PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Vasconcelos J.S., Riet-Correa F., Dantas A.F.M., Medeiros R.M.T., Galiza G.J.N., Oliveira D.M. & Pessoa A.F.A. 2008. [Poisoning by Mascagnia rigida (Malpighiaceae) in sheep and goats.] Intoxicação por Mascagnia rigida (Malpighiaceae) em ovinos e caprinos. Pesquisa Veterinária Brasileira 28(10):521-526. Hospital Veterinário, CSTR, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail. franklin.riet@pq.cnpq.br Mascagnia rigida is the most important toxic plant for cattle in the Northeastern region of Brazil, causing sudden death during exercise. The objectives of this research were to report three outbreaks of poisoning by M. rigida in sheep and one in goats in the semiarid of the state of Paraíba, to reproduce experimentally the disease, and to determine if the active principle of the plant is eliminated through the milk. The outbreaks occurred at beginning of the raining season, when the plant sprouts ahead other forages, or after the end of the raining season, when M. rigida stayed green and other forages had dried. In the experimental reproduction of the poisoning doses of 10 and 20g of M. rigida per kg body weight from two different regions were lethal to 3 goats and 3 sheep. One goat that ingested 20g/kg and a sheep that ingested 10g/kg recovered. Two sheep and two goats that ingested 5g/kg had mild clinical signs and recovered. Clinical signs of experimental and spontaneous cases were ingurgitation of the jugular veins, reluctance to move, sternal recumbence, incoordination, respiratory distress, depression, instability, and muscular tremors. Death occurred after a clinical manifestation period of about 4 min to 27h40min. The main lesions were pulmonary edema and vacuolization and necrosis of epithelial cells in some renal tubules. To test if the active principle of M. rigida causes sudden deaths in newborn lambs and kids, 2g/kg of the plant were given daily to two goats and five sheep in the 15 days previous to parturition. One sheep aborted two lambs, 5 days before parturition. The four lambs of the other four sheep ingested the colostrum without problems. The kid from one goat ingested the colostrum and died suddenly 5 minutes after. The kid from the other goat died immediately after parturition before ingestion of colostrum. These results suggest that the active principle of M. rigida was eliminated through the milk at toxic doses for the kids. Management measures to prevent the poisoning are recommended.

• Toxic plants Mascagnia rigida Malpighiaceae sudden death fluoroacetic acid semiarid small ruminants

Abstract in Portuguese:

ABSTRACT.- Vasconcelos J.S., Riet-Correa F., Dantas A.F.M., Medeiros R.M.T., Galiza G.J.N., Oliveira D.M. & Pessoa A.F.A. 2008. [Poisoning by Mascagnia rigida (Malpighiaceae) in sheep and goats.] Intoxicação por Mascagnia rigida (Malpighiaceae) em ovinos e caprinos. Pesquisa Veterinária Brasileira 28(10):521-526. Hospital Veterinário, CSTR, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail. franklin.riet@pq.cnpq.br Mascagnia rigida is the most important toxic plant for cattle in the Northeastern region of Brazil, causing sudden death during exercise. The objectives of this research were to report three outbreaks of poisoning by M. rigida in sheep and one in goats in the semiarid of the state of Paraíba, to reproduce experimentally the disease, and to determine if the active principle of the plant is eliminated through the milk. The outbreaks occurred at beginning of the raining season, when the plant sprouts ahead other forages, or after the end of the raining season, when M. rigida stayed green and other forages had dried. In the experimental reproduction of the poisoning doses of 10 and 20g of M. rigida per kg body weight from two different regions were lethal to 3 goats and 3 sheep. One goat that ingested 20g/kg and a sheep that ingested 10g/kg recovered. Two sheep and two goats that ingested 5g/kg had mild clinical signs and recovered. Clinical signs of experimental and spontaneous cases were ingurgitation of the jugular veins, reluctance to move, sternal recumbence, incoordination, respiratory distress, depression, instability, and muscular tremors. Death occurred after a clinical manifestation period of about 4 min to 27h40min. The main lesions were pulmonary edema and vacuolization and necrosis of epithelial cells in some renal tubules. To test if the active principle of M. rigida causes sudden deaths in newborn lambs and kids, 2g/kg of the plant were given daily to two goats and five sheep in the 15 days previous to parturition. One sheep aborted two lambs, 5 days before parturition. The four lambs of the other four sheep ingested the colostrum without problems. The kid from one goat ingested the colostrum and died suddenly 5 minutes after. The kid from the other goat died immediately after parturition before ingestion of colostrum. These results suggest that the active principle of M. rigida was eliminated through the milk at toxic doses for the kids. Management measures to prevent the poisoning are recommended.

Abstract in English:

ABSTRACT.- Callado A.K.C., Castro R.S. & Teixeira M.F.S. 2001. [Lentiviruses of small ruminants (CAEV and Maedi-Visna): a review and perspectives] Lentivírus de pequenos ruminantes (CAEV e Maedi-Visna): revisão e perspectivas. Pesquisa Veterinária Brasileira 21(3):87-97. Depto Medicina Veterinária, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros s/n, Dois Irmãos, Recife, PE 55171-000, Brazil. E-mail: callado@altavista.net Small ruminant lentiviruses (SRLV), whose prototypes are Caprine Arthritis-Encephalitis virus (CAEV) and Maedi-Visna virus, are the causative agents of slow progressive degenerative diseases of goats and sheep (infected animals), responsible for significant economic losses. These viruses cause persistent infections with long periods of incubation and induce inflammatory and degenerative lesions. The lesions are induced in target organs of the host such as joints, CNS, lungs and mammary glands dueto viral replication in cells of the monocyte/macrophage lineage which is the main target cell. Infections occur particularly in the young and are acquired through ingestion of virus in milk or colostrum from infected does or ewes. The induction of immune response is variable and does not protect against the infection. Diagnosis is primarily based on the presence of SRLV antibodies usually detected by agar gel immunodiffusion (AGID) or enzyme linked immunosorbent assays (ELISA). As no vaccine is available, most often employed schemes to prevent spread of SRLV are based on segregation or/and culling of positive animals associated with management practices, especially the offspring. The strategies of SRLV for dealing with the immune system make difficult to accomplish diagnosis of infection, control or prevention of the viral spread. This review shows aspects of SRLV based on their phylogenetic studies of fields isolates, clinical, and immunopathological features.

• Small ruminant lentiviruses caprine arthritis-encephalitis virus maedi-visna retroviruses phylogenetic analysis epidemiology goat sheep Lentivírus de pequenos ruminantes vírus da artrite-encefalite caprina retrovírus análises filogenéticas epidemiologia caprino ovino.

Abstract in Portuguese:

RESUMO.- Callado A.K.C., Castro R.S. & Teixeira M.F.S. 2001. [Lentiviruses of small ruminants (CAEV and Maedi-Visna): a review and perspectives] Lentivírus de pequenos ruminantes (CAEV e Maedi-Visna): revisão e perspectivas. Pesquisa Veterinária Brasileira 21(3):87-97. Depto Medicina Veterinária, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros s/n, Dois Irmãos, Recife, PE 55171-000, Brazil. E-mail: callado@altavista.net Os lentivírus de pequenos ruminantes (SRLV), cujos protótipos são os vírus da Artrite-Encefalite Caprina (CAEV) e Maedi-Visna, são patógenos amplamente distribuidos, os quais causam doenças degenerativas progressivas lentas em caprinos e ovinos, determinando importantes perdas econômicas. Estes vírus causam infecções persistentes com período de incubação longo e causam inflamatórias e degenerativas. As lesões são induzidas em tecidos específicos do hospedeiro como articulações, pulmões, CNS e glândulas mamárias devido à replicação virai em células da linhagem monocítico-fagocitária que são as principais células-alvo. A infecção ocorre principalmente durante os primeiros meses de vida, através da ingestão de vírus no leite ou colostro de cabras ou ovelhas infectadas. A indução da resposta imunológica é variável e não protege contra a infecção. O diagnóstico é baseado primariamente na detecção de anticorpos para SRLV, geralmente por imunodifusão em gel de agar (AGID) e enzyme linked immunosorbent assay (ELISA). O diagnóstico e separação ou descarte dos animais soropositivos associado ao uso de certas práticas de manejo, especialmente das crias, são os principais meios implementados para prevenir a disseminação de SRLV, uma vez que ainda não existe vacina contra o vírus. As estratégias adotadas pelos SRLV para enfrentar o sistema imune dificultam o diagnóstico da infecção, controle ou prevenção da disseminação de SRLV. Esta revisão apresenta alguns aspectos das lentivíroses de pequenos ruminantes baseadas em estudos filogenéticos de amostras isoladas, aspectos clínicos e imunopatológicos.