Cenurose em ovino com sinais neurológicos - diagnóstico com tomografia computadorizada / Cenurosis in a sheep with neurological signs - diagnosis with computed tomography

Background: Cenurosis is a parasitic disease caused by Coenurus cerebralis, an intermediate form of Taenia multiceps multiceps, causing a fatal disease in production animals. Its adult form (Taenia) lodges in the small intestine of canids and can infect several intermediate hosts. Sheep are the main species affected by the disease, having nervous symptoms as one of its manifestations. This study aimed to describe the changes observed in computed tomography, as well as the clinical findings of a case of Cenurosis in a sheep on the western border of Rio Grande do Sul. Case: A ram was referred to the Centro Universitário da Região da Campanha (URCAMP) with neurological signs. Clinical, hematological, radiographic, tomographic and necroscopic evaluation of the animal was performed. There were no significant hematological and radiographic changes. During the neurological examination, corneal opacity was found in the right eyeball, associated with a visual deficit in the same eye. Also, when stimulated to move, it was possible to observe ataxia with ambulation to the left side, with right lateral displacement of the head. The tomography showed a hypodense area of approximately 3 cm at the base of the brain, in the region of the thalamus and third ventricle. Macroscopically, a translucent spherical cyst with approximately 4 cm in diameter was observed, containing the protoescolex/scolices of Taenia multiceps in the same region. Discussion: Computed tomography identified the presence of an apparently circular volume of approximately 4 cm in diameter, causing ventricular dilatation. This evidence of ventricular dilation corroborates aspects described in the literature, which found bilateral dilation of the ventricles by compression promoted by a cyst in the 4th ventricle. As the location of the cyst was located at the base of the brain, in the region of the third ventricle, it would be difficult to perform the surgery in the treatment of this case. Signs of ataxia, walking movements, decreased reflexes, nystagmus, unilateral blindness and lateral decubitus are commonly observed. Reports described that the main neurological alterations observed in 20 sheep with cenurosis were postural deficit, locomotion alteration, visual deficit and behavioral alterations, with more than 50% of the animals showing at least one of these signs. The main neurological signs observed in the case described were changes in gait, with walking, blindness, lateral head deviation and ataxia. These signs guide the clinical diagnosis of cenurosis. At necropsy, a spherical translucent cyst with approximately 4 cm in diameter was observed, containing the protoescolex/scolices of Taenia multiceps, which extended dorsally from the third ventricle to the base of the thalamus, laterally displaced to the right side. Rostrocaudal the lesion extended rostrally across the entire length of the thalamus to the beginning of the caudate nucleus and caudally to the base of the caudal colliculus, causing compression of the adjacent parenchyma, enabling the diagnosis of cenurosis. Similar findings are described as Coenurus cerebralis. This lesion pattern macroscopically characterizes the parasite lesions. Thus, it is concluded that the visualization of a hypodense area in CNS regions of sheep with neurological signs allows the diagnosis of cenurosis and precise location of the lesion. The description of this case adds information so that other professionals in the field can be successful in diagnosing the disease.

Molecular phylogenetic analysis of Cysticercus ovis from Egypt based on MT-CO1 gene sequences / Análise filogenética molecular de Cysticercus ovis do Egito com base nas sequências do gene MT-CO1

Cysticercus ovis or sheep measles is the larval stage of Taenia ovis, which is the intestinal tapeworm of dogs. It is found in the cardiac and skeletal muscles of sheep and can be the cause of partial or total condemnation of carcasses at abattoirs. The aim of the current work was to determine the prevalence of C. ovis among sheep in Upper Egypt and to present the molecular and phylogenetic analysis of this using the amplified Mitochondrial Cytochrome Oxidase subunit 1 (MT-CO1) gene. A total of 1885 sheep slaughtered at local abattoirs of 4 different governorates of Upper Egypt (Asuit, Sohag, Qena and Aswan) were carefully examined for C. ovis. The overall prevalence of infection was 2.02%. The highest rate of infection was observed in adult animals over 4 years of age (44.73%). There was no significant effect of animal sex on infection rates. The phylogenic analysis of C. ovis Egyptian isolates showed very close similarity to the New Zealand isolate (AB731675). This is the first report showing the genetic analysis of C. ovis in Egypt, which provides a very powerful tool for taxonomy and definitive diagnosis of C. ovis, which could be helpful for preventive and control programs.(AU)

Cysticercus ovis sheep measles é o estágio larval da Taenia ovis, encontrada nos músculos de carneiros, causado pela ingestão de ovos de Taenia ovis, parasita de cães. O objetivo do presente trabalho foi determinar a prevalência de C. ovis entre ovinos no Alto Egito e apresentar as análises moleculares e filogenéticas, utilizando o gene da subunidade mitocondrial citocromo-oxidase amplificada 1 (MT-CO1). Um total de 1885 ovinos abatidos em matadouros locais de 4 províncias diferentes do Alto Egito (Asuit, Sohag, Qena e Aswan) foram cuidadosamente examinados para C. ovis. A prevalência geral de infecção foi de 2,02%. A maior taxa de infecção foi observada em animais adultos com mais de 4 anos de idade (44,73%). Não houve efeito significativo do sexo nas taxas de infecção. A análise filogenética de isolados egípcios de C. ovis mostrou uma similaridade muito próxima ao isolado da Nova Zelândia (AB731675). Este é o primeiro relato mostrando a análise genética de C. ovis no Egito, fornecendo uma ferramenta para taxonomia e diagnóstico definitivo de C. ovis, podendo ser útil para programas preventivo e de controle.(AU)

Caracterização das lesões parasitárias de ovinos observadas na linha de abate / Characterization of parasitic lesions of sheep observed at slaughter line

Considerando a possibilidade de erros na identificação das lesões e a necessidade de melhorar o diagnóstico, o objetivo desse trabalho foi caracterizar macroscopicamente e microscopicamente as principais lesões parasitárias observadas em ovinos na linha de abate. Os materiais foram colhidos durante duas visitas a um matadouro frigorífico de ovinos no estado do Rio Grande do Sul. Totalizaram-se 161 amostras com lesões parasitárias de ovinos em diferentes órgãos. As alterações observadas incluíam hidatidose, cisticercose por Cysticercus ovis, cisticercose por Cysticercus tenuicollis, sarcocistose (morfologia compatível com Sarcocystis gigantea), fasciolose (Fasciola hepatica) e esofagostomose. Das 161 amostras, 25,5% correspondiam a hidatidose, e os cistos hidáticos foram observados, predominantemente, nos pulmões (46,3%) e fígado (41,5%). Ao corte, os cistos demonstraram três padrões morfológicos: cistos uniloculares viáveis (34%); cistos multivesiculares viáveis (31,7%); e cistos hidáticos (uniloculares e multivesiculares) degenerados (34%). As lesões de cisticercose por C. ovis (22,4%) foram visualizadas no coração (63,9%), língua (13,9%), músculo masseter (11,1%) e diafragma (11,1%). Morfologicamente os cisticercos foram classificados em vivos (viáveis), degenerados e mineralizados. Lesões provocadas por S. gigantea (19,2%) estavam presentes na túnica muscular do esôfago, na língua e na laringe. Macroscopicamente, observaram-se múltiplas estruturas nodulares brancas que continham uma cápsula fibrosa e lúmen preenchido por material gelatinoso translúcido. Cisticercose por C. tenuicollis representaram 18,6% das lesões. Os cistos foram observados aderidos no omento, no mesentério, na cápsula do fígado e na vesícula biliar. Morfologicamente os cistos foram classificados como vivos (viáveis) e degenerados. Os cistos vivos apresentavam a parede translúcida ou levemente opaca, contendo um escólex no seu interior. Os cistos degenerados eram brancacentos, firmes, com espessa cápsula fibrosa e centro mineralizado. Lesões provocadas por F. hepatica corresponderam a 7,4% dos casos. As lesões hepáticas caracterizavam-se macroscopicamente por espessamento variável dos ductos biliares por fibrose e ocasionalmente havia exemplares de F. hepatica no lúmen dos ductos. Em oito casos, observaram-se áreas de acentuada necrose do parênquima hepático. Lesões provocadas por Oesophagostomum spp. perfizeram 6,8% dos casos. As alterações foram observadas no intestino delgado e intestino grosso de todos os ovinos e em dois casos, havia também envolvimento dos linfonodos mesentéricos. Nos intestinos, as lesões caracterizavam-se por nódulos bem delimitados, salientes na serosa, firmes e que invadiam também a camada muscular. Nos linfonodos havia obliteração do parênquima nodal por acentuada mineralização. É extremamente importante a identificação morfológica das diferentes lesões parasitárias encontradas nas linhas de abate em frigoríficos de ovinos, para posterior destino correto das mesmas. As alterações devem ser avaliadas com o intuito principal de reconhecer a sua capacidade infecciosa. Além disso, é fundamental o conhecimento dos locais anatômicos mais comuns em que cada alteração geralmente costuma ocorrer.(AU)

Considering the possibilities of mistaken diagnoses in identifying lesions at meat inspection this study was designed to provide data for a better-educated diagnosis by the meat inspectors through the gross and microscopic characterization of parasitic lesions observed in slaughtered sheep at the inspection line. One hundred and sixty-one samples of parasitic lesions were sampled from various organs of slaughtered sheep during two visits to a sheep abattoir located in the state of Rio Grande do Sul, Brazil. Lesions observed included hydatid cysts, cysticercosis due to Cysticercus ovis and to Cysticercus tenuicollis, sarcocystosis (morphology compatible with Sarcocystis gigantea), fasciolosis (Fasciola hepatica) and oesophagostomosis. Twenty-five point five percent of the 161 samples corresponded to hydatidosis and the hydatid cysts were observed predominantly in the lungs (46.3%) and liver (41.5%). On cut surface, the cysts had three different morphological patterns: viable unilocular cysts (34%); viable multivesicular cysts (31.7%); and degenerate (unilocular and multivesicular) hydatid cysts (34%). Cysticercosis by C. ovis (22.4%) was observed in the myocardium (63.9%), tongue (13.9%), masseter (11.1%), and diaphragm (11.1%). Morphologically the cysticerci were classified as viable, degenerated or mineralized. Lesions caused by S. Gigantea (19.2%) were observed in the muscle layer of the esophagus, tongue, and larynx. Grossly there were multiple white nodular structures that contained a fibrous capsule with the lumen filled by translucent and gelatinous material. Cysticercosis by C. tenuicollis accounted for 18.6% of observed parasitic lesions; the cysts adhered to the omentum, mesentery, liver capsule, and serosal surface of gall bladder; grossly the cysts were classified as viable and degenerated. Viable cysts had translucent or slightly opaque walls and contained a single scolex. Degenerated cysts were white, firm and with a thick fibrous capsule and mineralized center. Lesions caused by F. hepatica accounted for 7.4% of the cases and were grossly characterized by variable fibrous thickening of bile ducts which occasionally contained the adult flukes in their lumina. In eight cases there were marked areas of necrosis in the hepatic parenchyma. Lesions caused Oesophagostomumspp. accounted for 6.8% of the observed parasitic cases and the changes were observed in all cases in the walls of the small and large intestine; in two cases mesenteric lymph nodes were also involved. In the intestines, lesions were characterized by firm well-circumscribed nodules prominent in the serosal surface and also invading the muscle layer. In the lymph nodes marked mineralization obliterated the nodal parenchyma. The correct identification of the various parasitic lesions found in the viscera of sheep in the abattoir inspection line it is important to dictate the proper destination of affected organs and carcasses. The lesions should be evaluated aiming to determine their infective capacity and to acquire knowledge about their more frequent anatomical sites.(AU)

Caracterização das lesões parasitárias de ovinos observadas na linha de abate / Characterization of parasitic lesions of sheep observed at slaughter line

Considerando a possibilidade de erros na identificação das lesões e a necessidade de melhorar o diagnóstico, o objetivo desse trabalho foi caracterizar macroscopicamente e microscopicamente as principais lesões parasitárias observadas em ovinos na linha de abate. Os materiais foram colhidos durante duas visitas a um matadouro frigorífico de ovinos no estado do Rio Grande do Sul. Totalizaram-se 161 amostras com lesões parasitárias de ovinos em diferentes órgãos. As alterações observadas incluíam hidatidose, cisticercose por Cysticercus ovis, cisticercose por Cysticercus tenuicollis, sarcocistose (morfologia compatível com Sarcocystis gigantea), fasciolose (Fasciola hepatica) e esofagostomose. Das 161 amostras, 25,5% correspondiam a hidatidose, e os cistos hidáticos foram observados, predominantemente, nos pulmões (46,3%) e fígado (41,5%). Ao corte, os cistos demonstraram três padrões morfológicos: cistos uniloculares viáveis (34%); cistos multivesiculares viáveis (31,7%); e cistos hidáticos (uniloculares e multivesiculares) degenerados (34%). As lesões de cisticercose por C. ovis (22,4%) foram visualizadas no coração (63,9%), língua (13,9%), músculo masseter (11,1%) e diafragma (11,1%). Morfologicamente os cisticercos foram classificados em vivos (viáveis), degenerados e mineralizados. Lesões provocadas por S. gigantea (19,2%) estavam presentes na túnica muscular do esôfago, na língua e na laringe. Macroscopicamente, observaram-se múltiplas estruturas nodulares brancas que continham uma cápsula fibrosa e lúmen preenchido por material gelatinoso translúcido. Cisticercose por C. tenuicollis representaram 18,6% das lesões. Os cistos foram observados aderidos no omento, no mesentério, na cápsula do fígado e na vesícula biliar. Morfologicamente os cistos foram classificados como vivos (viáveis) e degenerados. Os cistos vivos apresentavam a parede translúcida ou levemente opaca, contendo um escólex no seu interior.(AU)

Considering the possibilities of mistaken diagnoses in identifying lesions at meat inspection this study was designed to provide data for a better-educated diagnosis by the meat inspectors through the gross and microscopic characterization of parasitic lesions observed in slaughtered sheep at the inspection line. One hundred and sixty-one samples of parasitic lesions were sampled from various organs of slaughtered sheep during two visits to a sheep abattoir located in the state of Rio Grande do Sul, Brazil. Lesions observed included hydatid cysts, cysticercosis due to Cysticercus ovis and to Cysticercus tenuicollis, sarcocystosis (morphology compatible with Sarcocystis gigantea), fasciolosis (Fasciola hepatica) and oesophagostomosis. Twenty-five point five percent of the 161 samples corresponded to hydatidosis and the hydatid cysts were observed predominantly in the lungs (46.3%) and liver (41.5%). On cut surface, the cysts had three different morphological patterns: viable unilocular cysts (34%); viable multivesicular cysts (31.7%); and degenerate (unilocular and multivesicular) hydatid cysts (34%). Cysticercosis by C. ovis (22.4%) was observed in the myocardium (63.9%), tongue (13.9%), masseter (11.1%), and diaphragm (11.1%). Morphologically the cysticerci were classified as viable, degenerated or mineralized. Lesions caused by S. Gigantea (19.2%) were observed in the muscle layer of the esophagus, tongue, and larynx. Grossly there were multiple white nodular structures that contained a fibrous capsule with the lumen filled by translucent and gelatinous material. Cysticercosis by C. tenuicollis accounted for 18.6% of observed parasitic lesions; the cysts adhered to the omentum, mesentery, liver capsule, and serosal surface of gall bladder; grossly the cysts were classified as viable and degenerated. Viable cysts had translucent or slightly opaque walls and contained a single scolex.(AU)

Prevalence and risk factors for Cysticercus tenuicollis in goats and sheep in Paraíba, northeastern Brazil / Prevalência e fatores de risco para Cysticercus tenuicollis em caprinos e ovinos na Paraíba, Nordeste do Brasil

This study aimed to determine the prevalence and risk factors for C. tenuicollis among goats and sheep in slaughterhouses in Paraíba. 390 animals (195 goats and 195 sheep) in the municipalities of Patos and Esperança, Paraíba, Brazil, were inspected between February and May 2014. The prevalence of C. tenuicollis was 39% (76/195) in goats and 17.4% (34/195) in sheep. In both species, most of the cysticerci vesicles were located at the omentum and mesentery. The only risk factor found was extensive sheep farming. It can be concluded that C. tenuicollis is highly prevalent in small ruminants in Paraíba, being more prevalent in goats than in sheep. Extensively-reared sheep were twice as likely to develop infection by this parasite.(AU)

Objetivou-se determinar a prevalência e os fatores de riscos de C. tenuicollis em caprinos e ovinos nos matadouros da Paraíba. Foram inspecionados 390 animais (195 caprinos e 195 ovinos) nos municípios de Patos e Esperança, Paraíba, Brasil, no período de Fevereiro a Maio de 2014. A prevalência de C. tenuicollis em caprinos foi de 39% (76/195) e em ovinos de 17,4% (34/195). Os locais mais acometidos por C. tenuicollis nas duas espécies foram o omento e o mesentério. O único fator de risco encontrado foi a produção extensiva de ovinos. Pode-se concluir que é alta a prevalência de C. tenuicollis em pequenos ruminantes no Estado da Paraíba, sendo mais prevalente na espécie caprina; e que ovinos criados de forma extensiva apresentam duas vezes mais riscos de contrais a infecção por este parasita.(AU)

Monitoring of parasitic cysts in the brains of a flock of sheep in Egypt / Monitoramento de cistos parasitários no cérebro de um rebanho de ovinos no Egito

Cerebral parasitic cysts constitute a major problem for livestock. Among these, coenurosis and toxoplasmosis are predominant. Here, a total number of 60 sheep obtained from a private farm in Suez province, Egypt, were examined postmortem to detect visible parasitic cysts, and microscopically to detect small-sized entities. Necropsy revealed bladder-like cysts measuring 0.5-6.5 cm in diameter that were filled with a translucent fluid containing a large number of protoscolices. Accordingly, the cysts were identified as the metacestode Coenurus cerebralis. Among the sheep examined, 11 animals (7 males and 4 females) (18.3%) were infected. Most of the cysts were located in the cerebral hemispheres, with numbers ranging from one to three per infected animal. The effect of the presence of cysts in the brain tissue was evaluated. Histopathologically, pseudocysts of the apicomplexan Toxoplasma gondii were found in two animals with no detectable inflammatory cell reactions. In conclusion, coenurosis and toxoplasmosis are serious parasitic problems that play a significant role in sheep management in Egypt, as a result of close contact between livestock and dogs and cats, which play a critical role in the life cycle of these parasites.

Cistos cerebrais parasitários constituem um grande problema para o gado. Entre estes, coenurosis e toxoplasmose são predominantes. Aqui, um número total de 60 ovelhas obtidas em uma fazenda particular na província Suez, Egito, foram examinadas post-mortem para a detecção de cistos parasitários visíveis e microscopicamente para detectar cistos de pequenas dimensões. A necropsia revelou cistos medindo entre 0,5-6,5 cm de diâmetro, preenchidos com um fluido transparente, contendo um grande número de protoscolices. Por conseguinte, os cistos foram identificados como o metacestóide Coenurus cerebralis. Entre as ovelhas examinadas, 11 animais (7 machos e 4 fêmeas) (18,3%) estavam infectados. A maior parte dos cistos estavam localizados nos hemisférios cerebrais, com números variando de um a três em ovinos infectados. O efeito da presença de cistos no tecido do cérebro foi avaliado. Histopatologicamente, pseudocistos de Toxoplasma gondii foram encontrados em dois animais sem reações inflamatórias detectáveis. Em conclusão, coenurosis e toxoplasmose são graves problemas parasitários que desempenham um papel significativo no manejo de ovelhas no Egito, como resultado do contacto íntimo dos animais com os cães e gatos, que desempenham um papel crítico no ciclo de vida desses parasitas.

OCORRÊNCIA E DISTRIBUIÇÃO ESTACIONAL DE HELMINTOS GASTRINTESTINAIS DE CAPRINOS NO MUNICÍPIO DE TERESINA, PIAUÍ

The objective of this work was to verify the occurence and the seasonal distribution of gastrointestinal helminths of goats during the dry and rainy seasons, for establishing the suitable steps to their control. The trail was carried out at EMBRAPA/UEPAE de Teresina campus, at Teresina There were used male goats from six to eight months old, maintained in a two hectare of Brachiaria humidicola pasture. Five animals stayed in the paddock for the whole period (control) and received no anthelminthic treatment. Monthly, three tracer goats, after receiving three anthelminthic treatments, entered the paddock, there staying exposed to the helminthic infection for 30 days. After that they were put in a cage and replaced by other three tracer goats. After 14 days in the cage they were killed and necropsied for helminths collection, counting and identification. The same procedure was also done to the control goats at the end of the experiment. From January/88 to February/90 there were necropsied 70 tracer goats and five control goats. There were found the following helminths: Haemonchus contortus, Trichostrongylus colubriformis, Strongyloides papillosus, Moniezia expansa, Cooperia punctata. C. curticei, Oesophagostomum columbianum, Trichuris spp (T. ovis, Trichuris sp., T. skrjabini), Skrjabinema ovis, Cysticercus tenuicollis and Paramphistomum spp. There were also identified: Cysticercus tenuicollis and Paramphistomum spp. The necropsy of the tracer goats showed that the helminths transmission occured during the whole year, being highest during the wet season as well as at the beggining of the dry season. The highest intensity helminths in the tracer goats was H. contortus but, in the control goats, was T. colubriformis.

Este trabalho objetiva verificar a ocorrência e distribuição estacional de helmintos gastrintestinais parasitas de caprinos durante as estações seca e chuvosa visando o estabelecimento de medidas adequadas para o controle da verminose. O experimento foi conduzido na base física da EMBRAPA/UEPAE de Teresina, no município de Teresina. Em um piquete de Brachiaria humidicola medindo dois hectares, foram colocados oito caprinos machos, entre seis a oito meses de idade. Cinco animais ficaram permanentes no piquete e não receberam tratamento anti-helmíntico durante todo o período (Testemunhas) e três (incorporados ao trabalho a cada mês), após receberem três tratamentos anti-helmínticos, ficaram expostos à infecção helmíntica durante 30 dias no piquete (traçadores). Mensalmente, após 14 dias de estabulação, eram abatidos e necropsiados três caprinos traçadores e no final do experimento, os testemunhas para coleta, contagem e identificação dos helmintos. De janeiro/88 a fevereiro/90 foram necropsiados 70 caprinos traçadores e cinco testemunhas. Os helmintos identificados foram: Haemonchus contortus, Trichostrongylus colubriformis, Strongyloides papillosus, Moniezia expansa, Cooperia punctata, C. curticei, Oesophagostomum columbianum, Trichuris spp (T. ovis, Trichuris sp., T. skrjabini), Skrjabinema ovis, Cysticercus tenuicollis e Paramphistomum spp. As necropsias nos caprinos traçadores indicaram que ocorreu transmissão de helmintos durante o ano todo sendo em intensidades mais elevadas na época chuvosa e início da época seca e que o helminto de maior intensidade nos caprinos traçadores foi H. contortus, e nos testemunhas T. colubriformis.

Ocorrência e distribuição estacional de helmintos gastrintestinais de caprinos no município de teresina, piauí

The objective of this work was to verify the occurence and the seasonal distribution of gastrointestinal helminths of goats during the dry and rainy seasons, for establishing the suitable steps to their control. The trail was carried out at EMBRAPA/UEPAE de Teresina campus, at Teresina There were used male goats from six to eight months old, maintained in a two hectare of Brachiaria humidicola pasture. Five animals stayed in the paddock for the whole period (control) and received no anthelminthic treatment. Monthly, three tracer goats, after receiving three anthelminthic treatments, entered the paddock, there staying exposed to the helminthic infection for 30 days. After that they were put in a cage and replaced by other three tracer goats. After 14 days in the cage they were killed and necropsied for helminths collection, counting and identification. The same procedure was also done to the control goats at the end of the experiment. From January/88 to February/90 there were necropsied 70 tracer goats and five control goats. There were found the following helminths: Haemonchus contortus, Trichostrongylus colubriformis, Strongyloides papillosus, Moniezia expansa, Cooperia punctata. C. curticei, Oesophagostomum columbianum, Trichuris spp (T. ovis, Trichuris sp., T. skrjabini), Skrjabinema ovis, Cysticercus tenuicollis and Paramphistomum spp. There were also identified: Cysticercus tenuicollis and Paramphistomum spp. The necropsy of the tracer goats showed that the helminths transmission occured during the whole year, being highest during the wet season as well as at the beggining of the dry season. The highest intensity helminths in the tracer goats was H. contortus but, in the control goats, was T. colubriformis.

Este trabalho objetiva verificar a ocorrência e distribuição estacional de helmintos gastrintestinais parasitas de caprinos durante as estações seca e chuvosa visando o estabelecimento de medidas adequadas para o controle da verminose. O experimento foi conduzido na base física da EMBRAPA/UEPAE de Teresina, no município de Teresina. Em um piquete de Brachiaria humidicola medindo dois hectares, foram colocados oito caprinos machos, entre seis a oito meses de idade. Cinco animais ficaram permanentes no piquete e não receberam tratamento anti-helmíntico durante todo o período (Testemunhas) e três (incorporados ao trabalho a cada mês), após receberem três tratamentos anti-helmínticos, ficaram expostos à infecção helmíntica durante 30 dias no piquete (traçadores). Mensalmente, após 14 dias de estabulação, eram abatidos e necropsiados três caprinos traçadores e no final do experimento, os testemunhas para coleta, contagem e identificação dos helmintos. De janeiro/88 a fevereiro/90 foram necropsiados 70 caprinos traçadores e cinco testemunhas. Os helmintos identificados foram: Haemonchus contortus, Trichostrongylus colubriformis, Strongyloides papillosus, Moniezia expansa, Cooperia punctata, C. curticei, Oesophagostomum columbianum, Trichuris spp (T. ovis, Trichuris sp., T. skrjabini), Skrjabinema ovis, Cysticercus tenuicollis e Paramphistomum spp. As necropsias nos caprinos traçadores indicaram que ocorreu transmissão de helmintos durante o ano todo sendo em intensidades mais elevadas na época chuvosa e início da época seca e que o helminto de maior intensidade nos caprinos traçadores foi H. contortus, e nos testemunhas T. colubriformis.