PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Oliveira C.M.C., Barbosa J.D., Macedo R.S.C., Brito M.F., Peixoto P.V. & Tokarnia C.H. 2004. [A comparative study of the toxicity of Palicourea juruana (Rubiaceae) to buffalo and cattle.] Estudo comparativo da toxidez de Palicourea juruana (Rubiaceae) para búfalos e bovinos. Pesquisa Veterinária Brasileira 24(1):27-30. Escola de Medicina Veterinária, Campus Castanhal, Universidade Federal do Pará, Rua Maximino Porpino 1000, Castanhal, PA 68743-080, Brazil. E-mail: tokarnia@ufrrj.br An experimental study was performed to establish the toxicity of Palicourea juruana for buffaloes and to add new data on the toxicity of this plant for cattle. The clinical and pathological pictures were similar, but a comparison of the lethal doses for buffaloes (1-2g/kg) and cattle (0.25g/kg) shows that the buffalo is at least 4 times more resistant. In experiments performed 10 years earlier with the fresh leaves - collected on the same farm in July, at the beginning of the dry season, only 2 months later than in this second experimental series - the lethal dose for cattle was 2 g/kg. No explanation was found for the extremely high toxicity of the plant observed in the present study.

• Plant poisoning Palicourea juruana Rubiaceae cattle buffaloes.

Abstract in Portuguese:

Oliveira C.M.C., Barbosa J.D., Macedo R.S.C., Brito M.F., Peixoto P.V. & Tokarnia C.H. 2004. [A comparative study of the toxicity of Palicourea juruana (Rubiaceae) to buffalo and cattle.] Estudo comparativo da toxidez de Palicourea juruana (Rubiaceae) para búfalos e bovinos. Pesquisa Veterinária Brasileira 24(1):27-30. Escola de Medicina Veterinária, Campus Castanhal, Universidade Federal do Pará, Rua Maximino Porpino 1000, Castanhal, PA 68743-080, Brazil. E-mail: tokarnia@ufrrj.br An experimental study was performed to establish the toxicity of Palicourea juruana for buffaloes and to add new data on the toxicity of this plant for cattle. The clinical and pathological pictures were similar, but a comparison of the lethal doses for buffaloes (1-2g/kg) and cattle (0.25g/kg) shows that the buffalo is at least 4 times more resistant. In experiments performed 10 years earlier with the fresh leaves - collected on the same farm in July, at the beginning of the dry season, only 2 months later than in this second experimental series - the lethal dose for cattle was 2 g/kg. No explanation was found for the extremely high toxicity of the plant observed in the present study.

Abstract in English:

Nobre V.M.T., Riet-Correa F., Barbosa Filho J.M., Dantas A.F.M., Tabosa I.M. & Vasconcelos J.S. 2004. [Poisoning by Crotalaria retusa (Fabaceae) in Equidae in the semiarid region of Paraíba.] Intoxicação por Crotalaria retusa (Fabaceae) em eqüídeos no semi-árido da Paraíba. Pesquisa Veterinária Brasileira 24(3):132-143. Depto Clínicas Veteri-nárias, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: verônica.nobre@uol.com.br From 2000 to 2003 eight cases of poisoning by Crotalaria retusa L. were observed in horses on 8 farms in the semiarid region of Paraíba and Ceará. C. retusa was found in all farms. The main clinical signs were characteristic of hepatic encephalopathy, with dullness or hyperexcitability, head pressing, compulsive walking or circling and, occasionally, violent uncontrollable galloping. Decreased cranial nerve reflexes, ataxia and weakness were also observed. Other clinical signs were anorexia, weight loss, photosensitization and jaundice. The clinical manifestation period varied from 4 to 40 days, but most horses had a previous history of weight loss. At necropsy the livers were hard, with irregular surface and white areas mixed with dark red areas and increased lobular pattern. Mild jaundice, ascitis, hydropericardium and hydrothorax were also observed. Edema and moderate congestion were seen in the lungs. Histologic changes of the liver were characterized by fibrosis, mainly periportal, megalocitosis and bile duct cell proliferation. Multifocal areas of centrilobular or midzonal hemorrhages were also observed. Centrilobular hemorrhagic necrosis was present in two horses. Alzheimer type II astrocytes were observed, isolated or in groups, mainly in the caudate nucleus and cortex in 4 horses. The poisoning was experimentally produced in 1 adult horse and 3 adult donkeys. The horse received daily 100 g of C. retusa seeds and died 52 days after the beginning of the experiment. The dried whole C. retusa was mixed with grass and given to the 3 experimental donkeys at daily doses of 10g/kg, 5g/kg and 2.5g/kg, respectively. The donkey treated with 5g per kg died 48 days after beginning of the experiment and the other two were sacrificed at 120 days. Clinical signs and pathology were similar to those observed in spontaneous cases, but Alhzeimer type II astrocytes were observed only in the donkey that died 48 days after the beginning of ingestion of the plant material. The concentration of monocrotaline in the whole plant given to the donkeys was 0.5%.

• Poisonous plants plant poisoning Crotalaria retusa Fabaceae hepatic cirrhosis horse pirrolizidine alkaloids.

Abstract in Portuguese:

Nobre V.M.T., Riet-Correa F., Barbosa Filho J.M., Dantas A.F.M., Tabosa I.M. & Vasconcelos J.S. 2004. [Poisoning by Crotalaria retusa (Fabaceae) in Equidae in the semiarid region of Paraíba.] Intoxicação por Crotalaria retusa (Fabaceae) em eqüídeos no semi-árido da Paraíba. Pesquisa Veterinária Brasileira 24(3):132-143. Depto Clínicas Veteri-nárias, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: verônica.nobre@uol.com.br From 2000 to 2003 eight cases of poisoning by Crotalaria retusa L. were observed in horses on 8 farms in the semiarid region of Paraíba and Ceará. C. retusa was found in all farms. The main clinical signs were characteristic of hepatic encephalopathy, with dullness or hyperexcitability, head pressing, compulsive walking or circling and, occasionally, violent uncontrollable galloping. Decreased cranial nerve reflexes, ataxia and weakness were also observed. Other clinical signs were anorexia, weight loss, photosensitization and jaundice. The clinical manifestation period varied from 4 to 40 days, but most horses had a previous history of weight loss. At necropsy the livers were hard, with irregular surface and white areas mixed with dark red areas and increased lobular pattern. Mild jaundice, ascitis, hydropericardium and hydrothorax were also observed. Edema and moderate congestion were seen in the lungs. Histologic changes of the liver were characterized by fibrosis, mainly periportal, megalocitosis and bile duct cell proliferation. Multifocal areas of centrilobular or midzonal hemorrhages were also observed. Centrilobular hemorrhagic necrosis was present in two horses. Alzheimer type II astrocytes were observed, isolated or in groups, mainly in the caudate nucleus and cortex in 4 horses. The poisoning was experimentally produced in 1 adult horse and 3 adult donkeys. The horse received daily 100 g of C. retusa seeds and died 52 days after the beginning of the experiment. The dried whole C. retusa was mixed with grass and given to the 3 experimental donkeys at daily doses of 10g/kg, 5g/kg and 2.5g/kg, respectively. The donkey treated with 5g per kg died 48 days after beginning of the experiment and the other two were sacrificed at 120 days. Clinical signs and pathology were similar to those observed in spontaneous cases, but Alhzeimer type II astrocytes were observed only in the donkey that died 48 days after the beginning of ingestion of the plant material. The concentration of monocrotaline in the whole plant given to the donkeys was 0.5%.

Abstract in English:

Brito M.F., Tokarnia C.H. & Döbereiner J. 2004. [The toxicity of diverse lantanas for cattle and sheep in Brazil.] A toxidez de diversas lantanas para bovinos e ovinos no Brasil. Pesquisa Veterinária Brasileira 24(3):153-159. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23890-000, Brazil. E-mail: tokarnia@ufrrj.br Experiments on the toxicity of Lantana spp for cattle and sheep revealed a similar situation as is reported from Australia. Neither all Lantana species nor all varieties which occur in Brazil are poisonous. Lantana samples collected at Boa Vista (Roraima), Castanhal (Pará), Cáceres (Mato Grosso), Serra Talhada (Pernambuco), Cabo Frio and Quatis (Rio de Janeiro), and Canoinhas (Santa Catarina) were toxic. All the other Lantana samples, collected at Cruzeiro do Sul (Acre), Castanhal (Pará), Chapada dos Guimarães and Lambari d’Oeste (Mato Grosso), Jaguaribe (Ceará), Vitória da Conquista and Wanderley (Bahia), Vitória (Espírito Santo), Vassouras, Parati and Itaguaí (Rio de Janeiro) revealed experimentally as non-toxic at a dose of 40g/kg. In all cases the lethal dose was 40 g/kg, with two exceptions: the sample collected at Canoinha (Santa Catarina) was much more toxic (10g/kg) and the one from Serra Talhada (Pernambuco) was much less toxic, as this last sample caused lethal poisoning only at a dosage of 40g/kg/day given during 30 days. Histories about the observation of photosensitization in cattle due to the ingestion of Lantana spp were obtained at Serra Talhada (Pernambuco), Cáceres (Mato Grosso), Cabo Frio and Quatis (Rio de Janeiro), and Canoinhas (Santa Catarina). No correlation could be established between the colour of the flowers of Lantana spp and the toxicity of the plants. This confirms reports from Australia that the toxic potential of the Lantana species is not necessarily related to the colour of their flowers.

• Poisonous plants plant poisoning Lantana spp Verbenaceae sheep cattle pathology.

Abstract in Portuguese:

Brito M.F., Tokarnia C.H. & Döbereiner J. 2004. [The toxicity of diverse lantanas for cattle and sheep in Brazil.] A toxidez de diversas lantanas para bovinos e ovinos no Brasil. Pesquisa Veterinária Brasileira 24(3):153-159. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, RJ 23890-000, Brazil. E-mail: tokarnia@ufrrj.br Experiments on the toxicity of Lantana spp for cattle and sheep revealed a similar situation as is reported from Australia. Neither all Lantana species nor all varieties which occur in Brazil are poisonous. Lantana samples collected at Boa Vista (Roraima), Castanhal (Pará), Cáceres (Mato Grosso), Serra Talhada (Pernambuco), Cabo Frio and Quatis (Rio de Janeiro), and Canoinhas (Santa Catarina) were toxic. All the other Lantana samples, collected at Cruzeiro do Sul (Acre), Castanhal (Pará), Chapada dos Guimarães and Lambari d’Oeste (Mato Grosso), Jaguaribe (Ceará), Vitória da Conquista and Wanderley (Bahia), Vitória (Espírito Santo), Vassouras, Parati and Itaguaí (Rio de Janeiro) revealed experimentally as non-toxic at a dose of 40g/kg. In all cases the lethal dose was 40 g/kg, with two exceptions: the sample collected at Canoinha (Santa Catarina) was much more toxic (10g/kg) and the one from Serra Talhada (Pernambuco) was much less toxic, as this last sample caused lethal poisoning only at a dosage of 40g/kg/day given during 30 days. Histories about the observation of photosensitization in cattle due to the ingestion of Lantana spp were obtained at Serra Talhada (Pernambuco), Cáceres (Mato Grosso), Cabo Frio and Quatis (Rio de Janeiro), and Canoinhas (Santa Catarina). No correlation could be established between the colour of the flowers of Lantana spp and the toxicity of the plants. This confirms reports from Australia that the toxic potential of the Lantana species is not necessarily related to the colour of their flowers.

Abstract in English:

Colodel E.M., Seitz A.L., Schmitz M., Borba M.R., Raymundo D.L. & Driemeier D. 2004. [Poisoning by Erythroxylum deciduum (Erythroxylaceae) in sheep.] Intoxicação por Erythroxylum deciduum (Erythroxylaceae) em ovinos. Pesquisa Veterinária Brasileira 24(3):165-168. Setor de Patologia Veterinária, Depto Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E- mail: moleta@terra.com.br. The epidemiological, clinical and pathological aspects of natural poisoning caused by Erythroxylum deciduum fruits in sheep are reported. The outbreak occurred from January to March of 2004, in Lagoa Vermelha county, state of Rio Grande do Sul, Brazil. The poisoning was experimentally reproduced by oral administration of E. deciduum fruits to 5 sheep.Three of them developed neurological signs and died. Poisoning was caused with a single dose of 60g/kg or when the dosage was fractioned into at least 4 doses of 17 g/kg given every 12 hours. The main clinical signs in natural and experimentally poisoned sheep were ataxia, hyperexcitability and muscular tremors which where more pronounced when the animals were moved. At the final stage, dyspnea with abdominal breathing and cyanosis was observed. The most significant alterations found at necropsy were pronounced edema, lung congestion and presence of the fruits or seeds of E. deciduum in the ruminal content of all animals. Histologically, except edema and pulmonary congestion, there were no other significant changes observed.

• Poisonous plants plant poisoning experimental plant poisoning Erythroxylum deciduum Erythroxylaceae sheep.

Abstract in Portuguese:

Colodel E.M., Seitz A.L., Schmitz M., Borba M.R., Raymundo D.L. & Driemeier D. 2004. [Poisoning by Erythroxylum deciduum (Erythroxylaceae) in sheep.] Intoxicação por Erythroxylum deciduum (Erythroxylaceae) em ovinos. Pesquisa Veterinária Brasileira 24(3):165-168. Setor de Patologia Veterinária, Depto Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E- mail: moleta@terra.com.br. The epidemiological, clinical and pathological aspects of natural poisoning caused by Erythroxylum deciduum fruits in sheep are reported. The outbreak occurred from January to March of 2004, in Lagoa Vermelha county, state of Rio Grande do Sul, Brazil. The poisoning was experimentally reproduced by oral administration of E. deciduum fruits to 5 sheep.Three of them developed neurological signs and died. Poisoning was caused with a single dose of 60g/kg or when the dosage was fractioned into at least 4 doses of 17 g/kg given every 12 hours. The main clinical signs in natural and experimentally poisoned sheep were ataxia, hyperexcitability and muscular tremors which where more pronounced when the animals were moved. At the final stage, dyspnea with abdominal breathing and cyanosis was observed. The most significant alterations found at necropsy were pronounced edema, lung congestion and presence of the fruits or seeds of E. deciduum in the ruminal content of all animals. Histologically, except edema and pulmonary congestion, there were no other significant changes observed.

Abstract in English:

Rech R.R, Fighera R.A., Oliveira F.N. & Barros C.S.L. 2004. [Granulomatous meningoencephalitis in cattle grazing vetch (Vicia spp).] Meningoencefalite granulomatosa em bovinos em pastoreio de ervilhaca (Vicia spp). Pesquisa Veterinária Brasileira 24(3): 169-172. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Granulomatous meningoencephalitis was observed in 7 out of 8 adult dairy cows affected by vetch-associated systemic granulomatous disease, although there was no neurological signs associated with the condition. The cellular inflammatory infiltrates were located in the leptomeninges and as perivascular cuffings within the brain and consisted of epithelioid macrophages, lymphocytes, plasm cells and eosinophils. These inflammatory changes varied from mild to severe from animal to animal and among different brain regions of the same animal. Perivascular cuffings were usually more marked than the leptomeningeal infiltrates. Affected brain regions, in decreasing order of intensity, included diencephalon through the level of massa intermedia, mesencephalon at the level of rostral colliculi, pons and cerebellar peduncles, medulla at the level of obex, frontal lobe at the level of the genu of the corpus callosum, and cerebellum. The character and the distribution of the inflammatory changes are emphasized regarding the differential diagnosis with other diseases and lesions of the bovine central nervous system in the context of the Brazilian surveillance program for bovine spongiform encephalopath.

• Diseases of cattle diseases of the central nervous system meningoencephalitis plant poisoning Vicia spp pathology.

Abstract in Portuguese:

Rech R.R, Fighera R.A., Oliveira F.N. & Barros C.S.L. 2004. [Granulomatous meningoencephalitis in cattle grazing vetch (Vicia spp).] Meningoencefalite granulomatosa em bovinos em pastoreio de ervilhaca (Vicia spp). Pesquisa Veterinária Brasileira 24(3): 169-172. Depto Patologia, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: claudioslbarros@uol.com.br Granulomatous meningoencephalitis was observed in 7 out of 8 adult dairy cows affected by vetch-associated systemic granulomatous disease, although there was no neurological signs associated with the condition. The cellular inflammatory infiltrates were located in the leptomeninges and as perivascular cuffings within the brain and consisted of epithelioid macrophages, lymphocytes, plasm cells and eosinophils. These inflammatory changes varied from mild to severe from animal to animal and among different brain regions of the same animal. Perivascular cuffings were usually more marked than the leptomeningeal infiltrates. Affected brain regions, in decreasing order of intensity, included diencephalon through the level of massa intermedia, mesencephalon at the level of rostral colliculi, pons and cerebellar peduncles, medulla at the level of obex, frontal lobe at the level of the genu of the corpus callosum, and cerebellum. The character and the distribution of the inflammatory changes are emphasized regarding the differential diagnosis with other diseases and lesions of the bovine central nervous system in the context of the Brazilian surveillance program for bovine spongiform encephalopath.

Abstract in English:

Tokarnia C.H., Barbosa J.D., Oliveira C.M.C., Brito M.F., Oliveira R.B. & Barbas L.A. 2004. [Comparative epidemiological, clinical and pathological aspects of poisoning by Arrabidaea bilabiata (Bignoniaceae) in buffalo and cattle.] Aspectos epidemiológicos e clínico-patológicos comparados da intoxicação por Arrabidaea bilabiata (Bignoniaceae) em búfalos e bovinos. Pesquisa Veterinária Brasileira 24(2):74-79. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, Rio de Janeiro 23890-000, Brazil. E-mail: tokarnia@ufrrj.br Experiments showed that the clinical and pathological pictures were essentially the same, but the buffalo was at least twice more resistant than the bovine to the toxic effect of Arrabidaea bilabiata (Sprague) Sandw. It was also shown that the young leaves are twice (October, end of the dry season) or one and a half (May, end of the rainy season) more toxic than the mature leaves, and that the plant is more toxic in October. These data indicate that the smaller incidence of poisoning by plants of the group that causes sudden death in buffaloes in the Amazon Region is, in part, due to the greater resistance of this animal species to the toxic action of the plant. Also important seems to be the coincidence of the preferential habitat of the buffalo (flooded areas) with the habitat of A. bilabiata, less toxic than Palicourea marcgravii St.Hil. which is a plant of the non-flooded areas, the preferential habitat of cattle.

• Plant poisoning Arrabidaea bilabiata Bignoniaceae toxicity buffalo cattle.

Abstract in Portuguese:

Tokarnia C.H., Barbosa J.D., Oliveira C.M.C., Brito M.F., Oliveira R.B. & Barbas L.A. 2004. [Comparative epidemiological, clinical and pathological aspects of poisoning by Arrabidaea bilabiata (Bignoniaceae) in buffalo and cattle.] Aspectos epidemiológicos e clínico-patológicos comparados da intoxicação por Arrabidaea bilabiata (Bignoniaceae) em búfalos e bovinos. Pesquisa Veterinária Brasileira 24(2):74-79. Projeto Sanidade Animal Embrapa/UFRRJ, Km 47, Seropédica, Rio de Janeiro 23890-000, Brazil. E-mail: tokarnia@ufrrj.br Experiments showed that the clinical and pathological pictures were essentially the same, but the buffalo was at least twice more resistant than the bovine to the toxic effect of Arrabidaea bilabiata (Sprague) Sandw. It was also shown that the young leaves are twice (October, end of the dry season) or one and a half (May, end of the rainy season) more toxic than the mature leaves, and that the plant is more toxic in October. These data indicate that the smaller incidence of poisoning by plants of the group that causes sudden death in buffaloes in the Amazon Region is, in part, due to the greater resistance of this animal species to the toxic action of the plant. Also important seems to be the coincidence of the preferential habitat of the buffalo (flooded areas) with the habitat of A. bilabiata, less toxic than Palicourea marcgravii St.Hil. which is a plant of the non-flooded areas, the preferential habitat of cattle.

Abstract in English:

Cattani C.S.O., Colodel E.M., Traverso S.D., Correa A.M.R., & Driemeier D. 2004. [Experimental poisoning by Dodonea viscosa (Sapindaceae) in cattle.] Intoxicação experimental por Dodonea viscosa (Sapindaceae) em bovinos. Pesquisa Veterinária Brasileira 24(1):31-34. Depto Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Bairro Agronomia, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: moleta@terra.com.br The leaves of Dodonea viscosa were force fed to five bovines. Four received the leaves in fresh green stage and the fifth dried ones. Clinical signs were observed in four of the bovines that died; the fifth did not show signs of poisoning. The fresh green plant was proved to be toxic from a dose of 25g/kg on. Dried leaves fed at the dose of 30 g/kg were also toxic. All the animals that died showed clinical signs from 13h30min to 45h after the ingestion of the plant and and death followed within about 48h. The clinical course lasted for about 8h30min until death. The main symptoms where apathy, anorexia, slight tenesmus, muscle trembling, difficulties to keep consciousness, pressing the head against obstacles, lateral recumbency, paddling movements, coma and death. The most significant macroscopic alterations were observed in the liver, with accentuation of the lobular pattern, dark-red areas interspersed with yellowish areas. Petechiae were found in serosal membranes of the abdominal and thoracic organs as well as the intestines. The main microscopic change was hepatic centrolobular coagulative necrosis, associated with congestion and hemorrhages.

• Dodonea viscosa diseases of cattle plant poisoning hepatocellular necrosis.

Abstract in Portuguese:

Cattani C.S.O., Colodel E.M., Traverso S.D., Correa A.M.R., & Driemeier D. 2004. [Experimental poisoning by Dodonea viscosa (Sapindaceae) in cattle.] Intoxicação experimental por Dodonea viscosa (Sapindaceae) em bovinos. Pesquisa Veterinária Brasileira 24(1):31-34. Depto Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Bairro Agronomia, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: moleta@terra.com.br The leaves of Dodonea viscosa were force fed to five bovines. Four received the leaves in fresh green stage and the fifth dried ones. Clinical signs were observed in four of the bovines that died; the fifth did not show signs of poisoning. The fresh green plant was proved to be toxic from a dose of 25g/kg on. Dried leaves fed at the dose of 30 g/kg were also toxic. All the animals that died showed clinical signs from 13h30min to 45h after the ingestion of the plant and and death followed within about 48h. The clinical course lasted for about 8h30min until death. The main symptoms where apathy, anorexia, slight tenesmus, muscle trembling, difficulties to keep consciousness, pressing the head against obstacles, lateral recumbency, paddling movements, coma and death. The most significant macroscopic alterations were observed in the liver, with accentuation of the lobular pattern, dark-red areas interspersed with yellowish areas. Petechiae were found in serosal membranes of the abdominal and thoracic organs as well as the intestines. The main microscopic change was hepatic centrolobular coagulative necrosis, associated with congestion and hemorrhages.

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.

Abstract in English:

ABSTRACT.- Barbosa]. D., Oliveira C. M. C., Tokarnia C. H. & Riet-Correa E 2003. [Comparison of the sensibility of cattle and buffaloes to poisoning by Palicourea marcgravii (Rubiaceae).] Comparação da sensibilidade de bovinos e búfalos à intoxicação por Palicourea marcgravii (Rubiaceae). Pesquisa Veterinária Brasileira 23(4): 167-172. Escola de Medicina Veterinária, Campus Castanhal, Universidade Federal do Pará, Rua Maximino Porpino 1000, Castanhal, PA 68743- 080, Brazil. E-mail: diomedes@ufpa.br In order to verify if buffaloes are more resistant than cattle to poisoning by Palicourea marcgravii, the plant was given per os simultaneously to buffaloes and cattle. Seven buffaloes and three head of cattle were used. Doses of 0.5, 1.0 and 2.0 g/kg did not cause signs of poisoning in buffaloes; but doses of 3.0, 4.0 and 6.0 g/kg caused death. In cattle 0.25 g/kg did not cause symptoms; but 0.5 and 2.0 g/kg were lethal. The influence of exercise on the onset of symptoms, the time which elapsed from the beginning of the administration of the plant to the appearance of symptoms, and the symptoms themselves, were similar in the two animal species. The clinical course was longer in buffaloes; whilst in cattle the period between the onset of severe symptoms and death lasted 9 to 17 minutes; in buffaloes it varied from 10 minutes to 1 hour 28 minutes. It can be concluded, that buffaloes are about six times more resistant than cattle to the toxic action of P. maracgravii. The lower incidence of deaths in buffaloes by poisonous plants in the Amazon region is, at least in part, due the lower sensibility of buffaloes to poisoning by this plant. Another factor responsible for the smaller number of buffaloes which die due to plant poisoning in the Amazon region, is possibly that buffaloes prefer the Jowlands, e.g. temporarily flooded areas, which are the habitat of Arrabidaea bilabiata, the second most important poisonous plant of the Amazon region. This plant is less poisonous than P. marcgravii, and its habitat are the higher not flooded areas. So it would be safer, in order to diminish losses, to breed buffaloes instead of cattle in areas where P. marcgravii occurs. The reason for the greater resistance of buffaloes should be further investigated as a possible prophylactic measure to avoid poisoning by P. marcgravii in cattle. On the other hand, Australian investigators modified genetically the ruminai bacteria Butyrivibrio fibrisolvens by introducing a gene, isolated from a Moraxella sp, which codifies a dehalogenase, capable of hydrolyzing fluoroacetate, the poisonous principle of P. marcgravii. Transferring the genetically modified B. fibrisolvens into the rumen of animal, which consume plants that contain fluoroacetate, would be a viable method to control that poisoning through a ruminal detoxifying process for the toxin. Through preliminary contacts, the director of the consorcium in Australia, responsible for the modification of the bacteria, declared that he is interested to sell the technology to our country, but it would be necessary to know if it is permitted to introduce into Brazil the genetically modified bacteria. If allowed, it would be necessary to perform investigations on the viability and the methodology for using this bacteria to control P. marcgravii poisoning in our country.

• Poisonous plants plant poisoning Palicourea marcgravii Rubiaceae cattle buffaloes prophylaxis Butyrivibrio fibrisolvens genetically modified bactéria Intoxicação por planta Rubiaceae bovinos búfalos profilaxia bactérias geneticamente modificadas.

Abstract in Portuguese:

RESUMO.- Barbosa]. D., Oliveira C. M. C., Tokarnia C. H. & Riet-Correa E 2003. [Comparison of the sensibility of cattle and buffaloes to poisoning by Palicourea marcgravii (Rubiaceae).] Comparação da sensibilidade de bovinos e búfalos à intoxicação por Palicourea marcgravii (Rubiaceae). Pesquisa Veterinária Brasileira 23(4): 167-172. Escola de Medicina Veterinária, Campus Castanhal, Universidade Federal do Pará, Rua Maximino Porpino 1000, Castanhal, PA 68743- 080, Brazil. E-mail: diomedes@ufpa.br O presente estudo foi realizado para verificar se búfalos são mais resistentes do que bovinos à ação tóxica de Palicourea marcgravii, mediante a administração da planta por via oral, simultaneamente, a bovinos e a búfalos. Foram usados sete búfalos e três bovinos. Verificou-se que em búfalos doses de 0,5 g/kg, 1,0 g/kg e 2,0 g/kg não causaram sintomas de intoxicação. As doses de 3,0 g/kg, 4,0 g/kg e 6,0 g/kg causaram a morte dos búfalos. Em bovinos, a dose de 0,25g/kg não causou sinais clínicos de intoxicação, enquanto que doses de 0,5 g/kg e 2,0 g/kg causaram a morte. A influência do exercício sobre o aparecimento dos sintomas, o prazo decorrido desde o começo da administração da planta até o início de sintomas, e os próprios sintomas, foram semelhantes nas duas espécies animais. O curso clínico foi mais longo nos búfalos. Enquanto nos bovinos o período entre o aparecimento dos sintomas graves e a morte foi de 9 a 17 minutos, nos búfalos variou de 10 minutos a 1 hora e 28 minutos. Pode se concluir que os bubalinos são aproximadamente seis vezes mais resistentes do que os bovinos à ação tóxica de P. marcgravii. O menor índice de mortes pela ação de plantas tóxicas na Amazônia em búfalos é, pelo menos em parte, devido à maior resistência do búfalo à intoxicação por essa planta. Outro fator responsável pelo menor número de mortes em búfalos pela intoxicação por plantas, na Amazônia, poderia ser que os búfalos preferem a várzea, que é o habitat de Arrabidaea bilabiata, a segunda planta tóxica mais importante da Amazônia, menos tóxica do que P. marcgravii, e com habitat na terra firme. Em áreas onde ocorre P. marcgravii seria mais prudente, para diminuir os prejuízos, criar búfalos em lugar de bovinos. A causa dessa maior resistência do búfalo merece ser investigada para a eventual elaboração de métodos profiláticos da intoxicação por P. marcgravii em bovinos. Por outro lado, pesquisadores australianos modificaram geneticamente a bactéria ruminal Butyrivibrio fibrisolvens, mediante a introdução de um gene, isolado de Moraxella sp, que codifica uma dehalogenase, capaz de hidro-lizar fluoroacetato. A transferência de B.fibrisolvens geneticamente modificado para o rúmen de animais ingerindo plantas que contêm fluoroacetato, como é o caso de P. marcgravii, seria um método viável para o controle da intoxicação mediante a detoxificação ruminal do princípio ativo. Em contatos preliminares o diretor responsável do consórcio na Austrália responsável pela modificação da bactéria, declarou o interesse em vender a tecnologia ao nosso país, porém seria necessário saber se é possível importar essa bactéria geneticamente modificada no Brasil. Caso positivo, seria indispensável realizar pesquisas sobre a viabilidade e a metodologia para o uso dessa bactéria em nosso meio.

Abstract in English:

ABSTRACT.- Traverso S.D., Corrêa A.M.R., Pescador C.A., Colodel E.M., Cruz C.E.F. & Driemeier D. 2002. [Experimental poisoning by Trema micrantha (Ulmaceae) in goats.) Intoxicação experimental por Trema micrantha (Ulmaceae) em caprinos. Pesquisa Veterinária Brasileira 22(4):141-147. Setor de Patologia Veterinária, Depto Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@vortex.ufrgs.br Green leaves of Trema micrantha were ground and mixed with water in a domestic blender and then administered by stomach tube to seven goats. One additional goat was fed ad libidum with the green leaves of T. micrantha. Clinical signs were observed in six goats that became ill 2 days after having been dosed with or fed the plant. There were five deaths, which occurred until 4 days after ingestion. Affected goats remained static during long periods and kept their heads low. Incoordination, rhythmical movements of the head, apathy, anorexia, and tenesmos were also noticed. Paddling movements and coma were seen in one goat. T. micrantha was toxic at dosages of 30 g/kg or higher. The most significant gross lesions were observed in the livers, which were yellowish, friable, and with pronounced lobular pattern. Their cut surfaces were reddened and depressed areas alternated with whitish ones. The tiver of one goat was slightly but homogeneously reddened but did not show accentuated lobulation. Petechial haemorrhages in the region between the chest and scapula, in the epicardium, mediastinum and serosal membranes of the abdominal organs were also observed. The most importante histologic finding was hepatic centrilobular coagulative necrosis, which was associated with congestion, haemorrhages and degenerative changes in the circumjacent hepatocytes. Additional microscopic lesions were found in the nervous system and included perineuronal and perivascular edema and swollen neurones, especially those of the frontal cortex.

• Poisonous plants plant poisoning Trema micrantha Ulmaceae goats Plantas tóxicas intoxicação por plantas caprinos.

Abstract in Portuguese:

RESUMO.- Traverso S.D., Corrêa A.M.R., Pescador C.A., Colodel E.M., Cruz C.E.F. & Driemeier D. 2002. [Experimental poisoning by Trema micrantha (Ulmaceae) in goats.) Intoxicação experimental por Trema micrantha (Ulmaceae) em caprinos. Pesquisa Veterinária Brasileira 22(4):141-147. Setor de Patologia Veterinária, Depto Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9090, Cx. Postal 15094, Porto Alegre, RS 91540-000, Brazil. E-mail: davetpat@vortex.ufrgs.br Sete caprinos receberam, por sonda esofágica, uma suspensão aquosa de folhas verdes de Trema micrantha moídas e um outro recebeu folhas verdes da planta à vontade. Os sinais clínicos iniciaram-se 2 dias após a ingestão e ocorreram em seis caprinos, cinco dos quais morreram em até 4 dias. Os animais doentes permaneciam longos períodos em estação, com cabeça baixa, olhar fixo, apáticos e inapetentes. Tenesmo, incoordenação e movimentos rítmicos laterais da cabeça também foram observados. T. micrantha mostrou-se tóxica a partir de 30g/kg de peso corporal. A alteração macroscópica mais significativa foi observada no fígado, que se apresentou friável, amarelado e com acentuado padrão lobular. Ao corte, havia áreas vermelhas, deprimidas e entremeadas por áreas mais claras. Em um animal, a coloração do fígado era vermelha, homogênea, mais clara que o normal e sem evidenciação do padrão lobular. Petéquias foram constatadas entre a escápula e o esterno, no epicárdio, no mediastino e nas serosas dos órgãos da cavidade abdominal. A principal alteração histológica foi necrose coagulativa centrolobular que, em alguns casos, atingia todo o lóbulo, associada à congestão, hemorragia e alterações degenerativas nos hepatócitos circunjacentes. No sistema nervoso, havia tume fação de neurônios, mais proeminente no córtex frontal, associado a edema perineuronal e perivascular.