PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Peixoto P.V., Ribeiro C.T., Bezerra Jr P.S., Driemeier D. & França T.N. 2008. Proliferative enteropathy (Lawsonia intracellularis) outbreak in rabbits in Brazil. Pesquisa Veterinária Brasileira 28(10):447-451. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br An outbreak of Lawsonia intracellularis infection in rabbits, which occurred in 1988 in Rio de Janeiro state, Brazil, is reported. The disease had an acute course (24-48 hours) with clinical signs characterized by brownish or green diarrhea and dehydration. Occasionally, the animals died one day after the onset of diarrhea, without showing any other clinical signs. At necropsy, the ileum was prominent, firm and had a thickened wall; it was dilated in the caudal direction and had a somewhat reticulated appearance, perceptible through the serosa. The thickened mucous membrane had finely corrugated aspect and a shiny surface. The ileocecal valve and surrounding areas were slightly edematous and irregular. The Peyer’s patches were sometimes more evident. There was moderate enlargement of the mesenteric lymph nodes. The histological examination revealed different degrees of hyperplasia of the epithelial cells of intestinal crypts consisting of poorly differentiated, hyperchromatic cells with high mitotic index, arranged in a pseudostratified layer which, in some cases, reached the apical portions of the villi. The inflammatory infiltrate between the hyperplastic epithelial cells was composed of lymphocytes, plasma cells, macrophages, some eosinophils and globular leukocytes. Silver impregnation revealed large numbers of bacteria with morphology of the genus Lawsonia in the apical pole of cryptal enterocytes. These bacteria reacted positively to a Lawsonia intracellularis polyclonal antibody by the avidin-biotin immunohistochemistry method.

• Lawsonia intracellularis proliferative enteropathy rabbits Brazil

Abstract in Portuguese:

ABSTRACT.- Peixoto P.V., Ribeiro C.T., Bezerra Jr P.S., Driemeier D. & França T.N. 2008. Proliferative enteropathy (Lawsonia intracellularis) outbreak in rabbits in Brazil. Pesquisa Veterinária Brasileira 28(10):447-451. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br An outbreak of Lawsonia intracellularis infection in rabbits, which occurred in 1988 in Rio de Janeiro state, Brazil, is reported. The disease had an acute course (24-48 hours) with clinical signs characterized by brownish or green diarrhea and dehydration. Occasionally, the animals died one day after the onset of diarrhea, without showing any other clinical signs. At necropsy, the ileum was prominent, firm and had a thickened wall; it was dilated in the caudal direction and had a somewhat reticulated appearance, perceptible through the serosa. The thickened mucous membrane had finely corrugated aspect and a shiny surface. The ileocecal valve and surrounding areas were slightly edematous and irregular. The Peyer’s patches were sometimes more evident. There was moderate enlargement of the mesenteric lymph nodes. The histological examination revealed different degrees of hyperplasia of the epithelial cells of intestinal crypts consisting of poorly differentiated, hyperchromatic cells with high mitotic index, arranged in a pseudostratified layer which, in some cases, reached the apical portions of the villi. The inflammatory infiltrate between the hyperplastic epithelial cells was composed of lymphocytes, plasma cells, macrophages, some eosinophils and globular leukocytes. Silver impregnation revealed large numbers of bacteria with morphology of the genus Lawsonia in the apical pole of cryptal enterocytes. These bacteria reacted positively to a Lawsonia intracellularis polyclonal antibody by the avidin-biotin immunohistochemistry method.

Abstract in English:

ABSTRACT.- Vasconcelos J.S., Riet-Correa F., Dantas A.F., Medeiros R.M.T. & Dantas A.J.A. 2008. [Sudden deaths caused by Palicourea aeneofusca (Rubiaceae) and Mascagnia rigida (Malpighiaceae) in cattle in the Zona da Mata of Paraíba.] Mortes súbitas em bovinos causadas por Palicourea aeneofusca (Rubiaceae) e Mascagnia rigida (Malpighiaceae) na Zona da Mata Paraibana. Pesquisa Veterinária Brasileira 28(10):457-460. Hospital Veterinário, CSTR, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br. This paper reports an outbreak of poisoning by Palicourea aeneofusca in cattle, in the municipality of Jacaraú, and another by Mascagnia rigida in the municipality of Sapé. Both outbreaks occurred in the Zona da Mata of Paraíba, where there are no previous reports of poisoning by toxic plants causing sudden death associated to exercise. The toxicity of both plants was tested in rabbits. The lethal dose was of 3g per kg body weight (g/kg) for fresh P. aeneofusca and 10g/kg for fresh Mascagnia rigida. On the farm where the poisoning by P. aeneofusca was observed, M. rigida also was found. The farmer reported that this plant also caused sudden death previously. M. rigida collected on that farm and given dried to rabbits caused death at the dose of 10gkg. The poisoning by P. aeneofusca in cattle had been previously reported in the Zona da Mata and Agreste of Pernambuco and east of Bahia. There are also numerous farmers’ reports about the occurrence of the poisoning in the Zona da Mata of Alagoas, suggesting that it occurs in the whole coastal region, from Bahia to Paraíba. M. rigida is the most important toxic plant for cattle in the Brazilian semiarid. The results of this paper demonstrate that this plant poisoning also occurs in the tropical wet climate of the Zona da Mata.

• Toxic plants Palicourea aeneofusca Mascagnia rigida cattle rabbits plant poisoning fluoroacetic acid cardiac failure

Abstract in Portuguese:

ABSTRACT.- Vasconcelos J.S., Riet-Correa F., Dantas A.F., Medeiros R.M.T. & Dantas A.J.A. 2008. [Sudden deaths caused by Palicourea aeneofusca (Rubiaceae) and Mascagnia rigida (Malpighiaceae) in cattle in the Zona da Mata of Paraíba.] Mortes súbitas em bovinos causadas por Palicourea aeneofusca (Rubiaceae) e Mascagnia rigida (Malpighiaceae) na Zona da Mata Paraibana. Pesquisa Veterinária Brasileira 28(10):457-460. Hospital Veterinário, CSTR, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br. This paper reports an outbreak of poisoning by Palicourea aeneofusca in cattle, in the municipality of Jacaraú, and another by Mascagnia rigida in the municipality of Sapé. Both outbreaks occurred in the Zona da Mata of Paraíba, where there are no previous reports of poisoning by toxic plants causing sudden death associated to exercise. The toxicity of both plants was tested in rabbits. The lethal dose was of 3g per kg body weight (g/kg) for fresh P. aeneofusca and 10g/kg for fresh Mascagnia rigida. On the farm where the poisoning by P. aeneofusca was observed, M. rigida also was found. The farmer reported that this plant also caused sudden death previously. M. rigida collected on that farm and given dried to rabbits caused death at the dose of 10gkg. The poisoning by P. aeneofusca in cattle had been previously reported in the Zona da Mata and Agreste of Pernambuco and east of Bahia. There are also numerous farmers’ reports about the occurrence of the poisoning in the Zona da Mata of Alagoas, suggesting that it occurs in the whole coastal region, from Bahia to Paraíba. M. rigida is the most important toxic plant for cattle in the Brazilian semiarid. The results of this paper demonstrate that this plant poisoning also occurs in the tropical wet climate of the Zona da Mata.

Abstract in English:

Santurio J.M., Leal A.T., Leal A.B.M., Alves S.H., Lübeck I., Griebeler J. & Copetti M.V. 2006. [Indirect ELISA for the serodiagnostic of pythiosis.] Teste de ELISA indireto para o diagnóstico sorológico de pitiose. Pesquisa Veterinária Brasileira 26(1):47-50. Departamento de Microbiologia, Universidade Federal de Santa Maria, prédio 20, sala 4139, Lapemi, Santa Maria, RS 97105-900, Brazil. E-mail: santurio@smail.ufsm.br Pythiosis is a granulomatous disease caused by the oomycete Pythium insidiosum that affects humans and animals, especially horses. Deaths are very often the consequence of incorrect or late diagnosis when animals no longer respond to treatment. This study aimed standardization of the ELISA assay for the serodiagnostic of pythiosis in horses and rabbits, in order to minimize errors and delays in the diagnosis of the disease. Sera of 72 healthy and 44 of by pythiosis affected horses were used for development and evaluation of the test. The ELISA for equine diagnostic showed 97.72% sensitivity, 90.27% specificity, 86% positive predictive value, 98.4% negative predictive value, and 93.1% efficiency. The rabbit test was standardized with 48 sera of healthy rabbits and 24 sera of rabbits immunized with P. insidiosum antigens. The results were 91.66 % sensitivity, 95.83% specificity, 91.66% positive predictive value, 95.83% negative predictive value, and 94.44% efficiency. It can be concluded that ELISA is a reliable test for diagnostic and serological monitoring of pythiosis.

• Pythium insidiosum pythiosis ELISA horses rabbits.

Abstract in Portuguese:

Santurio J.M., Leal A.T., Leal A.B.M., Alves S.H., Lübeck I., Griebeler J. & Copetti M.V. 2006. [Indirect ELISA for the serodiagnostic of pythiosis.] Teste de ELISA indireto para o diagnóstico sorológico de pitiose. Pesquisa Veterinária Brasileira 26(1):47-50. Departamento de Microbiologia, Universidade Federal de Santa Maria, prédio 20, sala 4139, Lapemi, Santa Maria, RS 97105-900, Brazil. E-mail: santurio@smail.ufsm.br Pythiosis is a granulomatous disease caused by the oomycete Pythium insidiosum that affects humans and animals, especially horses. Deaths are very often the consequence of incorrect or late diagnosis when animals no longer respond to treatment. This study aimed standardization of the ELISA assay for the serodiagnostic of pythiosis in horses and rabbits, in order to minimize errors and delays in the diagnosis of the disease. Sera of 72 healthy and 44 of by pythiosis affected horses were used for development and evaluation of the test. The ELISA for equine diagnostic showed 97.72% sensitivity, 90.27% specificity, 86% positive predictive value, 98.4% negative predictive value, and 93.1% efficiency. The rabbit test was standardized with 48 sera of healthy rabbits and 24 sera of rabbits immunized with P. insidiosum antigens. The results were 91.66 % sensitivity, 95.83% specificity, 91.66% positive predictive value, 95.83% negative predictive value, and 94.44% efficiency. It can be concluded that ELISA is a reliable test for diagnostic and serological monitoring of pythiosis.

Abstract in English:

Diel D.G., Fonseca E.T., Souza S.F., Mazzanti A., Bauermann F., Weiblen R. & Flores E.F. 2005. [Bovine herpesvirus 5 may use the olfactory and trigeminal pathways to invade the central nervous system of rabbits, depending upon the route of inoculation.] O Herpesvírus bovino tipo 5 (BoHV-5) pode utilizar as rotas olfatória ou trigeminal para invadir o sistema nervoso central de coelhos, dependendo da via de inoculação. Pesquisa Veterinária Brasileira 25(3):164-170. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: flores@ccr.ufsm.br Bovine herpesvirus type 5 (BoHV-5) is a major etiological agent of meningoencephalitis in cattle. Following replication in the nasal mucosa, viral invasion of the brain is thought to occur mainly by the olfactory pathway. To address the role of this pathway in the pathogenesis of neurological infection in a laboratory model, 30 days old rabbits had the main olfactory bulbs (MOBs) surgically removed and were subsequently inoculated intranasally (IN) or conjunctivally (IC) with a highly neurovirulent BoHV-5 strain (SV-507). Following IN inoculation, 10 out of 10 (100 %) control rabbits developed neurological disease. The clinical onset ranged from day 5 to 10 post-inoculation (pi, average 7.5 days); nine being euthanized in extremis and one recovering after a mild clinical course. In contrast, only one rabbit (9.1 %) of the group lacking the MOBs (n=11) developed neurological disease (onset at day 17 pi). Dexamethasone administration to the survivors (n=10) at day 50pi was followed by virus shedding in nasal and/or ocular secretions by 8 animals, demonstrating that the virus was able to reach the trigeminal ganglia (TG) during acute infection. These results demonstrate that the olfactory route provides the main, yet not the sole access to the brain of rabbits following IN inoculation. To address the role of a second pathway, groups of control (n=12) or MOB-lacking rabbits (n=12) were inoculated into the conjunctival sac (IC), following which the virus would be expected to use the ophtalmic branch of the trigeminal nerve to reach the brain. Ten control rabbits (83.3 %) developed neurological disease upon IC inoculation (onset 15.3 days [11 to 20]). Previous ablation of the MOBs did not affect the frequency and course of neurological disease: ten out of 12 rabbits (83.3 %) lacking the MOBs developed neurological disease (onset 9 to 15 dpi, average: 12.7 days) upon IC inoculation. These results demonstrate that both IN and IC routes may operate in the transport of BoHV-5 to the brain of experimentally infected rabbits, depending on the route of inoculation. IN inoculation results in a fast and efficient transport by the olfactory pathway, the trigeminal route providing an alternative, much slower and less efficient transport; IC inoculation results in efficient viral transport by the trigeminal route, yet with a delayed kinetics comparing to the transport provided by the olfactory pathway.

• Bovine herpesvirus type 5 BoHV-5 neurological infection rabbits.

Abstract in Portuguese:

Diel D.G., Fonseca E.T., Souza S.F., Mazzanti A., Bauermann F., Weiblen R. & Flores E.F. 2005. [Bovine herpesvirus 5 may use the olfactory and trigeminal pathways to invade the central nervous system of rabbits, depending upon the route of inoculation.] O Herpesvírus bovino tipo 5 (BoHV-5) pode utilizar as rotas olfatória ou trigeminal para invadir o sistema nervoso central de coelhos, dependendo da via de inoculação. Pesquisa Veterinária Brasileira 25(3):164-170. Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: flores@ccr.ufsm.br Bovine herpesvirus type 5 (BoHV-5) is a major etiological agent of meningoencephalitis in cattle. Following replication in the nasal mucosa, viral invasion of the brain is thought to occur mainly by the olfactory pathway. To address the role of this pathway in the pathogenesis of neurological infection in a laboratory model, 30 days old rabbits had the main olfactory bulbs (MOBs) surgically removed and were subsequently inoculated intranasally (IN) or conjunctivally (IC) with a highly neurovirulent BoHV-5 strain (SV-507). Following IN inoculation, 10 out of 10 (100 %) control rabbits developed neurological disease. The clinical onset ranged from day 5 to 10 post-inoculation (pi, average 7.5 days); nine being euthanized in extremis and one recovering after a mild clinical course. In contrast, only one rabbit (9.1 %) of the group lacking the MOBs (n=11) developed neurological disease (onset at day 17 pi). Dexamethasone administration to the survivors (n=10) at day 50pi was followed by virus shedding in nasal and/or ocular secretions by 8 animals, demonstrating that the virus was able to reach the trigeminal ganglia (TG) during acute infection. These results demonstrate that the olfactory route provides the main, yet not the sole access to the brain of rabbits following IN inoculation. To address the role of a second pathway, groups of control (n=12) or MOB-lacking rabbits (n=12) were inoculated into the conjunctival sac (IC), following which the virus would be expected to use the ophtalmic branch of the trigeminal nerve to reach the brain. Ten control rabbits (83.3 %) developed neurological disease upon IC inoculation (onset 15.3 days [11 to 20]). Previous ablation of the MOBs did not affect the frequency and course of neurological disease: ten out of 12 rabbits (83.3 %) lacking the MOBs developed neurological disease (onset 9 to 15 dpi, average: 12.7 days) upon IC inoculation. These results demonstrate that both IN and IC routes may operate in the transport of BoHV-5 to the brain of experimentally infected rabbits, depending on the route of inoculation. IN inoculation results in a fast and efficient transport by the olfactory pathway, the trigeminal route providing an alternative, much slower and less efficient transport; IC inoculation results in efficient viral transport by the trigeminal route, yet with a delayed kinetics comparing to the transport provided by the olfactory pathway.

Abstract in English:

Aguirre J.I., Gomar M.S., Igal, S., Quiroga M.A., Portiansky E.L & Gimeno E.J. 2005. Bone changes caused by experimental Solanum malacoxylon poisoning in rabbits. [Alterações ósseas causadas na intoxicação experimental por Solanum malacoxylon em coelhos.] Pesquisa Veterinária Brasileira 25(1):34-38. Institute of Pathology “Prof. Dr. Bernardo Epstein”, School of Veterinary Sciences, National University of La Plata, P.O.Box 296, (1900) La Plata, Argentina. E-mail: ejgimeno@fcv.unlp.edu.ar The aim of this study was to describe the bone changes observed after a daily oral administration of the calcinogenic plant Solanum malacoxylon (syn. S. glaucophyllum) (Sm) during 9 days. The Sm-poisoned rabbits had an increase of bone resorption in the endosteal surface of the cortical zone and also in the surface covered by osteoblasts of the primary and secondary spongiosa of the trabecular bone compartment. Moreover, the epiphyseal growth plates in long bones appeared narrower than in the control rabbits, with reduction of the proliferative and hyperthrophic chondrocyte zones. The electron microscopic study revealed a significant decrease of proteoglycans in the hyperthrophic chondrocyte zone evidenced by a significant reduction of rutenium red positive granules in the poisoned rabbit. Altogether, these data suggest that cell differentiation may play a pivotal role in the pathogenesis of Sm-induced bone lesions.

• Solanum malacoxylon S. glaucophyllum calcinogenic plant rabbit bone tissue growth plate.

Abstract in Portuguese:

Aguirre J.I., Gomar M.S., Igal, S., Quiroga M.A., Portiansky E.L & Gimeno E.J. 2005. Bone changes caused by experimental Solanum malacoxylon poisoning in rabbits. [Alterações ósseas causadas na intoxicação experimental por Solanum malacoxylon em coelhos.] Pesquisa Veterinária Brasileira 25(1):34-38. Institute of Pathology “Prof. Dr. Bernardo Epstein”, School of Veterinary Sciences, National University of La Plata, P.O.Box 296, (1900) La Plata, Argentina. E-mail: ejgimeno@fcv.unlp.edu.ar The aim of this study was to describe the bone changes observed after a daily oral administration of the calcinogenic plant Solanum malacoxylon (syn. S. glaucophyllum) (Sm) during 9 days. The Sm-poisoned rabbits had an increase of bone resorption in the endosteal surface of the cortical zone and also in the surface covered by osteoblasts of the primary and secondary spongiosa of the trabecular bone compartment. Moreover, the epiphyseal growth plates in long bones appeared narrower than in the control rabbits, with reduction of the proliferative and hyperthrophic chondrocyte zones. The electron microscopic study revealed a significant decrease of proteoglycans in the hyperthrophic chondrocyte zone evidenced by a significant reduction of rutenium red positive granules in the poisoned rabbit. Altogether, these data suggest that cell differentiation may play a pivotal role in the pathogenesis of Sm-induced bone lesions.

Abstract in English:

ABSTRACT.- Spilki F.R., Esteves P.A., Franco A.C., Lima M., Holz C.L., Batista H.B.C.R., Driemeier D., Flores E.F., Weiblen R. & Roehe P.M. 2002. [Neurovirulence and neuroinvasiveness of bovine herpesvirus type 1 and 5 in rabbits.] Neurovirulência e neuroinvasividade de Herpesvírus bovinos tipos 1 e 5 em coelhos. Pesquisa Veterinária Brasileira 22(2):58-63. Centro de Pesquisas Veterinárias Desidério Finamor, Estrada do Conde 6000, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@orion.ufrgs.br In order to determine the capacity of bovine herpesvirus type 1 and 5 (BHV-1 and BHV-5) to invade, multiply and spread along the central nervous system (CNS) (neuroinvasiveness), as well as their potential to induce neurological illness (neurovirulence), 30 to 35 days old rabbits were inoculated with the BHV-5 strain EVI 88 / 95 and Los Angeles and Cooper BHV-1 strains, by the intrathecal (IT) and intranasal (IN) routes. The BHV-5 strain induced severe neurological clinical signs in 100% (12/12) of the rabbits inoculated by both routes. Histopathological examination revealed multifocal non-suppurative meningoencephalitis, characterized by multifocal gliosis and perivascular cuffing. Virus was recovered from many parts of the brain. Both BHV-1 strains, when inoculated via 1T route, were not neurovirulent. The strain Los Angeles, after IN inoculation, induced signs of severe respiratory disease (7/7), as well as signs of neurological impairment, indistinguishable from those induced by BHV-5, in 57% (4/7) of the infected rabbits. However, the rabbits with nervous signs revealed at histopathology vasculitis and thrombosis in lungs and brain, the latter with foci of neuronal necrosis, but no lesions indicative of encephalitis, suggesting that neural damage was probably consequent to tissue anoxia. The BHV-1 strain Cooper, after IN inoculation, induced only mild signs of respiratory disease. These findings indicate that the BHV-5 strain was both neuroinvasive and neurovirulent, since it was capable of invading, spreading and multiplying in the rabbits brains by both routes of inoculation, yet causing neurological disease, apparently consequent to vírus induced neural damage. The BHV-1 Los Angeles strain was not neuroinvasive, whereas its neurovirulence was probably consequent to tissue anoxia, which histologically seemed not to be related to direct viral pathogenic effect. The BHV-1 strain Cooper was neither neurovirulent nor neuroinvasive for rabbits. It is possible that these observations bear relationship with the frequent association of BHV-5 with encephalitis in cattle, as opposed to BHV-1 encephalitis, which is a rare event in nature.

• Infectious bovine rhinotracheitis IBR BHV-1 bovine encephalitis herpesvirus BHV-5 Rinotraqueíte infecciosa bovina herpesvírus da encefalite bovina.

Abstract in Portuguese:

RESUMO.- Spilki F.R., Esteves P.A., Franco A.C., Lima M., Holz C.L., Batista H.B.C.R., Driemeier D., Flores E.F., Weiblen R. & Roehe P.M. 2002. [Neurovirulence and neuroinvasiveness of bovine herpesvirus type 1 and 5 in rabbits.] Neurovirulência e neuroinvasividade de Herpesvírus bovinos tipos 1 e 5 em coelhos. Pesquisa Veterinária Brasileira 22(2):58-63. Centro de Pesquisas Veterinárias Desidério Finamor, Estrada do Conde 6000, Cx. Postal 47, Eldorado do Sul, RS 92990-000, Brazil. E-mail: proehe@orion.ufrgs.br Com o objetivo de avaliar a capacidade dos herpesvírus bovinos tipos 1 e 5 (BHV-1 e BHV-5) de invadir e replicar no sistema nervoso central (SNC) (neuroinvasividade), bem como sua capacidade de induzir doença neurológica (neurovirulência), coelhos com 30 a 35 dias de idade foram inoculados com uma amostra do Herpesvírus da Encefalite Bovina (BHV-5; amostra EVI 88/95) ou com amostras de BHV-1 (Los Angeles ou Cooper), pelas vias intratecal (IT) e intranasal (IN). A inoculação da amostra de BHV-5, tanto pela via 1T como IN, induziu sinais clínicos neurológicos em 100% (12/12) dos coelhos inoculados. Os exames histopatológicos revelaram um quadro de meningoencefalite não-purulenta multifocal, caracterizada por gliose multifocal e infiltrados perivasculares. O vírus foi isolado de várias áreas do SNC desses animais. As amostras de BHV-1, quando inoculadas pela via IT, não foram neurovirulentas. A amostra Los Angeles de BHV-1, quando administrada pela via IN, induziu sinais respiratórios severos, além de sinais neurológicos em 57% (4/7) dos animais inoculados. Entretanto, o exame histopatológico destes quatro animais revelou vasculite e trombose no pulmão e cérebro, este último apresentando focos de necrose neuronal, porém sem lesões indicativas de encefalite. Isso sugere que os sinais neurológicos foram, provavelmente, consequentes a prejuízos no fluxo sangüíneo encefálico, e não a danos neuronais provocados pela inoculação desse vírus. A amostra Cooper de BHV-1, quando inoculada pela via IN, induziu apenas sinais leves de infecção respiratória. Estes resultados indicam que apenas a amostra de BHV-5 foi capaz de invadir e replicar no encéfalo dos coelhos quando inoculada tanto por via IN como IT, apresentando neuroinvasividade e neurovirulência. É possível que estas observações tenham relação com o fato de amostras de BHV-5 freqüentemente causarem encefalites, em contraposição a infecções pelo BHV-1, onde encefalites são raramente observadas.

Abstract in English:

ABSTRACT.- Beltrão, N., Flores E.F., Weiblen R., Silva A.M., Roehe, P.M. & lrigoyen L.F. 2000. [Acute infection and neurological disease by bovine herpesvirus type-5 (BHV-5): Rabbits as an experimental model.] Infecção aguda e enfermidade neurológica pelo herpesvírus bovino tipo 5 (BHV-5): coelhos como modelo experimental. Pesquisa Veterinária Brasileira 20(4):144-150. Depto Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brazil. Rabbits are susceptible to bovine herpesvirus type 5 (BHV-5) infection and often develop an acute and fatal neurological disease upon intranasal inoculation. The kinetics of viral infection of the central nervous system (CNS) was investigated by testing serial brain sections for infectivity at intervals after virus inoculation. The virus was first detected in the main olfactory bulb at 48h, followed by the olfactory cortex at 48/72h. At 72/96h infectivity was also detected in the trigeminal ganglia, pons and cerebral cortex. Two experiments were conducted to investigate the role of the olfactory system in the invasion of the rabbits’ CNS by BHV-5. In the first experiment, rabbits were inoculated with two BHV-5 isolates in the conjunctival sac. Rabbits inoculated by this route developed the neurological disease, yet with a reduced frequency and delayed clinical course. In a second experiment, twelve rabbits were submitted to surgical removal of the olfactory bulb and subsequently inoculated intranasally with BHV-5. Eleven out of 12 (91.6%) of the control rabbits developed the disease, against four out of 12 (33.3%) of the animals lacking the olfactory bulb. These results suggest that the olfactory system is the main pathway utilized by BHV-5 to reach the CNS of rabbits after intranasal inoculation. Nevertheless, the development of neurological infection in rabbits inoculated in the conjunctival sac and in rabbits lacking the olfactory bulb indicate that BHV- 5 may utilize an alternative route to invade the CNS, probably the sensory and autonomic fibers of the trigeminal nerve. The effects of immunization with homologous (BHV-5) and heterologous (BHV-1) strains in prevention of neurological disease by BHV-5 were investigated. Five out of 10 rabbits (50%) immunized with BHV-5 showed mild and transient neurological signs and one died upon challenge. Interestingly, the degree of protection against BHV-5 challenge was higher in rabbits immunized with BHV-1: only two rabbits showed transiente neurological signs and subsequently recovered. Thus, prevention of neurological disease by BHV-5 in rabbits may be achieved by immunization with either BHV-5 or BHV-1, likely reflecting the extensive serological cross-reactivity between these viruses. Further studies in rabbits may help in understanding the pathogenesis and immune response to BHV-5 infection.

• Bovine herpesvirus type 5 (BHV-5) meningo-encephalitis rabbits experimental model Herpesvírus Bovino tipo 5 meningoencefalite coelhos modelo experimental.

Abstract in Portuguese:

RESUMO.- Beltrão, N., Flores E.F., Weiblen R., Silva A.M., Roehe, P.M. & lrigoyen L.F. 2000. [Acute infection and neurological disease by bovine herpesvirus type-5 (BHV-5): Rabbits as an experimental model.] Infecção aguda e enfermidade neurológica pelo herpesvírus bovino tipo 5 (BHV-5): coelhos como modelo experimental. Pesquisa Veterinária Brasileira 20(4):144-150. Depto Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105- 900 Santa Maria, RS, Brazil. Coelhos são susceptíveis à infecção pelo herpesvírus bovino tipo 5 (BHV-5) e freqüentemente desenvolvem enfermidade neurológica aguda fatal após inoculação intranasal. A cinética da invasão do sistema nervoso central (SNC) de coelhos pelo BHV-5 foi estudada através de pesquisa de vírus em secções do SNC a diferentes intervalos pósinoculação. Após inoculação intranasal, o vírus foi inicialmente detectado no bulbo olfatório às 48h, seguido do córtex olfatório às 48/72h. Às 72/96h o vírus foi detectado também no gânglio trigêmeo, ponte e córtex cerebral. Dois experimentos foram realizados para avaliar a importância do sistema olfatório na invasão do SNC de coelhos pelo BHV-5. No primeiro experimento, coelhos foram inoculados com duas amostras do BHV-5 no saco conjuntival. Coelhos inoculados por essa via também desenvolveram a enfermidade neurológica, porém com menor freqüência com curso clínico tardio. No segundo experimento, doze coelhos foram submetidos à ablação cirúrgica do bulbo olfatório e posteriormente inoculados com o BHV-5 pela via intranasal. Onze de 12 coelhos controle (91,6%), não submetidos à cirurgia, desenvolveram a doença neurológica, contra quatro de 12 (33,3%) dos animais submetidos à remoção cirúrgica do bulbo olfatório. Esses resultados demonstram que o sistema olfatório constitui-se na principal via de acesso do BHV-5 ao encéfalo de coelhos após inoculação intranasal. No entanto, o desenvolvimento de infecção neurológica em coelhos inoculados pela via conjuntival e em coelhos sem o bulbo olfatório indica que o BHV-5 pode utilizar outras vias para invadir o SNC, provavelmente as. fibras sensoriais e autonômicas que compõe o nervo trigêmeo. Os efeitos da imunização com vírus homólogo (BHV-5) e heterólogo (BHV-1) na proteção à infecção neurológica foram investigados. Cinco entre 10 coelhos (50%) imunizados com o BHV-5 apresentaram sinais neurológicos discretos e transitórios e um morreu após o desafio com o BHV-5. Curiosamente, o grau de proteção foi superior nos coelhos imunizados com o BHV-1: apenas dois animais apresentaram sinais clínicos passageiros e recuperaram-se. Portanto, proteção da enfermidade neurológica pelo BHV-5 em coelhos pode ser obtida por imunização com o BHV-5 ou BHV-1, provavelmente devido à extensa reatividade sorológica cruzada entre esses vírus. Estudos adicionais em coelhos podem auxiliar no esclarecimento da patogênese e resposta imunológica a infecção pelo BHV-5.

Abstract in English:

ABSTRACT.- Brito M.F., França T.N., Oliveira K.D. & Cerqueira V.D. 2000. [Experiments in rabbits with cyanogenic plants.] Estudos experimentais em coelhos com plantas cianogênicas. Pesquisa Veterinária Brasileira 20(2):65-70. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23851-970, Brazil. The dried leaves of Piptadenia macrocarpa Benth. 1 =Anadenanthera macrocarpa (Benth.) Brenan], Piptadenia viridiflora (Kunth.) Benth. and Holocalyx glaziovii Taub. [=Holocalyx balansae Micheli], all trees of the Leguminosae Mimosoideae family, were given orally to rabbits in single doses. In the case of H. glaziovii, leaves were fed after being stored in two diferente ways. In the first series of experiments, Piptadenia macrocarpa failed to poison rabbits although the leaves were collected when sprouting, the most toxic stage forcattle. The experiments were performed 4 to 6 months after the leaves had been collected and dried. In a second series of experiments, similar leaves were fed at monthly intervals after harvest. They were toxic for the first 5 months, but were innocuous after 6 months storage. In both series of experiments the leaves were dried in the shade and then kept in cotton sacks at room temperature. They always were milled at the occasion of the experiments. These experiments with rabbits confirm the results with cattle, in which severe poisoning was caused by leaves stored for 3 months but caused no ili effect after 4 months, even when fed in large amounts. Young leaves of P. viridiflora were lethal at 12 g/kg, 12 months after collection and drying. In a second experiment the lethal dose was only 6 g/kg with leaves stored for only 2 months. These results show that the dried leaves of these species lose toxicity with time. Holocalyx glaziovii leaves were milled 6 weeks after collecting and dried and stored in sealed containers. They were fed in. single doses to different rabbits at intervals during a whole year. Lethal doses were initially 0.75 g/kg to 1.5 g/kg but rose to 1.5 g/kg to 3 g/kg by the end of the year. In a second experiment, leaves stored in cotton sacks and milled just before feeding were compared with milled leaves stored in sealed glass containers. The plant material kept in cotton sacks had halfthe toxicity of the leaves stored.for 2 months in sealed containers. After 10 to 12 months it was only a little less toxic than that stored in the sealed containers but there were no differences after 14 months. The symptoms observed in the rabbits that were poisoned by the dried leaves of P. macrocarpa, P. viridiflora and H. glaziovii were neuromuscular. Post-mortem findings and histopathological findings were almost absent. On opening the stomach, a strong smell of bitter almonds was sometimes noticed. The degree of toxicity during the storage of the dried leaves of he three tested plants was generallywell correlated with the picrate testfor cyanide.

• Poisonous plants experimental poisoning hydrocyanic poisoning Piptadenia macrocarpa Piptadenia anadenanthera Piptadenia viridiflora Holocalyx glaziovii Holocalyx balansae rabbits Plantas tóxicas intoxicação experimental intoxicação cianídrica coelhos.

Abstract in Portuguese:

RESUMO.- Brito M.F., França T.N., Oliveira K.D. & Cerqueira V.D. 2000. [Experiments in rabbits with cyanogenic plants.] Estudos experimentais em coelhos com plantas cianogênicas. Pesquisa Veterinária Brasileira 20(2):65-70. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23851-970, Brazil. A administração por via oral das folhas dessecadas de Piptadenia macrocarpa (Benth. [ =Anadenanthera macrocarpa (Benth.) Brenan], Piptadenia viridiflora (Kunth.) Benth. e Holocalyx glaziovii Taub. [ =Holocalyx balansae Micheli], plantas cianogênicas da família Leguminosae Mimosoideae, revelou a sensibilidade do coelho à elas, caracterizando-se a intoxicação por sintomatologia de natureza neuromuscular. A dose letal de P. macrocarpa foi de 6 g/kg para a brotação dessecada, até 5 meses após sua coleta; 6 meses depois da coleta a planta havia perdido a toxidez. A dose letal de P. viridiflora foi também de 6 g/kg para a brotação dessecada, coletada dois meses antes dos experimentos; 10 meses após a coleta a planta havia perdido metade da toxidez. Com H. glaziovii foram realizadas duas séries experimentais; estabeleceu-se a dose letal entre 0,75 e 1,5 g/kg com a planta coletada 2 meses antes, também com perda aproximada de metade da toxidez no período de 12 meses. O experimentos indicam, que H. glaziovii, moída logo após a coleta e armazenada em vidros fechados com tampa plástica, conserva melhor a toxidez nos primeiros meses do que a planta guardada em sacos de algodão, porém, ao final de um ano, essa diferença deixa de existir. A toxidez das folhas dessecadas foi proporcional à intensidade das reações das mesmas ao teste do papel picro-sódico, com raras exceções.

Abstract in English:

ABSTRACT.- Tokarnia C.H., GavaA., Brito M.F., Bezerra P.S. & Oliveira K.D. 1998. [Experimental poisoning in rabbits by Mascagnia sp (Malpighiaceae) collected in the State of Santa Catarina, southern Brazil.] Intoxicação experimental em coelhos por Mascagnia sp (Malpighiaceae) procedente do Estado de Santa Catarina. Pesquisa Veterinária Brasileira 18(2):61-64. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23851-970, Brazil. Freshly dried and ground young leaves or sprouts and mature leaves of Mascagnia sp, a creeping shrub of the Malpighiaceae family from Santa Catarina, known to be toxic to cattle, were suspended in water and given by gastric tube to adult rabbits. The rabbits showed first symptoms of poisoning between 3 hours and 24h49min after the beginning of feeding. The course of poisoning varied from 1 to 4 minutes. Symptoms consisted of generally violent incoordinated movements, followed by animals falling on their side, with dyspnea, slowing respiratory movements, a few final shrieks and death. The post-mortem findings were only hepatic congestion and splenomegaly. The lobulation of the liver was distinct; sometimes the centres of the lo bules were lighter in collor. Histopathology revealed regressive and circulatory alterations in the liver, kidneys and spleen. The lethal dose of the plant was very variable. The experiments did not allow to conclude if origin, growth stage or time of harvest influence its toxicity. The ground plant, kept in well closed recipients at room temperature for a year, was shown to have lost variable amounts of toxicity.

• Poisonous plants experimental poisoning Mascagnia sp Malpighiaceae rabbit Plantas tóxicas intoxicação experimental coelho.

Abstract in Portuguese:

RESUMO.- Tokarnia C.H., GavaA., Brito M.F., Bezerra P.S. & Oliveira K.D. 1998. [Experimental poisoning in rabbits by Mascagnia sp (Malpighiaceae) collected in the State of Santa Catarina, southern Brazil.] Intoxicação experimental em coelhos por Mascagnia sp (Malpighiaceae) procedente do Estado de Santa Catarina. Pesquisa Veterinária Brasileira 18(2):61-64. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23851-970, Brazil. As folhas novas ou a brotação e as folhas maduras de Mascagnia sp, arbusto escandente da família Malpighiaceae, procedente de Santa Catarina, planta comprovadamente tóxica a bovinos, foram administradas sob forma de pó suspenso em água por sonda gástrica, até poucas semanas após a sua colheita, a 45 coelhos adultos. A planta colhida em três municípios do Estado de Santa Catarina, dessecada na sombra a temperatura ambiente, demonstrou possuir toxidez também para essa espécie animal. Porém a sua toxidez para coelhos foi muito variável. Os experimentos realizados não permitem concluir que a procedência da planta, o seu estado de evolução ou a época do ano da colheita, sejam fatores que influenciam a sua toxidez. Já em relação ao quadro clínico, os achados de necropsia e histopatológicos, a planta teve um comportamento muito constante. Os coelhos mostraram os primeiros sintomas de intoxicação entre 3 horas e 24h49min após o começo da administração da planta. A evolução do quadro clínico foi de 1 a 4 minutos. Os sintomas consistiram sempre em que o animal subitamente começava a fazer movimentos desordenados, geralmente violentos; finalmente ficava caído, tinha respiração dispnéica com movimentos respiratórios cada vez mais espaçados, dava alguns gritos e logo morria. Os achados de necropsia se resumiram em congestão hepática e esplenomegalia; o fígado ao corte tinha a lobulação nítida, às vezes com o centro dos lóbulos mais claro. Os exames histopatológicos revelaram alterações regressivas e circulatórias no fígado, rim e baço. A planta moída guardada em vidros hermeticamente fechados com tampa plástica e à temperatura ambiente, submetida a experimentos em outros 22 coelhos 1 ano ou mais após sua colheita, demonstrou ter perdido variavelmente em toxidez.

Abstract in English:

The ground or whole seeds of Abrus precatoríus L., given by stomach tube in single doses to rabbits, caused a clinic-pathological picture of enteritis. The ground seeds caused death of all rabbits which received 0.03125 g/kg or more; doses of 0.015625 g/kg, 0.007812 g/kg and 0.003906 g/kg caused death of always one of three rabbits which received one of the doses. The dose of 0.001953 g/kg caused only slight symptoms in one of three rabbits tested; doses of 0.0009765 g/kg and 0.00048825 g/kg, each given to two rabbits, did not cause any symptoms. The whole seeds caused death of two rabbits which received the doses of 0.75 g/kg and 0.375 g/kg; doses of 0.25 g/kg and 0.125 g/kg, each one given to three rabbits, caused death of two from each group. The dose of 0.625 g/kg given to six rabbits, caused death only of one. The dose of 0.03125 g/kg did not cause any symptoms of poisoning in six rabbits. The period between the administration of the seeds and death varied from 13h35min to 7 days in the experiments with the ground seeds, and from 29hl 4min to 59h40min in the experiments with the whole seeds. The period between the administration of the seeds and recovery varied from 3 and a half days to 17 days in the experiments with the ground seeds and from 2 to 16 days in the experiments with the whole seeds. All 44 rabbits used in these experiments received the seeds only once. The clinic-pathological picture of the poisoning, which was the sarne in the experiments with the ground and the whole seeds of A.precatorius, consisted in inappetence/ anorexia, few faeces with bolus altered in form and size, sometimes dark coloured, soft or liquid, of foetid odor, with mucus and seldom with fibrina. There were manifestations of colic. The most important post-mortem changes were found in the small intestine and cecum. The former was distended by large amounts of liquid and mucous contents. Its wall was congested throughout its length and sometimes edematous, and fibrine covered the mucosa. The cecum was distended by soft to liquid contents and its wall showed congestion/hemorrhages and edema. The wall of the proximal colon was hemorrhagic and mucus was sometimes found in the lumen. In the rabbits which received the whole seeds, some of them were found in the stomach or rectum. In most rabbits slight to moderate splenomegaly was observed. The most important histological changes were seen in the digestive tract, mainly in the small intestine and less pronounced in the cecum. Few or no changes were observed in stomach and colon. The changes found in the different parts of the intestine were similar and consisted in coagulative necrosis of the mucosa with presence of nuclear fragments, congestion/hemorrhages of the mucosa, submucosa, muscularis and serosa, as well as edema of the submucosa. Additionally in the small intestine large amounts of nuclear fragments were seen in the upper portion of the lymphoid follicles and in smaller amounts in its center. In the appendix vermiformis, and in many cases also in the rudimentar cecum, variable amounts of nuclear fragments were seen in the stroma of the mucosa which resulted from necrosis by caryorhexis of macrophages of the lymphoid follicles, which migrated towards the intestinal lumen. In most rabbits thers was congestion of the spleen and mesenteric lymphnodes.

• Poisonous plants experimental plant poisoning Abrus precatorius Leguminosae Papilionoideae pathology rabbit

Abstract in Portuguese:

A administração por sonda intragástrica das sementes trituradas ou inteiras de Abrus precatorius L., em doses únicas, provocou em coelhos um quadro clínicopatológico grave de enterite. As sementes moídas causaram a morte de todos os coelhos a partir da dose de 0,03125 g/kg; as de 0,015625 g/kg, 0,0078125 g/kg e 0,003906 g/ kg causaram a morte, para cada uma dessas dosagens, de um de três coelhos. A dose de 0,001953 g/kg causou só sintomas leves em um de três coelhos e as de 0,0009765 g/kg e 0,00048825 g/kg não causaram sintomas nos dois coelhos para cada dosagem. As sementes inteiras causaram morte dos dois coelhos que receberam as doses de 0,75 g/kg e 0,375 g/kg; as de 0,25 e 0,125 g/kg causaram a morte, para cada uma dessas dosagens, de dois de três coelhos. A dose de 0,0625 g/kg causou a morte de um de seis coelhos. A dose de 0,03125 g/kg não causou sintomas de intoxicação em seis coelhos. O período entre a administração das sementes e a morte variou, nos experimentos com as sementes moídas, de 13h35min a 7 dias e nos experimentos com sementes inteiras, de 29h14min a 59h40min. O período entre a administração das sementes e a recuperação, variou, nos experimentos com as sementes moídas, de 3 e meio dias a 17 dias e nos experimentos com as sementes inteiras, de 2 a 16 dias. Todos os 44 coelhos usados nesses experimentos receberam as sementes de A. precatorius somente uma vez. O quadro clínico-patológico da intoxicação era o mesmo para a intoxicação pelas sementes moídas ou inteiras de A. precatorius. Os sintomas de intoxicação consistiram em inapetência/anorexia, fezes escassas e com forma e tamanho das síbalas alteradas, às vezes escuras, pastosas, líquidas, fétidas, com muco e raramente com fibrina. Havia sinais de cólica bem manifestos. Os achados de necropsia mais importantes ocorreram no intestino delgado e ceco. O intestino delgado estava muito dilatado com abundante conteúdo líquido-mucoso. Havia congestão da parede em toda extensão; às vezes edema. Fibrina revestia a mucosa. O ceco estava dilatado com conteúdo pastoso-líquido, a parede apresentava congestão/hemorragias e edema. No colon proximal às vezes havia muco na luz e homorragias na parede. Nos coelhos que receberam as sementes inteiras, algumas delas eram encontradas no estômago ou no rato. Na maioria dos coelhos havia ainda discreta a moderada esplenomegalia. As alterações histológicas mais importantes foram verificadas no tubo digestivo. Os segmentos mais afetados foram o intestino delgado e, com menor intensidade, o ceco. No estômago e colon as alterações foram poucas ou ausentes. As lesões nas diversas partes do intestino foram muito semelhantes e consistiram em necrose de coagulação da mucosa com presença de fragmentos nucleares, congestão/ hemorragias na mucosa, submucosa, muscular e serosa, e edema da submucosa. Na superfície dos folículos linfoides do intestino delgado observou-se grande quantidade de fragmentas nucleares; no interior desses folículos o grau de fragmentação era menor. No apêndice vermiforme e com menor frequência no ceco rudimentar, observou-se quantidade variável de fragmentos nucleares no estroma da mucosa, resultante da necrose por cariorrexia de macrófagos dos folículos linfóides que após ativação migraram em direção a luz intestinal. Na maioria dos coelhos havia ainda congestão do baço e dos linfonodos mesentéricos.

• Plantas tóxicas intoxicação experimental por plantas Abrus precatorius Leguminosae Papilionoideae patologia coelhos