studied; even so there was a tendency of marginal area for the Nelore breed in one of the regions. Regarding B. bigemina, in both regions exists enzootic stability for the Hostein and enzootic instability for the Nelore breed. Therefore, acute cases of the disease or specific outbreaks by B. bigemina infection in the Nelore breed may occur in these regions.

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.- Coimbra H.S., Fernandes C.G., Soares M.P., Meireles M.C.A., Radamés R. & Schuch L.F.D. 2006. [Equine monocytic Ehrlichiosis in Rio Grande do Sul: clinical, pathological and epidemiological aspects.] Ehrlichiose monocítica eqüina no Rio Grande do Sul: aspectos clínicos, anátomo-patológicos e epidemiológicos. Pesquisa Veterinária Brasileira 26(2):97-101. Laboratório de Doenças Infecciosas, Faculdade de Veterinária, Universidade Federal de Pelotas, Campus Universitário, Pelotas, RS 96010-900, Brazil. E-mail: bitoxu@ig.com.br A spontaneous outbreak of equine monocytic Ehrlichiosis (EME) is described. The disease occurred from November 2001 to February 2002 on a farm in the municipality of Arroio Grande, located at the western edge of the Mirim Lake, state of Rio Grande do Sul. Out of 50 horses 13 were affected and 6 died. The morbidity was 26% and the mortality 46.1%. The affected horses were 1-5 years old. The most important clinical sign was a profuse acute diarrhea. At necropsy of a horse that died with clinical signs of the disease, the main alterations were characterized by hemorrhagic areas of the mucosa of the large intestine with liquid contents, and congested and hemorrhagic areas alternating with normal areas as well as nodules with purulent secretion in the mucosa of the small intestine. The histological changes were characterized by moderate mononuclear infiltration of the mucosa, characterizing a lympho-histiocytic enteritis with predominance of macrophages. In the jejunum and ileum, related to the invagination of crypts and villi, a granulomatous enteritis was observed. To confirm the diagnosis of infection by Neorickettsia (Ehrlichia) risticii, blood samples of seven affected horses were taken and a polimerase chain reaction (PCR) was performed. Three tested blood samples were positive (42.8%) with observation of a band of 529pb characteristic of N. risticii.

• Neorickettsia (Ehrlichia) risticii equine monocytic Ehrlichiosis.

Abstract in Portuguese:

ABSTRACT.- Coimbra H.S., Fernandes C.G., Soares M.P., Meireles M.C.A., Radamés R. & Schuch L.F.D. 2006. [Equine monocytic Ehrlichiosis in Rio Grande do Sul: clinical, pathological and epidemiological aspects.] Ehrlichiose monocítica eqüina no Rio Grande do Sul: aspectos clínicos, anátomo-patológicos e epidemiológicos. Pesquisa Veterinária Brasileira 26(2):97-101. Laboratório de Doenças Infecciosas, Faculdade de Veterinária, Universidade Federal de Pelotas, Campus Universitário, Pelotas, RS 96010-900, Brazil. E-mail: bitoxu@ig.com.br A spontaneous outbreak of equine monocytic Ehrlichiosis (EME) is described. The disease occurred from November 2001 to February 2002 on a farm in the municipality of Arroio Grande, located at the western edge of the Mirim Lake, state of Rio Grande do Sul. Out of 50 horses 13 were affected and 6 died. The morbidity was 26% and the mortality 46.1%. The affected horses were 1-5 years old. The most important clinical sign was a profuse acute diarrhea. At necropsy of a horse that died with clinical signs of the disease, the main alterations were characterized by hemorrhagic areas of the mucosa of the large intestine with liquid contents, and congested and hemorrhagic areas alternating with normal areas as well as nodules with purulent secretion in the mucosa of the small intestine. The histological changes were characterized by moderate mononuclear infiltration of the mucosa, characterizing a lympho-histiocytic enteritis with predominance of macrophages. In the jejunum and ileum, related to the invagination of crypts and villi, a granulomatous enteritis was observed. To confirm the diagnosis of infection by Neorickettsia (Ehrlichia) risticii, blood samples of seven affected horses were taken and a polimerase chain reaction (PCR) was performed. Three tested blood samples were positive (42.8%) with observation of a band of 529pb characteristic of N. risticii.

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:

ABSTRACT.- Costa M.M., Silva M.S., Spricigo D.A., Witt N.M., Marchioro S.B., Kolling L. & Vargas A.P.C. 2006. [Epidemiology, molecular characterization and resistance to antimicrobials of Escherichia coli isolated from South-Brazilian pig herds.] Caracterização epidemiológica, molecular e perfil de resistência aos antimicrobianos de Escherichia coli isoladas de criatórios suínos do Sul do Brasil. Pesquisa Veterinária Brasileira 26(1):5-8. Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: agueda@ccr.ufsm.br Colibacillosis is an enteric disease with a major impact to the swine industry and is caused by enterotoxigenic strains of Escherichia coli. Forty clinical isolates from pigs with diarrhea and 13 environmental isolates were analysed regarding their genotypic profile, genetic relationship and antibiotic resistance. The most prevalent gene was Stb, identified in 50% of the isolates from clinical cases, and Sta and Lt were detected in 35% of them. Among the adesine factors investigated, F18 was found in 27.5% of the E. coli strains. The ERIC-PCR technique used for epidemiological characterization of the isolates did not show the expected discriminatory power. However, the test allowed separation of the isolates in groups, but did not evidence groups related to virulence factors. In the susceptibility test, the highest values for resistance were to tetracycline, in 88.6%. The index of multiple resistance to antimicrobials varied from 0 to 0.69.

• Escherichia coli genotypic profile resistance.

Abstract in Portuguese:

ABSTRACT.- Costa M.M., Silva M.S., Spricigo D.A., Witt N.M., Marchioro S.B., Kolling L. & Vargas A.P.C. 2006. [Epidemiology, molecular characterization and resistance to antimicrobials of Escherichia coli isolated from South-Brazilian pig herds.] Caracterização epidemiológica, molecular e perfil de resistência aos antimicrobianos de Escherichia coli isoladas de criatórios suínos do Sul do Brasil. Pesquisa Veterinária Brasileira 26(1):5-8. Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: agueda@ccr.ufsm.br Colibacillosis is an enteric disease with a major impact to the swine industry and is caused by enterotoxigenic strains of Escherichia coli. Forty clinical isolates from pigs with diarrhea and 13 environmental isolates were analysed regarding their genotypic profile, genetic relationship and antibiotic resistance. The most prevalent gene was Stb, identified in 50% of the isolates from clinical cases, and Sta and Lt were detected in 35% of them. Among the adesine factors investigated, F18 was found in 27.5% of the E. coli strains. The ERIC-PCR technique used for epidemiological characterization of the isolates did not show the expected discriminatory power. However, the test allowed separation of the isolates in groups, but did not evidence groups related to virulence factors. In the susceptibility test, the highest values for resistance were to tetracycline, in 88.6%. The index of multiple resistance to antimicrobials varied from 0 to 0.69.

Abstract in English:

Corrêa A.M.R., Pescador C.A., Schmitz M., Zlotowski P., Rozza D.B., Oliveira E.C., Barcellos D.E. & Driemeier D. 2006. [Clinical and pathological aspects of swine circovirosis in Rio Grande do Sul, southern Brazil.] Aspectos clínico-patológicos associados à circovirose suína no Rio Grande do Sul. Pesquisa Veterinária Brasileira 26(1):9-13. Setor de Patologia Veterinária, Faculdade de Veterinária, UFRGS, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br A total of 97 pigs, which had presented wasting, lymphadenomegaly, respiratory distress and pale or icteric mucosa, was necropsied over a 6-month period. Macroscopic lesions were characterized mostly by enlarged lymph nodes, non collapsed and round edged lungs with cranio-ventral areas of consolidation and interlobular edema. Kidneys had increased size, were pale, and presented numerous scattered white spots projecting from surface to the cortical area. Some kidneys also showed small red spots similar to petechial hemorrhage over the cortex. Main microscopic lesions were lympho-histiocytic infiltration in lymph nodes, lungs, and kidneys. Immunohistochemical probing with polyclonal antisera to type II swine circovirus stained positively in 50 out of the 56 cases tested (89.2%).

• Circovirus PMWS PCV2 immunohistochemistry swine.

Abstract in Portuguese:

Corrêa A.M.R., Pescador C.A., Schmitz M., Zlotowski P., Rozza D.B., Oliveira E.C., Barcellos D.E. & Driemeier D. 2006. [Clinical and pathological aspects of swine circovirosis in Rio Grande do Sul, southern Brazil.] Aspectos clínico-patológicos associados à circovirose suína no Rio Grande do Sul. Pesquisa Veterinária Brasileira 26(1):9-13. Setor de Patologia Veterinária, Faculdade de Veterinária, UFRGS, Av. Bento Gonçalves 9090, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@ufrgs.br A total of 97 pigs, which had presented wasting, lymphadenomegaly, respiratory distress and pale or icteric mucosa, was necropsied over a 6-month period. Macroscopic lesions were characterized mostly by enlarged lymph nodes, non collapsed and round edged lungs with cranio-ventral areas of consolidation and interlobular edema. Kidneys had increased size, were pale, and presented numerous scattered white spots projecting from surface to the cortical area. Some kidneys also showed small red spots similar to petechial hemorrhage over the cortex. Main microscopic lesions were lympho-histiocytic infiltration in lymph nodes, lungs, and kidneys. Immunohistochemical probing with polyclonal antisera to type II swine circovirus stained positively in 50 out of the 56 cases tested (89.2%).

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.