PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Nogueira A.P.A., Souza R.I.C., Santos B.S., Pinto A.P., Ribas N.L.K.S., Lemos R.A.A. & Sant’Ana F.J.F. 2010. [Experimentally amprolium-induced polio-encephalomalacia in cattle.] Polioencefalomalacia experimental induzida por amprólio em bovinos. Pesquisa Veterinária Brasileira 30(8):631-636. Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS 79070-900, Brazil. E-mail: santanafjf@yahoo.com In order to establish an experimental model for the study of the etiology, pathology, and pathogenesis of polioencephalomalacia (PEM) in cattle, the condition was induced into four steers by oral administration of amprolium at daily doses of 500 and 350mg per kg of body weight respectively for 22 and 26-28 days. All steers died spontaneously or were euthanized in extremis after being sick for 4-7 days. Three steers that received the drug at 1,000mg/kg and two that received 500mg/kg died spontaneously with acute or subacute clinical signs and without lesions and signs of PEM. In those steers in which PEM was reproduced, the neurological signs included marked apathy, incoordination, sawhorse stance, occasional falls, hyperexcitability, muscle tremors, blindness, grinding of teeth, strabismus, nystagmus, mydriasis, opisthotonus, and lateral recumbency with paddling movements. Main gross lesions were restricted to the brain and included swelling, flattening, softening and yellow discoloration of the cerebral circumvolutions. Histologically, there was segmental laminar neuronal necrosis (red neurons) associated with edema, swelling of endothelial cells, cleavage of laminar neuronal layers or between gray and white matter and moderate to severe infiltration by foamy macrophages (gitter cells). These changes were more marked in the frontal, parietal and occipital telencephalic lobes. Additionally, similar and moderate lesions were detected in the midbrain and hippocampus. Neuronal necrosis and edema affected uniformly the neurons layers of the grey matter of the frontal, parietal and occipital lobes. This experimental model of PEM with oral administration of amprolium may be useful for the study in cattle, as previously observed in sheep.

• Amprolium polioencephalomalacia amprólio polioencefalomalacia

Abstract in Portuguese:

RESUMO.- Nogueira A.P.A., Souza R.I.C., Santos B.S., Pinto A.P., Ribas N.L.K.S., Lemos R.A.A. & Sant’Ana F.J.F. 2010. [Experimentally amprolium-induced polio-encephalomalacia in cattle.] Polioencefalomalacia experimental induzida por amprólio em bovinos. Pesquisa Veterinária Brasileira 30(8):631-636. Faculdade de Medicina Veterinária e Zootecnia, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS 79070-900, Brazil. E-mail: santanafjf@yahoo.com Para estabelecer um modelo experimental para o estudo da etiologia, patologia e patogênese da polioencefalomalacia (PEM) em bovinos, a condição foi induzida em quatro novilhos pela administração oral de amprólio nas doses diárias de 500 e 350mg/kg de peso vivo, respectivamente por 22 e 26-28 dias. Todos os bovinos morreram espontaneamente ou foram eutanasiados in extremis após um curso clínico de 4-7 dias. Três bovinos que receberam 1.000mg/kg de amprólio e dois que receberam 500mg/kg morreram espontaneamente com quadro clínico agudo a subagudo sem desenvolverem sinais e lesões de PEM. Nos novilhos que PEM foi reproduzida, os sinais neurológicos incluíram marcada apatia, incoordenação, posição de cavalete, quedas ocasionais, hiperexcitabilidade, tremores musculares, cegueira, bruxismo, estrabismo, nistagmo, midríase, opistótono, decúbito lateral e movimentos de pedalagem. Os principais achados de necropsia eram restritos ao encéfalo e consistiam de tumefação, achatamento, amolecimento e amarelamento das circunvoluções cerebrais. Histologicamente, havia necrose neuronal segmentar e laminar (neurônios vermelhos) associada a edema, tumefação endotelial, separação das lâminas de neurônios do córtex telencefálico ou entre as substâncias cinzenta e branca e infiltração moderada a acentuada de macrófagos espumosos. Essas alterações eram mais acentuadas nos lobos telencefálicos frontal, parietal e occipital. Adicionalmente, lesões similares e moderadas foram detectadas no mesencéfalo e hipocampo. A necrose neuronal e o edema afetaram uniformemente as camadas de neurônios da substância cinzenta dos lobos telencefálicos frontal, parietal e occipital. Esse modelo experimental de PEM com administração oral de amprólio parece ser útil para o estudo da doença em bovinos, conforme observado anteriormente em ovinos.

Abstract in English:

ABSTRACT.- Pimentel L.A., Oliveira D.M., Galiza G.J.N., Dantas A.F.M., Uzal F. & Riet-Correa F. 2010. Focal symmetrical encephalomalacia in sheep. Pesquisa Veterinária Brasileira 30(5):423-427. Setor de Patologia Veterinária, Hospital Veterinário, CSTR, Campus de Patos, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br Focal symmetrical encephalomalacia (FSE) is the most prominent lesion seen in the chronic form of enterotoxemia by Clostridium perfringens type D. This paper reports FSE in sheep in Brazil. Six deaths occurred within a seven days period in a flock of 70, four to 30-month-old Santa Inês sheep in the state of Paraíba in the Brazilian semiarid. The flock was grazing a paddock of irrigated sprouting Cynodon dactylon (Tifton grass), and supplemented, ad libitum, with a concentrate of soybean, corn and wheat. Nervous signs included blindness and recumbence. A 19 month-old sheep was examined clinically and necropsied after a clinical course of three days. Gross lesions were herniation of the cerebellar vermis and multifocal, bilateral, symmetric brownish areas in the internal capsule, thalamus and cerebellar peduncles. Histologic lesions were multifocal, bilateral malacia with some neutrophils, swelling of blood vessels endothelium, perivascular edema, and hemorrhages. The flock was vaccinated, before the outbreak, with only one dose of Clostridium perfringens type D vaccine. Two factors are suggested to be important for the occurrence of the disease: insufficient immunity due to the incorrect vaccination; and high nutritional levels by the supplementation with highly fermentable carbohydrates.

• Clostridium perfringens tipo D epsilon toxin enterotoxemia encephalomalacia

Abstract in Portuguese:

RESUMO.- Pimentel L.A., Oliveira D.M., Galiza G.J.N., Dantas A.F.M., Uzal F. & Riet-Correa F. 2010. Focal symmetrical encephalomalacia in sheep. [Encefalomalacia focal simétrica em ovino.] Pesquisa Veterinária Brasileira 30(5):423-427. Setor de Patologia Veterinária, Hospital Veterinário, CSTR, Campus de Patos, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br Encefalomalacia focal simétrica (EFS) é a lesão mais proeminente vista nas formas subaguda ou crônica da enterotoxemia por Clostridium perfringens tipo D. Este trabalho relata EFS em ovinos no semiárido do estado da Paraíba. Seis ovinos morreram, em um período de sete dias, dentro de um rebanho de 70 animais, da raça Santa Inês, entre 4-30 meses de idade, que pastavam em piquete de Cynodon dactylon (capim Tifton), que estava rebrotando. Os ovinos eram suplementados com um concentrado de soja, trigo e milho. Os sinais nervosos incluíam cegueira e decúbito lateral. Um ovino de 19 meses de idade foi examinado clinicamente e necropsiado, depois de um curso clínico de 3 dias. Macroscopicamente foram observadas herniação do cerebelo e áreas acastanhadas, multifocais, simétricas e bilaterais na cápsula interna, tálamo e pedúnculo cerebelar. Histologicamente observou-se malacia, bilateral e simétrica, com alguns neutrófilos, tumefação das células endoteliais dos vasos sanguíneos, edema perivascular e hemorragia. O rebanho foi vacinado, antes do surto, com uma única dose de vacina para Clostridium perfringens tipo D. Dois fatores são sugestivos quanto a importância da ocorrência da enfermidade: imunidade insuficiente devida à vacinação incorreta; e altos níveis nutricionais da suplementação com carboidratos altamente fermentáveis.

Abstract in English:

RESUMO.- Galiza G.J.N., Silva M.L.C.R, Dantas A.F.M., Simões S.V.D. & Riet-Correa F. 2010. [Diseases of the nervous system of cattle in the semiarid of Northeastern Brazil.] Doenças do sistema nervoso de bovinos no semiárido nordestino. Pesquisa Veterinária Brasileira 30(3):267-276. Hospital Veterinário, CSTR, Campus de Patos da Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br Para determinar as doenças que ocorrem no sistema nervoso de bovinos no semiárido nordestino, foi realizado um estudo retrospectivo em 411 necropsias de bovinos realizadas no Hospital Veterinário da Universidade Federal de Campina Grande, Patos, Paraíba, entre janeiro de 2000 a dezembro de 2008. Dos 411 casos analisados 139 (33,81%) apresentaram alterações clínicas do sistema nervoso e as fichas foram revisadas para determinar os principais achados referentes à epidemiologia, aos sinais clínicos e às alterações macroscópicas e microscópicas. Em 28 (20,14%) casos o diagnóstico foi inconclusivo. As principais enfermidades foram raiva (48,7% dos casos com sinais nervosos), abscessos cerebrais (7,2%) incluindo três casos de abscesso da pituitária, febre catarral maligna (6,3%), botulismo (6,3%), alterações congênitas (4,5%), traumatismo (4,5%), tuberculose (2,7%), tétano (2,7%), infecção por herpesvírus bovino-5 (2,7%), encefalomielite não supurativa (2,7%), intoxicação por Prosopis juliflora (2,7%), status spongiosus congênito de causa desconhecida (1,8%) e polioencefalomalacia (1,8%). Outras doenças diagnosticadas numa única oportunidade (0,9%) foram criptococose, listeriose, encefalite tromboembólica, linfossarcoma, tripanossomíase e babesiose por Babesia bovis.

• Botulism brain abscess malignant catarrhal fever pituitary abscess polioencephalomalacia rabies tuberculosis

Abstract in Portuguese:

ABSTRACT.- Galiza G.J.N., Silva M.L.C.R, Dantas A.F.M., Simões S.V.D. & Riet-Correa F. 2010. [Diseases of the nervous system of cattle in the semiarid of Northeastern Brazil.] Doenças do sistema nervoso de bovinos no semiárido nordestino. Pesquisa Veterinária Brasileira 30(3):267-276. Hospital Veterinário, CSTR, Campus de Patos da Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br Diseases of the nervous system of cattle in the semiarid region of northeastern Brazil were evaluated by a retrospective study of 411 cattle necropsies performed in the Veterinary Hospital of the Federal University of Campina Grande, Patos, Paraíba, from January 2000 to December 2008. Of the 411 cases analyzed, 139 (33.81%) were from cattle that presented nervous signs and the records were reviewed to determine the epidemiological, clinical, and macroscopic and histologic main features. Diagnosis was inconclusive in 28 cases (20.14%). In cases with diagnosis the main diseases were rabies (48.7% of the cases with nervous signs), brain abscesses (7.2%) including three cases of pituitary abscesses, malignant catarrhal fever (6.3%), botulism (6.3%), congenital malformations (4.5%), trauma (4.5%), tuberculosis (2.7%), tetanus (2.7%), infection by bovine hervesvirus-5 (2.7%), non-suppurative encephalomyelitis (2.7%), intoxication by Prosopis juliflora (2.7%), congenital status spongiosus of unknown etiology (1.8%), and polioencephalomalacia (1.8%). Other diseases diagnosed only once (0.9%) were cryptococcosis, listeriosis, thromboembolic encephalitis, lymphosarcoma, trypanosso-miasis, and babesiosis by Babesia bovis.

Abstract in English:

ABSTRACT.- Sant’Ana F.J.F., Lemos R.A.A., Nogueira A.P.A., Togni M., Tessele B. & Barros C.S.L. 2009. [Polioencephalomalacia in ruminants.] Polioencefalomalacia em ruminantes. Pesquisa Veterinária Brasileira 29(9):681-694. Laboratório de Patologia Veterinária, Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Polioencephalomalacia (PEM) of ruminants is a complex disease. The term indicates a morphological diagnosis where severe neuronal necrosis results in softening of cerebral grey matter. Initially though as a single disease caused by thiamine deficiency, PEM is currently believe to have several causes and different pathogenic mechanisms or a single pathogenic organism triggered by different agents are responsible for the disease. In this paper the possible causes and pathogenesis of PEM in ruminants are critically reviewed and discussed. Also are reviewed the epidemiology, clinical signs, gross and histological findings, methods of diagnosis, treatment and control.

• Polioencefalomalacia polioencephalomalacia

Abstract in Portuguese:

RESUMO.- Sant’Ana F.J.F., Lemos R.A.A., Nogueira A.P.A., Togni M., Tessele B. & Barros C.S.L. 2009. [Polioencephalomalacia in ruminants.] Polioencefalomalacia em ruminantes. Pesquisa Veterinária Brasileira 29(9):681-694. Laboratório de Patologia Veterinária, Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Polioencefalomalacia (PEM) de ruminantes é uma doença complexa. O termo indica um diagnóstico morfológico em que necrose neuronal grave resulta em amolecimento da substância cinzenta do cérebro. Interpretada no início como uma doença única, causada por deficiência de tiamina, acredita-se hoje que várias causas e diferentes mecanismos patogênicos, ou um único mecanismo patogênico disparado por diferentes agentes, sejam responsáveis pelo aparecimento da doença. Neste artigo, as possíveis causas e a patogênese de PEM em ruminantes são criticamente revisadas e discutidas. Também são revisadas a epidemiologia, os sinais clínicos, os achados macro e microscópicos e os métodos de diagnóstico, tratamento e controle.

Abstract in English:

ABSTRACT.- Sant’Ana F.J.F., Nogueira A.P.A., Souza R.I.C., Cardinal S.G., Lemos R.A.A. & Barros C.S.L. 2009. [Experimentally amprolium-induced polioencephalomalacia in sheep.] Polioencefalomalacia experimental induzida por amprólio em ovinos. Pesquisa Veterinária Brasileira 29(9):747-752. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br In order to establish an experimental model for the study of the etiology, pathology, and pathogenesis of polioencephalomalacia in ruminants, the condition was induced in five sheep by oral administration of amprolium at daily doses of 500 and 1,000mg per kg of body weight respectively for 28-59 days and for 13-39 days. All sheep died or were euthanized in extremis after illness of 3-7 days. Clinical signs included depression, incoordination, midriasis, grinding of the teeth, blindness, and laying down with opisthotonus and paddling movements. Drooling and a sawhorse stance were observed in one sheep and myoclonus in another one. Main gross lesions were restricted to the central nervous system and included swelling of the brain with flattening of telencephalic gyri, and hemorrhages in the parietal and occipital lobes of the telencephalon, in the submeningeal areas of the spinal cord and in the mesencephalon. Histologically, there was segmental laminar neuronal necrosis (red neurons) associated with edema, swelling of endothelial cells, hemorrhages and infiltration by foamy macrophages (gitter cells). These changes were more marked in the frontal, parietal and occipital telecephalic lobes and there was sharp demarcation between the lesions and the adjacent normal neuropile. Additionally, similar, but less marked lesions were seen in the mesencephalon, thalamus and hippocampus. Considering the consistent reproducible aspects of polioencephalomalacia in sheep using amprolium, this may be an useful model for the study of the disease.

• Amprolium polioencephalomalacia amprólio polioencefalomalacia

Abstract in Portuguese:

RESUMO.- Sant’Ana F.J.F., Nogueira A.P.A., Souza R.I.C., Cardinal S.G., Lemos R.A.A. & Barros C.S.L. 2009. [Experimentally amprolium-induced polioencephalomalacia in sheep.] Polioencefalomalacia experimental induzida por amprólio em ovinos. Pesquisa Veterinária Brasileira 29(9):747-752. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Para estabelecer um modelo experimental para o estudo da etiologia, patologia e patogênese da polioencefalomalacia em ruminantes, a condição foi induzida em cinco ovinos pela administração oral de amprólio nas doses diárias de 500 e 1.000mg/kg de peso animal, respectivamente por 28-59 dias e 13-39 dias. Todos os ovinos morreram ou foram eutanasiados in extremis após um curso clínico de 3-7 dias. Os sinais clínicos incluíam depressão, incoordenação, midríase, bruxismo, cegueira e decúbito com opistótono e movimentos de pedalagem. Salivação excessiva e posição de cavalete foi observada em um ovino e mioclonias em um outro. Os principais achados de necropsia restringiam-se ao sistema nervoso central e incluíam tumefação do encéfalo com achatamento dos giros telencefálicos e hemorragias nos lobos parietal e occipital do telencéfalo; as hemorragias ocorriam também nas áreas submeníngeas da medula espinhal e do mesencéfalo. Histologicamente, havia necrose segmentar laminar de neurônios (neurônios vermelhos) associada a edema, tumefação de células endoteliais, hemorragias e infiltração por macrófagos espumosos (células gitter). Essas alterações eram mais marcadas nos lobos frontal, parietal e occipital do telencéfalo e havia uma demarcação abrupta entre as lesões e o neurópilo normal adjacente. Adicionalmente, lesões semelhantes, mas menos acentuadas, eram observadas no mesencéfalo, tálamo e hipocampo. Levando em consideração a reproducibilidade regular dos aspectos da polioencefalomalacia em ovinos pela administração de amprólio, esse modelo pode ser útil para o estudo da doença.

Abstract in English:

ABSTRACT.- Pimentel L.A., Oliveira D.M., Galiza G.J.N., Rego R.O., Dantas A.F.M. & Riet-Correa F. 2009. [Diseases of the central nervous system in equidae in the Brazilian semiarid.] Doenças do sistema nervoso central de equídeos no semi-árido. Pesquisa Veterinária Brasileira 29(7):589-597. Hospital Veterinário, Universidade Federal de Campina Grande, Campus de Patos, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br Diseases of the central nervous system (CNS) in equidae are important in these species, and their knowledge in the different Brazilian regions is necessary to determine efficient control and preventive measures. This paper reports epidemiologic aspects, clinical signs and pathology of diseases of the CNS in equidae diagnosed by the Veterinary Pathology Laboratory at the Federal University of Campina Grande in the city of Patos, state of Paraíba, northeastern Brazil, during 2002-2008. During the period, 159 cases or outbreaks of those diseases were studied, 49 (30.8%) affecting the CNS. Hepatic encephalopathy caused by Crotalaria retusa poisoning, with 14 cases (28.5%), was the main disease observed. Tetanus was diagnosed in 13 (26.5%) cases and rabies in 11 (22.4%). In seven (14.2%) cases the death or euthanasia was due to traumatic lesions of the CNS. Also were diagnosed 1 case of leucoencephalomalacia, 1 case of encephalitis by equine herpesvirus-1, 1 case of intracarotid artery injection, 1 outbreak of Eastern equine encephalitis, 1 of Turbina cordata poisoning, and 1 of a tremogenic disease of unknown cause. In 5 cases the diagnosis was inconclusive. This paper indicates the importance of diagnostic veterinary laboratories, in the different Brazilian regions, for the knowledge of livestock diseases.

• Eastern equine encephalitis equine herpesvirus-1 hepatic encephalopaty intracarotid artery injection equine leucoencephalomalacia rabies tetanus

Abstract in Portuguese:

ABSTRACT.- Pimentel L.A., Oliveira D.M., Galiza G.J.N., Rego R.O., Dantas A.F.M. & Riet-Correa F. 2009. [Diseases of the central nervous system in equidae in the Brazilian semiarid.] Doenças do sistema nervoso central de equídeos no semi-árido. Pesquisa Veterinária Brasileira 29(7):589-597. Hospital Veterinário, Universidade Federal de Campina Grande, Campus de Patos, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br Diseases of the central nervous system (CNS) in equidae are important in these species, and their knowledge in the different Brazilian regions is necessary to determine efficient control and preventive measures. This paper reports epidemiologic aspects, clinical signs and pathology of diseases of the CNS in equidae diagnosed by the Veterinary Pathology Laboratory at the Federal University of Campina Grande in the city of Patos, state of Paraíba, northeastern Brazil, during 2002-2008. During the period, 159 cases or outbreaks of those diseases were studied, 49 (30.8%) affecting the CNS. Hepatic encephalopathy caused by Crotalaria retusa poisoning, with 14 cases (28.5%), was the main disease observed. Tetanus was diagnosed in 13 (26.5%) cases and rabies in 11 (22.4%). In seven (14.2%) cases the death or euthanasia was due to traumatic lesions of the CNS. Also were diagnosed 1 case of leucoencephalomalacia, 1 case of encephalitis by equine herpesvirus-1, 1 case of intracarotid artery injection, 1 outbreak of Eastern equine encephalitis, 1 of Turbina cordata poisoning, and 1 of a tremogenic disease of unknown cause. In 5 cases the diagnosis was inconclusive. This paper indicates the importance of diagnostic veterinary laboratories, in the different Brazilian regions, for the knowledge of livestock diseases.

Abstract in English:

ABSTRACT.- Sant’Ana F.J.F., Rissi D.R., Lucena R.B., Lemos R.A.A., Nogueira A.P.A. & Barros C.S.L. 2009. [Bovine polioencephalomalacia: epidemiology, clinical signs and distribution of lesions in the brain.] Polioencefalomalacia em bovinos: epidemiologia, sinais clínicos e distribuição das lesões no encéfalo. Pesquisa Veterinária Brasileira 29(7):487-497. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Thirty one cases of polioencephalomalacia (PEM) diagnosed from 1999-2008 in cattle from the Southern (13 cases) and Midwestern (18 cases) Brazil were studied. Morbidity (0.04%-6.66 %), mortality (0.04%-6.66 %), and lethality (50%-100%) rates were similar in both regions studied. There was no clear association between PEM cases and age, sex or seasonality. Cases occurred mainly in cattle raised at pasture; in the Southern the disease affected mainly young cattle (one-year old or less) while mainly older cattle (three-year-old or older) were affected in the Midwest. Clinical signs more frequently observed included blindness, incoordination, circling, opisthotonus, recumbence and peddling movements. Clinical course varied from 12 hours to 8 days (average three days and a half). In 11 cases no gross changes were observed in the brain. Main gross findings in the brain of remaining cases included congestion with swelling and flattening of gyri, softening and yellow discoloration of cerebral cortex, hemorrhagic foci in the brain stem, cerebellum and telencephalon, and cerebellar herniation. The main histopathological changes were in the cortex of occipital, parietal and frontal telencephalic lobes; however less prominent and less frequently found lesions occurred in the hippocampus, basal nuclei, thalamus, midbrain, and cerebellum. The type of microscopic cortical lesions was consistent in all cases and included segmentar laminar neuronal necrosis (red neurons), spongiosis, swollen of vascular endothelial nuclei, Alzheimer type II astrocytes and infiltration of gitter cells. In 20% of the cases there was mild lymphohistiocytic cellular infiltrate and in 13% of the cases there was mild infiltrate by neutrophils and eosinophils. Additionally, mild to moderate necro-hemorrhagic lesions were observed in 49% of the cases in the basal nuclei, in 39% of the cases in brain stem and in 26% of the cases in the thalamus. Brain lesions were consistently found in the cortical laminae of the occipital, parietal and frontal telencephalic lobes. In such locations, most frequently affected cortical layers both by neuronal necrosis and edema were external and internal granular layers. Both gyri and sulci were equally affected.

• Diseases of cattle neuropathology distribution of lesions polioencephalomalacia

Abstract in Portuguese:

RESUMO.- Sant’Ana F.J.F., Rissi D.R., Lucena R.B., Lemos R.A.A., Nogueira A.P.A. & Barros C.S.L. 2009. [Bovine polioencephalomalacia: epidemiology, clinical signs and distribution of lesions in the brain.] Polioencefalomalacia em bovinos: epidemiologia, sinais clínicos e distribuição das lesões no encéfalo. Pesquisa Veterinária Brasileira 29(7):487-497. Departamento de Patologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br RESUMO.- Trinta e um casos de polioencefalomalacia (PEM) diagnosticados de 1999-2008 em bovinos do Sul (13 casos) e Centro-Oeste (18 casos) brasileiros foram estudados. As taxas de morbidade (0,04%-6,66 %), mortalidade (0,04%-6,66 %) e letalidade (50%-100%) foram semelhantes em ambas as regiões estudadas. Não houve uma associação clara entre os casos de PEM e a idade, sexo dos bovinos e sazonalidade. Os casos ocorreram principalmente em bovinos criados de forma extensiva em pastagem. Na Região Sul a doença afetou principalmente bovinos jovens (um ano de idade ou menos), enquanto que principalmente bovinos mais velhos (3 anos de idade ou mais) foram afetados no Centro-Oeste. Os sinais clínicos mais frequentemente observados incluíram cegueira, incoordenação, andar em círculos, opistótono, decúbito e movimentos de pedalagem. A evolução do quadro clínico variou de 12 horas a 8 dias (media 3 dias e meio). Em 11 encéfalos não foram observadas alterações macroscópicas; as principais alterações macroscópicas nos outros casos incluíam congestão com tumefação e achatamento das circunvoluções, amolecimento e amarelamento do córtex telencefálico, focos de hemorragia no tronco encefálico, cerebelo e telencéfalo e herniação cerebelar. As principais alterações histológicas ocorreram no córtex dos lobos telencefálicos occipital, parietal e frontal; no entanto, lesões menos acentuadas e menos frequentemente observadas ocorreram no hipocampo, núcleos da base, tálamo, mesencéfalo e cerebelo. O tipo de lesão microscópica cortical era consistente em todos os casos e incluía necrose neuronal (neurônio vermelho) laminar segmentar, espongiose, tumefação do núcleo das células endoteliais, astrócitos Alzheimer tipo II e infiltração por células gitter. Em 20% dos casos havia um leve infiltrado celular linfo-histiocitário e em 13% dos casos havia leve infiltrado de neutrófilos e eosinófilos. Adicionalmente, lesões necro-hemorrágicas leves ou moderadas foram observadas em 49% dos casos nos núcleos da base, em 39% dos casos no tronco encefálico e em 26% dos casos no tálamo. Lesões telencefálicas foram consistentemente observadas nas lâminas dos córtices dos lobos occipital, parietal e frontal. Nessas regiões as camadas granular externa e interna foram as mais afetadas tanto por neurônios necróticos quanto por edema em todas as regiões avaliadas. Tanto os giros quanto os sulcos foram afetados igualmente.

Abstract in English:

ABSTRACT.- David N., Hubner S.O., Riet-Correa F., Halfen D. & Lemos R.A. 2007. Reactivation of latent bovine herpesvirus type 5 in cattle with polioencephalomalacia induced by ammonium sulphate. Pesquisa Veterinária Brasileira 27(10):435-441. Hospital Veterinário, CSTR, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: franklin.riet@pesquisador.cnpq.br In the state Mato Grosso do Sul, Brazil, outbreaks of meningoencephalitis by BoHV-5 and polioencephalomalacia (PEM) display similar epidemiological features, suggesting that meningoencephalitis may be associated with reactivation of a latent BoHV-5 infection, during the development of PEM. To test this hypothesis, four 7-8 months old steers negative for BoHV-5 antibodies were inoculated intranasally with BoHV-5 and received amprolium from day 35 to day 105 after inoculation. Because PEM was not produced during this period, ammonium sulphate was given from day 114 to day 180 after inoculation. Two uninfected control steers received amprolium and ammonium sulphate for the same periods. All inoculated cattle developed antibodies against BoHV-5 after inoculation and the virus was isolated from nasal swabs, indicating that they were infected. Two inoculated steers had clinical signs of PEM after 118 and 146 days after virus inoculation. One was euthanized after a clinical manifestation period of seven days and had severe lesions of PEM and meningoencephalitis. BoHV-5 was isolated from the central nervous system of this animal. The other animal recovered but continued to manifest chronic signs of PEM and was euthanatized. On histological examination, the cerebral cortex, caudate nucleus and thalamus had multifocal areas of malacia and mild meningoencephalitis of the cortex. BoHV-5 was not isolated from the brain. One uninfected control steer had signs of neurological disease on day 158 and had lesions of PEM without meningoencephalitis at necropsy. The simultaneous production of PEM and diffuse meningoencephalitis, with isolation of BoHV-5, in one steer treated with ammonium sulphate, 118 days after BoHV-5 inoculation, suggests that latent BoHV-5 was reactivated in this animal submitted to experimental induction of PEM.

• Polioencephalomalacia bovine herpesvirus type 5 viral reactivation cattle

Abstract in Portuguese:

ABSTRACT.- David N., Hubner S.O., Riet-Correa F., Halfen D. & Lemos R.A. 2007. Reactivation of latent bovine herpesvirus type 5 in cattle with polioencephalomalacia induced by ammonium sulphate. Pesquisa Veterinária Brasileira 27(10):435-441. Hospital Veterinário, CSTR, Universidade Federal de Campina Grande, Campus de Patos, 58700-000 Patos, PB, Brazil. E-mail: franklin.riet@pesquisador.cnpq.br In the state Mato Grosso do Sul, Brazil, outbreaks of meningoencephalitis by BoHV-5 and polioencephalomalacia (PEM) display similar epidemiological features, suggesting that meningoencephalitis may be associated with reactivation of a latent BoHV-5 infection, during the development of PEM. To test this hypothesis, four 7-8 months old steers negative for BoHV-5 antibodies were inoculated intranasally with BoHV-5 and received amprolium from day 35 to day 105 after inoculation. Because PEM was not produced during this period, ammonium sulphate was given from day 114 to day 180 after inoculation. Two uninfected control steers received amprolium and ammonium sulphate for the same periods. All inoculated cattle developed antibodies against BoHV-5 after inoculation and the virus was isolated from nasal swabs, indicating that they were infected. Two inoculated steers had clinical signs of PEM after 118 and 146 days after virus inoculation. One was euthanized after a clinical manifestation period of seven days and had severe lesions of PEM and meningoencephalitis. BoHV-5 was isolated from the central nervous system of this animal. The other animal recovered but continued to manifest chronic signs of PEM and was euthanatized. On histological examination, the cerebral cortex, caudate nucleus and thalamus had multifocal areas of malacia and mild meningoencephalitis of the cortex. BoHV-5 was not isolated from the brain. One uninfected control steer had signs of neurological disease on day 158 and had lesions of PEM without meningoencephalitis at necropsy. The simultaneous production of PEM and diffuse meningoencephalitis, with isolation of BoHV-5, in one steer treated with ammonium sulphate, 118 days after BoHV-5 inoculation, suggests that latent BoHV-5 was reactivated in this animal submitted to experimental induction of PEM.

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:

Riet-Correa G., Duarte M.D., Barbosa J.D., Oliveira C.M.C., Cerqueira V.D., Brito M.F. & Riet-Correa F. 2006. [Meningoencephalitis and polioencephalomalacia caused by Bovine herpesvirus-5 in the state of Pará, northern Brazil.] Meningoencefalite e polioencefalomalacia causadas por Herpesvírus bovino-5 no Estado do Pará. Pesquisa Veterinária Brasileira 26(1):44-46. Central de Diagnóstico Veterinário, Universidade Federal do Pará, Maximino Porpino 1000, Castanhal, PA 68740-080, Brazil. E-mail: griet@ufpa.br Four outbreaks of meningoencephalitis in 1 to 2 years old cattle caused by Bovine herpesvirus-5 are reported in four municipalities in the state of Pará, northern Brazil. In three outbreaks only one animal was affected, in another 3 cattle were affected. Main clinical signs were incoordination, dullness, blindness, recumbence, and opisthotonus. Death occurred after a clinical manifestation period of 3-4 days. Softening and yellowish areas were observed grossly in the cerebral cortex. The histology revealed poliencephalomalacia in the cerebral cortex, thalamus and basal nuclei, and non suppurative encephalitis and meningitis, and eosinophilic intranuclear inclusion bodies in astrocytes. The diagnosis was based on the typical microscopic lesions.

• Meningoencephalitis polioencephalomalacia bovine herpesvirus-5 cattle.

Abstract in Portuguese:

Riet-Correa G., Duarte M.D., Barbosa J.D., Oliveira C.M.C., Cerqueira V.D., Brito M.F. & Riet-Correa F. 2006. [Meningoencephalitis and polioencephalomalacia caused by Bovine herpesvirus-5 in the state of Pará, northern Brazil.] Meningoencefalite e polioencefalomalacia causadas por Herpesvírus bovino-5 no Estado do Pará. Pesquisa Veterinária Brasileira 26(1):44-46. Central de Diagnóstico Veterinário, Universidade Federal do Pará, Maximino Porpino 1000, Castanhal, PA 68740-080, Brazil. E-mail: griet@ufpa.br Four outbreaks of meningoencephalitis in 1 to 2 years old cattle caused by Bovine herpesvirus-5 are reported in four municipalities in the state of Pará, northern Brazil. In three outbreaks only one animal was affected, in another 3 cattle were affected. Main clinical signs were incoordination, dullness, blindness, recumbence, and opisthotonus. Death occurred after a clinical manifestation period of 3-4 days. Softening and yellowish areas were observed grossly in the cerebral cortex. The histology revealed poliencephalomalacia in the cerebral cortex, thalamus and basal nuclei, and non suppurative encephalitis and meningitis, and eosinophilic intranuclear inclusion bodies in astrocytes. The diagnosis was based on the typical microscopic lesions.