PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

RESUMO.- Costa F.B., Alves F.R., Costa A.P., Barros A.C.E., Guerra P.C., Sousa A.L. & Oliveira A.S. 2009. Ultrasonographic and radiographic determination of egg development of jurarás (Kinosternon scorpioides) in captivity. [Determinação ultrassonográfica e radiográfica do desenvolvimento de ovos de jurarás em cativeiro.] Pesquisa Veterinária Brasileira 29(10):841-846. Departamento das Clínicas, Universidade Estadual do Maranhão, Cidade Universitária Paulo VI, Tirirical, Cx. Postal 9, São Luís, MA 65055-310, Brazil. E-mail: franc.borges@yahoo.com.br A tartaruga Kinosternon scorpioides (Linnaeus, 1766), com nome popular de jurará, é uma espécie bastante variável, e muitos nomes diferentes são atribuídos às suas populações, de acordo com sua localização geográfica. Atualmente, quatro subespécies foram validadas como K. scorpioides surgindo desde o extremo Sul do Panamá e norte da América do Sul, podendo ser encontradas ainda no Equador, no norte do Peru, sul da Bolívia, norte da Argentina, leste da Guiana e no Brasil. Desde modo, foi realizado um estudo ultrassonográfico e radiológico, a fim de descrever a morfologia e o desenvolvimento dos ovos de K. scorpioides em cativeiro, utilizando-se 20 fêmeas, no período de setembro de 2005 a agosto de 2006. No primeiro mês, o ciclo ovariano foi caracterizado pela ausência de folículos vitelogênicos, atrésicos ou presença de ovos em ovidutos. De outubro de 2005 a março de 2006 a varredura ultrassonográfica permitiu determinar o crescimento vitelogênico dos folículos, os quais foram observados com um formato que variou de ovóide a esférico, envolvidos por um conteúdo ecogênico, uma camada não-ecogência de albumina e uma casca de elevada ecogenicidade. Ovos presentes em ovidutos foram identificados por radiografias apenas 180 dias após início do experimento, quando a casca tornou-se suficientemente mineralizada para impressionar o filme radiográfico. Um transdutor linear de 7,5 MHz promoveu imagens com resolução e penetração adequada para visibilização de folículos. Exames ultrassonográficos sucessivos em fêmeas K. scorpioides permitiram determinar os estágios iniciais de desenvolvimento de folículos vitelogênicos e o exame radiográfico mostrou-se como técnica simples para avaliar a presença de ovos em ovidutos, permitindo fazer inferências sobre desenvolvimento de ovos em jurarás, a partir dos 6 meses de pós-observação por ultrassonografia.

• Kinosternon scorpioides jurará mud turtle wildlife conservation reproduction

Abstract in Portuguese:

ABSTRACT.- Costa F.B., Alves F.R., Costa A.P., Barros A.C.E, Guerra P.C., Sousa A.L. & Oliveira A.S. 2009. Ultrasonographic and radiographic determination of egg development of jurarás (Kinosternon scorpioides) in captivity. Pesquisa Veterinária Brasileira 29(10):841-846. Departamento das Clínicas, Universidade Estadual do Maranhão, Cidade Universitária Paulo VI, Tirirical, Cx. Postal 9, São Luís, MA 65055-310, Brazil. E-mail: franc.borges@yahoo.com.br Kinosternon scorpioides (Linnaeus, 1766), with its common name of jurará, is a quite variable species of turtles, and many different names have been applied to populations throughout its range. Currently, however, four subspecies are considered valid as K. scorpioides arises from southern Panama over most of northern South America and is found in Ecuador, northern Peru, southern Bolivia, northern Argentina, eastern Guyana and Brazil. Thus, an ultrasonographic and radiographic study was performed in order to describe the morphology and development of eggs of 20 female jurará mud turtles K. scorpioides, from September 2005 to August 2006. In the first month, the ovarian cycle was characterized by absence of vitellogenic follicles, atresic follicles or oviduct eggs. From October 2005 to March 2006 on, ultrasonographic scanning allowed to establish the growing vitellogenic follicles. Vitellogenic follicles were observed with spherical to ovoid shapes, with a surrounding echogenic yolk, a nonechogenic albumin layer, and a high echogenic shell. The oviduct eggs were identified by radiography just 180 days after beginning the experiment, when the shell became enough mineralized to impress the radiographic film. This experiment allowed to obtain by means of the 7.5 MHz linear probe images with adequate resolution and penetration for visualization of follicles. Successive ultrasonographic examinations of 20 K. scorpioides females allowed to access initial stages of vitellogenic follicles and oviduct eggs, and radiographic examination revealed to be an easy technique to assess oviduct eggs and to allow evaluation of egg development in jurarás, from 6 months on.

Abstract in English:

ABSTRACT.- Peixoto P.V., Nogueira V.A., Gonzaléz A.P., Tokarnia C.H. & França T.N. 2009. Accidental and experimental salinomycin poisoning in rabbits. Pesquisa Veterinária Brasileira 29(9):695-699. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br An outbreak of salinomycin poisoning in rabbits is described. At least 27 out of 2,000 rabbits reared on a farm died after the coccidiostatic drug sulfaquinoxaline was substituted by salinomycin in the feed. An average of 26.9ppm salinomycin was detected in the ration given to the rabbits. Clinical signs included anorexia, apathy and bradykinesia, which progressed to incoordination and recumbency. Gross lesions consisted of pale areas in the skeletal muscles. The histopathological findings showed severe necrotic degenerative myopathy in association with infiltration of neutrophils and macrophages. One rabbit exhibited similar alterations in the myocardium. Mineralization was observed in the affected skeletal muscles in some cases. In order to verify if the poisoning was due to salinomycin, 20 rabbits were divided into five groups and a ration containing the drug at doses of 10, 25, 50, 75 and 100ppm was given. The administration of doses higher than 50ppm resulted in manifestation of the clinical signs seen in the outbreak of poisoning. It was concluded, that probably an error related to the mixture of salinomycin in the feed was the cause of deaths in the spontaneous outbreak of poisoning on the rabbit farm.

• Salinomycin poisoning myopathy Salinomicina miopatia

Abstract in Portuguese:

RESUMO.- Peixoto P.V., Nogueira V.A., Gonzaléz A.P., Tokarnia C.H. & França T.N. 2009. Accidental and experimental salinomycin poisoning in rabbits. [Intoxicações natural e experimental por salinomicina em coelhos.] Pesquisa Veterinária Brasileira 29(9):695-699. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br Relata-se, pela primeira vez, um surto de intoxicação por salinomicina em coelhos. De 2000 animais, no mínimo 27 morreram após troca do coccidiostático sulfaquinoxalina pela salinomicina. A análise de parte da ração detectou 26,9ppm de salinomicina. Os sinais clínicos observados foram anorexia, apatia e lentidão com evolução para incoordenação dos movimentos e decúbito. As lesões macroscópicas consistiram de áreas pálidas na musculatura esquelética. O exame histopatológico evidenciou miopatia degenerativo-necrótica. Adicionalmente, verificou-se reação inflamatória constituída por neutrófilos e macrófagos. Um coelho apresentou lesões similares no miocárdio. Em alguns casos, mineralização estava presente nos músculos esqueléticos afetados. Vinte coelhos experimentais foram divididos em 5 grupos que receberam 10, 25, 50, 75 e 100ppm de salinomicina por via oral, com a finalidade de reproduzir a intoxicação. Os animais que receberam a partir de 50ppm de salinomicina apresentaram sinais clínicos semelhantes aos observados no surto espontâneo. Nossos resultados indicam que, provavelmente, erro na mistura da substância à ração causou a morte dos coelhos.

Abstract in English:

ABSTRACT.- Ispir U. 2009. Prophylactic effect of levamisole on rainbow trout (Oncorhynchus mykiss) against Yersinia ruckeri. Pesquisa Veterinária Brasileira 29(9):700-702. Faculty of Agriculture, Department of Fisheries, Bingol University, 23119 Bingol, Turkey. E-mail: uispir@yahoo.com Alteration in the relative percentage of survival (RPS) rate of rainbow trout (Oncorhynchus mykiss) exposed to 5, 10 and 25µg ml-1 levamisole for 2 h against Yersinia ruckeri was investigated. The average weight of the 120 fish used in this study was 6.3g. Upon challenge with a virulent strain, the relative survival percentage of respectively 83.3%, 86.7% and 76.6% was recorded. The results suggest that the application of levamisole in fish farms could increase resistance to infection of fish and offer economic benefits.

• Levamisole rainbow trout Oncorhynchus mykiss Yersinia ruckeri

Abstract in Portuguese:

Abstract in English:

ABSTRACT.- Nogueira V.A., França T.N. & Peixoto P.V. 2009. [Ionophore poisoning in animals.] Intoxicação por antibióticos ionóforos em animais. Pesquisa Veterinária Brasileira 29(3):191-197. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br The therapeutic use of ionophores in veterinary medicine has grown in the last years, with resultant increase in the risk of poisoning in animals. Ionophores are used as food additives as coccidiostacts in several animal species and growth promoter and bloat prevention in ruminants. The most often used ionophores are monensin, lasalocid, narasin and salinomycin. There is a great variation in the susceptibility to the toxic effect of ionophores in different animal species. Poisoning can occur when the dosage is too high or when not correct doses for a certain animal species are given. Cases of poisoning have been described in sheep, swine, horses, dogs and poultry. For horses ionophores are extremely toxic. The use of ionophores is only safe when used accordingly to the instructions of the manufacturer and especially for each animal species. In this paper the most important data regarding clinical-pathological and pathogenic aspects, and also the conditions in which the poisoning may occur are critically reviewed.

• Monensin lasalocid narasin salinomycin poisoning animals

Abstract in Portuguese:

ABSTRACT.- Nogueira V.A., França T.N. & Peixoto P.V. 2009. [Ionophore poisoning in animals.] Intoxicação por antibióticos ionóforos em animais. Pesquisa Veterinária Brasileira 29(3):191-197. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br The therapeutic use of ionophores in veterinary medicine has grown in the last years, with resultant increase in the risk of poisoning in animals. Ionophores are used as food additives as coccidiostacts in several animal species and growth promoter and bloat prevention in ruminants. The most often used ionophores are monensin, lasalocid, narasin and salinomycin. There is a great variation in the susceptibility to the toxic effect of ionophores in different animal species. Poisoning can occur when the dosage is too high or when not correct doses for a certain animal species are given. Cases of poisoning have been described in sheep, swine, horses, dogs and poultry. For horses ionophores are extremely toxic. The use of ionophores is only safe when used accordingly to the instructions of the manufacturer and especially for each animal species. In this paper the most important data regarding clinical-pathological and pathogenic aspects, and also the conditions in which the poisoning may occur are critically reviewed.

Abstract in English:

ABSTRACT.- Modolo J.R., Stachissini A.V.M., Gennari S.M., Dubey J.P., Langoni H., Padovani C.R., Barroso L. & Leite B.L.S. 2008. [Frequency of antibodies anti-Neospora caninum in sera of goats of the State São Paulo and its relationship with flock management.] Freqüência de anticorpos anti-Neospora caninum em soros de caprinos do estado de São Paulo e sua relação com o manejo dos animais. Pesquisa Veterinária Brasileira 28(12):597-600. Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Cx. Postal 524, Rubião Júnior s/n, Botucatu, SP 18618-000, Brazil. E-mail: jrmodolo@fmvz.unesp.br In order to assess the frequency of dairy goats seropositive for Neospora caninum in the state of São Paulo, and its relationship with age, sex, presence of dogs and reproductive problems in goat pens, serum samples were obtained from 923 goats of both sexes older than 3 months of age. Samples were collected in 17 properties located in different municipalities. Neospora agglutination test (NATe”25) was used to determine the presence of Neospora caninum in all animals. Epidemiological and reproductive data were obtained through a questionnaire which was administered in all goat pens. Significance level was set at 5% for all statistical tests. N. caninum positivity rate was 19.77%. Only one of the properties had no seropositive animal revealing N. caninum diffusion in the state. Seropositivity frequency did not correlate with sex, age, or reproductive problems. However, the presence of dogs was associated with a higher frequency of N. caninum seropositivity. A choroplethic map with hatch patterns showing the geographical distribution of goats seropositive for Neospora caninum may considerably contribute to geographic epidemiological studies and the development of disease control strategies.

• Neospora caninum occurrence; goats dogs epidemiological variables reproductive problems geographic distribution

Abstract in Portuguese:

ABSTRACT.- Modolo J.R., Stachissini A.V.M., Gennari S.M., Dubey J.P., Langoni H., Padovani C.R., Barroso L. & Leite B.L.S. 2008. [Frequency of antibodies anti-Neospora caninum in sera of goats of the State São Paulo and its relationship with flock management.] Freqüência de anticorpos anti-Neospora caninum em soros de caprinos do estado de São Paulo e sua relação com o manejo dos animais. Pesquisa Veterinária Brasileira 28(12):597-600. Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Cx. Postal 524, Rubião Júnior s/n, Botucatu, SP 18618-000, Brazil. E-mail: jrmodolo@fmvz.unesp.br In order to assess the frequency of dairy goats seropositive for Neospora caninum in the state of São Paulo, and its relationship with age, sex, presence of dogs and reproductive problems in goat pens, serum samples were obtained from 923 goats of both sexes older than 3 months of age. Samples were collected in 17 properties located in different municipalities. Neospora agglutination test (NATe”25) was used to determine the presence of Neospora caninum in all animals. Epidemiological and reproductive data were obtained through a questionnaire which was administered in all goat pens. Significance level was set at 5% for all statistical tests. N. caninum positivity rate was 19.77%. Only one of the properties had no seropositive animal revealing N. caninum diffusion in the state. Seropositivity frequency did not correlate with sex, age, or reproductive problems. However, the presence of dogs was associated with a higher frequency of N. caninum seropositivity. A choroplethic map with hatch patterns showing the geographical distribution of goats seropositive for Neospora caninum may considerably contribute to geographic epidemiological studies and the development of disease control strategies.

Abstract in English:

ABSTRACT.- Oliveira K.D., França T.N., Nogueira V.A. & Peixoto P.V. 2006. [Diseases associated with selenium poisoning in animals.] Enfermidades associadas à intoxicação por selênio em animais. Pesquisa Veterinária Brasileira 27(4):125-136. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: krishna.oliveira@uvv.br Trough a critical literature review, the main data of selenium poisoning in domestic animals are presented. Epidemiological, clinical, anatomic and histopathological aspects attributed to Alkali Disease, Blind Staggers, acute poisoning and focal symmetrical poliomielomalacia of swine are discussed. The main objective of the paper is to clarify obscure points of selenium poisoning, as well to point out the risks that supplementation with this element can represent.

• Selenium poisoning alkali disease blind staggers focal symmetrical poliomielomalacia

Abstract in Portuguese:

ABSTRACT.- Oliveira K.D., França T.N., Nogueira V.A. & Peixoto P.V. 2006. [Diseases associated with selenium poisoning in animals.] Enfermidades associadas à intoxicação por selênio em animais. Pesquisa Veterinária Brasileira 27(4):125-136. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: krishna.oliveira@uvv.br Trough a critical literature review, the main data of selenium poisoning in domestic animals are presented. Epidemiological, clinical, anatomic and histopathological aspects attributed to Alkali Disease, Blind Staggers, acute poisoning and focal symmetrical poliomielomalacia of swine are discussed. The main objective of the paper is to clarify obscure points of selenium poisoning, as well to point out the risks that supplementation with this element can represent.

Abstract in English:

ABSTRACT.- Jardim G.C., Pires P.P., Mathias L.A. & Ribeiro O.C. & Kuchembuck M.R.G. 2006. [Serological diagnosis of bovine brucellosis in adult herd vaccinated with Brucella abortus strain 19 reduced dose.] Diagnóstico sorológico da brucelose bovina em animais adultos vacinados com dose reduzida da cepa 19 de Brucella abortus. Pesquisa Veterinária Brasileira 26(3):177-182. Departamento de Medicina Veterinária, Universidade para o Desenvolvimento do Estado e Região do Pantanal (Uniderp), Rua Alexandre Herculano 1400, Parque dos Poderes, Campo Grande, MS 79037-280, Brazil. E-mail: gustavoj@mail.uniderp.br The study evaluated the use of a reduced dose of the Brucella abortus strain 19 vaccine, in an adult herd negative for the disease, by serological diagnostic techniques, advocated by the Brazilian Program for Animal Brucellosis and Tuberculosis Control and Eradication, and by an indirect ELISA. The complement fixation test detecteed 46.77% positives, the rose bengal test 67.74%, the mercaptoethanol with standard agglutination test 87.09% and the ELISA ID 100%. The reduced dose influenced the serological diagnosis. None of the techniques reached a suitable specificity for use in the herd under those conditions, up to 3 months after vaccination.

• Bovine brucellosis vaccination strain 19 serological diagnosis

Abstract in Portuguese:

ABSTRACT.- Jardim G.C., Pires P.P., Mathias L.A. & Ribeiro O.C. & Kuchembuck M.R.G. 2006. [Serological diagnosis of bovine brucellosis in adult herd vaccinated with Brucella abortus strain 19 reduced dose.] Diagnóstico sorológico da brucelose bovina em animais adultos vacinados com dose reduzida da cepa 19 de Brucella abortus. Pesquisa Veterinária Brasileira 26(3):177-182. Departamento de Medicina Veterinária, Universidade para o Desenvolvimento do Estado e Região do Pantanal (Uniderp), Rua Alexandre Herculano 1400, Parque dos Poderes, Campo Grande, MS 79037-280, Brazil. E-mail: gustavoj@mail.uniderp.br The study evaluated the use of a reduced dose of the Brucella abortus strain 19 vaccine, in an adult herd negative for the disease, by serological diagnostic techniques, advocated by the Brazilian Program for Animal Brucellosis and Tuberculosis Control and Eradication, and by an indirect ELISA. The complement fixation test detecteed 46.77% positives, the rose bengal test 67.74%, the mercaptoethanol with standard agglutination test 87.09% and the ELISA ID 100%. The reduced dose influenced the serological diagnosis. None of the techniques reached a suitable specificity for use in the herd under those conditions, up to 3 months after vaccination.

Abstract in English:

Hofer E. & Reis C.M.F. 2005. [Species and serovars of Listeria isolated from sick and clinically healthy animals in Brazil.] Espécies e sorovares de Listeria isolados de animais doentes e portadores no Brasil. Pesquisa Veterinária Brasileira 25(2):79-83. Laboratório de Zoonoses Bacterianas, Depto Bacteriologia, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, RJ 21045-900, Brazil. E-mail: ehofer@ioc.fiocruz.br Two hundred fourty-six strains of the genus Listeria were isolated from sick and clinically healthy animals, collected in three different regions of Brazil during 1971-2000. About 88.2% (217 cultures) yielded Listeria species from faecal specimens of healthy cattle and 29 strains (11.7%) were isolated from sick animals: 15 (6.0%) from central nervous system (CNS) and 14(5.6%) were from otherwise sterile sites. Phenotyping techniques were used to characterize the Listeria isolates. The commonest were L. innocua 6a and non-typable (140/56.9%), L. monocytogenes 4a (37/15.0%) and 4b (22/8.9%), originated mainly from stools of healthy cattle. From sick animals the predominant species and serovars were L. monocytogenes 4b (14/5.6%), and the higher incidence was observed in ruminants (12/4.8%) and 8/3.2% of the serovar 1a from other animal species (rodents and canines) mainly isolated from CNS samples.

• Listeria species serovars sick and healthy animals.

Abstract in Portuguese:

Hofer E. & Reis C.M.F. 2005. [Species and serovars of Listeria isolated from sick and clinically healthy animals in Brazil.] Espécies e sorovares de Listeria isolados de animais doentes e portadores no Brasil. Pesquisa Veterinária Brasileira 25(2):79-83. Laboratório de Zoonoses Bacterianas, Depto Bacteriologia, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, RJ 21045-900, Brazil. E-mail: ehofer@ioc.fiocruz.br Two hundred fourty-six strains of the genus Listeria were isolated from sick and clinically healthy animals, collected in three different regions of Brazil during 1971-2000. About 88.2% (217 cultures) yielded Listeria species from faecal specimens of healthy cattle and 29 strains (11.7%) were isolated from sick animals: 15 (6.0%) from central nervous system (CNS) and 14(5.6%) were from otherwise sterile sites. Phenotyping techniques were used to characterize the Listeria isolates. The commonest were L. innocua 6a and non-typable (140/56.9%), L. monocytogenes 4a (37/15.0%) and 4b (22/8.9%), originated mainly from stools of healthy cattle. From sick animals the predominant species and serovars were L. monocytogenes 4b (14/5.6%), and the higher incidence was observed in ruminants (12/4.8%) and 8/3.2% of the serovar 1a from other animal species (rodents and canines) mainly isolated from CNS samples.

Abstract in English:

ABSTRACT.- Araújo ER., Madruga C.R., Soares e.o. & Kessler R.H. 2003. [Progresses in immunization against Anaplasma marginale] Progressos na imunização contra Anaplasma marginale. Pesquisa Veterinária Brasileira23(3):139-148. Embrapa Gado de Corte, Cx. Postal 154, Campo Grande, MS 79002-970, Brazil. E-mail: flabio@cnpgc.embrapa.br The current immunization against anaplasmosis in cattle is derived from the blood of infected animais, as live or dead organisms. Nevertheless, efforts have been made to develop a new generation of vaccines. Toe outer membrane of Anaplasma marginale induces a protective immune response against challenge with homologous isolates and a partially protective response against heterologous challenge. ln this membrane, six major surface proteins (MSPs) have been identified, which · have been targeted for the development of immunogens against anaplasmosis. From those proteins, MSP1 a and MSP2 have shown the greatest potential as immunogens, protecting cattle against challenge with virulent homologous and heterologous isolates of A. marginale, despite the size polymorphism of the former protein and the variability of the gene that encodes the latter protein. Another alternative of immunogen is the in vitro culture of A. marginale. lnactivated organisms originating from Dermacentor variabilis IDE8 cell culture were tested as immunogen. Cattle immunized with cell culture-derived A. marginale had a significantly lower reduction in the packed cell volume after challenge exposure and did not display clinical anaplasmosis. Besides the protection afforded by this type of immunogen, cell culture derived organisms are free from bovine cells and pathogens, what is a major advantage as compared with traditional immunization procedures.

• Anaplasma marginale Ehrlichiae immunization bovine major surface proteins culture imunização bovino proteínas principais de superfície cultura.

Abstract in Portuguese:

RESUMO.- Araújo ER., Madruga C.R., Soares e.o. & Kessler R.H. 2003. [Progresses in immunization against Anaplasma marginale] Progressos na imunização contra Anaplasma marginale. Pesquisa Veterinária Brasileira23(3):139-148. Embrapa Gado de Corte, Cx. Postal 154, Campo Grande, MS 79002-970, Brazil. E-mail: flabio@cnpgc.embrapa.br Até o presente momento, as imunizações contra anaplasmose em rebanhos bovinos utilizam organismos vivos ou mortos. No entanto, esforços têm sido realizados nos últimos anos com o objetivo de desenvolver uma nova geração de vacinas. A membrana externa de Anaplasma marginale é capaz de induzir reposta imune protetora contra desafio homólogo e parcialmente protetora contra desafio heterólogo. Nela foram identificadas seis proteínas principais de superfície (MSPs), as quais têm sido alvo de estudos para o desenvolvimento de imunógenos contra a anaplasmose. Destas proteínas, MSPla e MSP2 têm demonstrado maior potencial como imunógenos, protegendo os animais contra desafio com isolados virulentos homólogos e heterólogos de A margina/e, apesar do polimorfismo de tamanho da primeira proteína e variabilidade do gene que codifica a segunda. Uma outra alternativa para a imunização contra A. margina/e é o cultivo in vitro dessa riquétsia. Organismos inativados provenientes de cultivo em células IDE8 de Dermacentor variabilis foram testados como imunógeno. Os animais apresentaram uma significativa diferença na redução do volume globular após desafio e não apresentaram sinais clínicos de anaplasmose. Além da proteção conferida por este tipo de imunógeno, os organismos provenientes de cultura de células de carrapato são livres de células. e patógenos de bovinos, o que é uma vantagem significativa quando comparado aos processos tradicionais de imunização.

Abstract in English:

ABSTRACT.- Bonel-Raposoj., Driemeier D., Barros S.S. & Gevehr~Fernandes C. 2003. [Histological and ultrastructural evolution of liver lesions in experimental Myoporum laetum poisoning of sheep and cattle.] Evolução das lesões histológicas e ultra-estruturais no fígado de ovinos e bovinos experimentalmente intoxicados por Myoporum laetum. Pesquisa Veterinária Brasileira 23(4):149-155. Depto Patologia Animal, Faculdade de Veterinária, UFPel, Pelotas, RS 96010-900, Brazil. E-mail: bonel-raposo@brturbo.com Green leaves of Myoporum laetum were collected during spring and summer, and administered to five sheep and six steers at dosages of 20 and 30 g/kg. Liver biopsies were taken before (Controls) and 1, 3 and 7 days after dosage. ln sheep, the clinicai signs were depression, rumen hypomotility, dried feces, tenesmus, teeth grinding, dyspnea and typical lesions of photosensitization. ln cattle, the clinicai picture was much less pronounced. The main histological findings in sheep were vacuolization of hepatocytes, portal ftbrosis, bile duct proliferation and necrosis of periportal hepatocytes; the ultrastructural examination revealed hyperplasia of the smooth endoplasmic reticulum, hepatocellular hydropic degeneration, presence of crystals and severa! other degenerative changes. ln cattle both, the histological and the ultrastructural findings, were less evident.

• Poisonous plants plant poisoning Myoporum laetum sheep cattle Plantas tóxicas intoxicação por plantas ovinos bovinos.

Abstract in Portuguese:

RESUMO.- Bonel-Raposoj., Driemeier D., Barros S.S. & Gevehr~Fernandes C. 2003. [Histological and ultrastructural evolution of liver lesions in experimental Myoporum laetum poisoning of sheep and cattle.] Evolução das lesões histológicas e ultra-estruturais no fígado de ovinos e bovinos experimentalmente intoxicados por Myoporum laetum. Pesquisa Veterinária Brasileira 23(4):149-155. Depto Patologia Animal, Faculdade de Veterinária, UFPel, Pelotas, RS 96010-900, Brazil. E-mail: bonel-raposo@brturbo.com Amostras de Myoporum laetum foram colhidas durante a primavera e verão e administradas a cinco ovinos e seis bovinos em doses únicas de 20 e 30 g/kg. Biópsias hepáticas foram colhidas antes (controles) e 1, 3 e 7 dias após a dosagem da planta. Estas biópsias foram analisadas histológica e ultraestruturalmente. Os sinais clínicos, em ovinos, caracterizaramse, especialmente; pordepressão, diminuição dos movimentos ruminais, fezes ressequidas, tenesmo, ranger de dentes, dispnéia e lesões típicas de fotossensibilização. Em bovinos, o quadro clínico foi discreto. Os principais achados histológicos, em ovinos, incluíram vacuolização de hepatócitos, fibrose portal, proliferação de duetos biliares e necrose de hepatócitos periportais. Os estudos ultra-estruturais, em ovinos, revelaram hiperplasia do retículo endoplasmático liso, tumefação de hepatócitos, degranulação e vesiculação do retículo endoplasmático rugoso, presença de cristais aciculares, retenção biliar, tumefação de mitocôndrias e várias outras alterações degenerativas. Em bovinos, tanto os achados histológicos, quanto os ultra-estruturais foram menos evidentes.