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The aim of this study was to describe the epidemiological, clinical, and pathological findings of two outbreaks of gastrointestinal nematode infections in beef cattle kept under an inadequate sanitary protocol. An outbreak of trichostrongylosis occurred in Amambai, Mato Grosso do Sul (MS), from May to July 2016. The herd consisted of 3,000 Nellore cows, and of these, fifteen died after showing emaciation and diarrhea and remaining in recumbency. At necropsy, the abomasum showed edema in the folds, white, raised areas, multifocal to coalescent, and small ulcers. Histopathology showed larvae compatible with trichostrongylid nematodes were present inside the abomasum glands. Trichostrongylus axei was identify in the abomasum. The hemonchosis outbreak began in October 2018, in a breeding and finishing property in Santa Rita do Pardo, MS. Of 4,000 cattle aged 8 to 18 months, 673 became ill and 117 died. Clinical signs were emaciation, weakness, dehydration, submandibular edema, and soft stools. At necropsy, large numbers of nematodes were found in the abomasum; they were morphologically classified as Haemonchus placei. Both outbreaks were caused by failures in the parasite control protocol. However, in Outbreak I, frost and immune stress caused by lack of food may have contributed to the deaths. In Outbreak I, the main failure in the devermination protocol was the use of anthelmintics without carrying out an efficacy test. In Outbreak II, there was no parasite control protocol in the rearing and finishing property, and in the breeding property, there was resistance to the anthelmintic used (ivermectin). The two outbreaks highlight the importance of gastrointestinal nematode control protocols in cattle and demonstrate that infections by T. axei and H. placei can be lethal for this species.

O objetivo deste trabalho foi descrever os achados epidemiológicos, clínicos e patológicos de dois surtos de verminose em bovinos de corte mantidos sob protocolo sanitário inadequado. Um surto de tricostrongilose ocorreu em Amambai, Mato Grosso do Sul (MS), de maio a julho de 2016. O rebanho de cria era composto por 3.000 vacas Nelore, das quais, quinze vacas adultas morreram após apresentarem emagrecimento, diarreia e permanecerem em decúbito. Na necropsia, o abomaso apresentava edema das pregas, áreas brancacentas, elevadas, multifocais a coalescentes e pequenas úlceras. Na histopatologia, larvas compatíveis com nematódeos tricostrongilídeos estavam presentes no interior das glândulas do abomaso. A recuperação de helmintos do abomaso demonstrou que Trichostrongylus axei foi o principal agente etiológico. O surto de hemoncose iniciou-se em outubro de 2018, em uma propriedade de recria e terminação em Santa Rita do Pardo, MS. Do total de 4 mil bovinos com 8 a 18 meses, 673 adoeceram e 117 morreram. Os sinais clínicos foram emagrecimento, fraqueza, desidratação, edema submandibular e fezes pastosas. Na necropsia, havia grande quantidade de nematódeos no abomaso, que foram classificados morfologicamente como Haemonchus placei. Ambos os surtos foram causados por falhas no protocolo de controle parasitário, porém, no Surto I, geadas e estresse imunológico causado pela falta de alimento podem ter contribuído para as mortes. No Surto I, a principal falha no protocolo de desverminação foi o uso de anti-helmínticos sem a realização de teste de eficácia. No Surto II, não havia protocolo de controle parasitário na propriedade de recria e terminação, e na propriedade de cria, havia resistência ao anti-helmíntico utilizado (ivermectina). Os dois surtos ressaltam a importância dos protocolos de controle de nematódeos gastrintestinais em bovinos e demonstram que infecções por T. axei e H. placei podem ser letais para esta espécie.

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Trichostrongylid em ovelhas foi estudado no Distrito Zhob, Balochistan. Foram coletados 120 tratos gastrointestinais (GIT) de ovelhas do matadouro do distrito. Estas amostras foram processadas para isolamento e identificação de nematódeos tricostrônquicos no Laboratório do Hospital Veterinário do Distrito Zhob. A taxa de prevalência geral foi de 39,1% em machos e 60,8% em fêmeas (p=0,001). A taxa de prevalência em duas raças viz Balochi e Rakhshani foi de 58,3% e 41,6%, respectivamente (p=0,01). A prevalência da espécie observada com Trichostrongylus foi 19,1%, Haemonchus foi 20,8%, Cooperia foi 29,1% e Nematodirus foi 30,8% (p=0,087). Quanto a quantidade de espécies infestadas pelas ovelhas, um único tipo de parasita estava em 32,5% de animais, dois tipos de espécies parasitárias em 36,3% dos animais e três tipos de espécies parasitárias em 30,8% dos animais (p=0,366).(AU)

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Two methodologies were tested to isolate pure Trichostrongylus colubriformis strains from naturally infected sheep. Also, the in vitro susceptibility status to commercial anthelmintic (AH) drugs was determined in these strains. These methods were performed in a tropical region of Mexico where naturally infected sheep and goats host Haemonchus contortus, T. colubriformis and Oesophagostomum columbianum. For the first strain, a group of 6 naturally infected lambs from the "Paraiso" farm were treated with closantel (subcutaneous (SC), 10 mg/kg). On day 10 post-treatment, the eggs per gram (EPG) of faeces were determined with the McMaster technique. The faeces from the two lambs with the highest EPG were used for coprocultures (4 days, 28 °C). The L3 larvae were recovered and identified as T. colubriformis (69%) and O. columbianum (31%). The latter was removed by 10-day refrigeration (4-5 °C) followed by sieving (25 µm), resulting in 100% T. colubriformis (PARAISO strain). The second strain was isolated using repeated doses of levamisole (LEV, SC 7.5 mg/kg) in an 8-year-old sheep. The sheep had 1700 EPG before the LEV treatments and maintained 1300 EPG after both LEV treatments (day 10). The coproculture (4 days, 28 °C) after the second treatment contained 100% T. colubriformis (FMVZ-UADY strain). The in vitro AH susceptibility was determined using the egg hatch test for benzimidazole (BZ), and the larval migration inhibition test for ivermectin (IVM) and LEV. The PARAISO strain was BZ- and LEV-susceptible, and IVM-resistant. Meanwhile, the FMVZ-UADY strain was BZ- and IVM-susceptible, and LEV-resistant. The conditions where these two protocols could be used in other parts of the world were discussed.

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PURPOSE: The aim was to characterize the infection by Trichostrongylus spp. in patients from Chile using a combination of molecular detection techniques and phylogenetic analysis relating the findings to clinical and epidemiological reports of the patients METHODS: Strongylid eggs were detected in seven patients by coproparasitological techniques. From each sample a fragment of the ITS-2 ribosomal gene was amplified by PCR, sequenced and analyzed by the Neighbor-Joining method. RESULTS: All the sequences and phylogenetic clusters corresponded to T. colubriformis. Two samples presented a single nucleotide polymorphism showing two possible haplotypes. Six patients presented gastrointestinal symptoms. All of them lived on farms and used sheep manure as fertilizer. CONCLUSION: T. colubriformis was the strongylid involved in the infections of these Chilean patients associated with the presence of livestock and agricultural practices that favor infection by this type of nematode.

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The objective of this study was to determine the prevalence of gastrointestinal nematode (GIN) infection in goat flocks on semi-arid rangelands of northeastern Mexico (25° N, 350-400 mm annual precipitation). The study included 668 pluriparous goats from 18 herds in five municipalities of Coahuila and Nuevo Leon, Mexico. Five genetic groups were considered (predominance of Boer, Nubian, Alpine, Saanen, and Toggenburg). Fecal samples were taken from the rectum of each animal to determine the number of eggs per gram (EPG) of GIN. The prevalence of flocks with GIN infections was 88.9%. Similar results were observed for the number of goats infected in the flocks. The Alpine breed presented the highest prevalence and highest EPG loads of GIN, whereas Boer and Nubian were the genetic groups with the lowest (P < 0.05) EPG. There was a negative effect of GIN infection on the live weight of goats (P < 0.05). The GIN genera found were Trichostrongylus spp. and Haemonchus spp. It was concluded that in the goat flocks of the semi-arid zones of Mexico was found a high prevalence of infections with gastrointestinal nematodes. The municipality and the breed of the animals were factors that showed influence on this prevalence and the level of infection of the goats.

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The survival of infective larvae (L3) of Trichostrongylus colubriformis was evaluated on Brachiaria, Coast-cross and Aruana forage grasses. Feces of sheep parasitized exclusively by T. colubriformis were deposited in winter and spring on experimental plots whose grasses were cut at two heights: 5 cm and 30 cm. One, two, four, eight, 12 and 16 weeks after depositing the feces, fecal and forage samples were collected for the retrieval and quantification of L3. Retrieval of L3 from feces and forage was negligible in winter due to the dry weather, although a few larvae were retrieved in the last larval collections. However, L3 retrieval from fecal samples was greater in spring, especially two weeks after feces were deposited on 30 cm high grasses. At this time, the L3 retrieval rate from the three forage grasses differed significantly (P <0.05), with Aruana grass showing the highest average L3 retrieval rate, followed by Coast-cross and Brachiaria. In conclusion, the winter drought proved very unfavorable for the presence of L3 in the environment, and the microclimate of Aruana pastureland was generally the most favorable for the retrieval of infective larvae.

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Foram avaliados os aspectos epidemiológicos e a dinâmica das infecções por helmintos gastrintestinais em bovinos da Mesorregião do Sudoeste Paranaense. Amostras de fezes de 473 bovinos criados em sistema extensivo foram coletadas para a contagem de ovos de nematódeos por grama de fezes (OPG). Coproculturas foram realizadas com as amostras que continham ovos para obtenção e identificação de larvas infectantes. Os resultados foram analisados pelos testes de Qui-quadrado ou Exato de Fischer. Detectou-se a prevalência dos gêneros Haemonchus, Cooperia, Trichostrongylus, Ostertagia e Oesophagostomum. As novilhas foram mais susceptíveis às infecções por nematodeos gastrintestinais em comparação com as vacas, sendo Haemonchus, Cooperia e Ostertagia os gêneros de parasitas mais prevalentes nestes animais.

Epidemiological aspects and dynamics of gastrointestinal helminthes were evaluated in cattle from Parana Southwest Region. Stool samples from 473 animals raised in extensive system were collected and analyzed for nematode eggs per gram faeces (EPG). Faecal cultures were made with samples that contained eggs in order to identify third stage larvae. The results were analyzed by Chi-square or Fischer exact tests. The following genera were found: Haemonchus, Cooperia, Trichostrongylus, Ostertagia and Oesophagostomum. The heifers were more susceptible to nematode gastrointestinal infections than the adult animals and Haemonchus, Cooperia and Ostertagia were the most common genera found in those animals.

Fueron evaluados los aspectos epidemiológicos y la dinamica de las infecciones por helmintos gastrointestinales de bovinos de la Mesoregión del Sudoeste Paranaense. Se tomaron muestras de heces de 473 bovinos criados bajo sistema extensivo para recuentos de huevos de nemátodos por gramo de heces (HPG). Se hicieron coprocultivos con las muestras que tenían huevos para obtención de larvas y su identificación. Los datos fueron analizados por medio del test Chi cuadrado o exacto de Fisher. Se detectó una prevalencia de los géneros Haemonchus, Cooperia, Trichostrongylus, Ostertagia y Oesophagostomum. La media de conteo de huevos según categoría de hembras fué mayor para las novillas que en vacas. Haemonchus, Cooperia y Ostertagia son los géneros de parasitos más prevalentes en estos animales.

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This experiment aimed to assess the recovery of infective larvae (L3) of Trichostrongylus colubriformis from Brachiaria decumbens cv. Australiana, Cynodon dactylon cv. Coast-cross and Panicum maximum cv. Aruana. The experimental module comprised six plots, with two plots per herbage species. Larval survival was assessed from autumn to winter, under the effect of two herbage-paring heights (5 and 30 cm). TThe paring was carried out immediately before contamination with faces containing T. colubriformis eggs. The feces and herbage were collected at one, two, four, eight, 12 and 16 weeks after feces had been deposited in the experimental plots. In general, larvae were recovered from both herbage and feces until the 16th week. The longer persistence of these larvae in the environment was probably due to warmer temperatures. The number of L3 recovered from the pasture was not influenced by the height of plants, except for Brachiaria and Aruana herbage in the fourth week. Regarding the concentrations of larvae per kg of dry matter (L3/kg DM), recovery was higher from low pasture in all three herbage species. During the autumn, the development and survival of the T. colubriformis free-living stages were not affected by the different herbage species.

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Biological control is an alternative method to reduce the population of parasites through natural predators. A promising option of biological control in the reduction of infective larvae on pasture is the use of nematophagous fungi. In this study, the efficacy of the nematophagous fungus Duddingtonia flagrans in controlling gastrointestinal nematode parasites in field-raised horses was tested. Ten foals with an average age of 12 months were divided in two groups: five males constituted the treated group and five females constituted the control group. Each group was introduced in a field of mixed pasture with approximately 5 ha. The treated group received the fungus D. flagrans at a concentration of 10(6) chlamydospores per kilogramme of animal body weight daily, mixed with horse food for 5 months. The control group did not receive the fungus. Samples were collected to perform eggs per gramme (EPG) counts weekly. Coproculture and collection of pasture were done monthly for larvae counting. No significant difference was observed in the EPG counting and in the number of larvae recovered from coprocultures, where cyathostomines, Strongylus and Trichostrongylus spp. were found after monthly larvae counting. No significant difference was observed in the EPG counts, and Trichostrongylus sp. was identified. The number of recovered larvae on pasture was significantly lower in the treated group in the last month of treatment, showing a reduction of 73.5% (p < 0.05). As such, the fungus was able to reduce the number of infective larvae in the pasture. Nevertheless, this did not reflect in a decrease of parasitic infection during the 5-month study period.

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O experimento teve como objetivo avaliar a recuperação de larvas infectantes (L3) de Trichostrongylus colubriformis em Brachiaria decumbens cv. Australiana, Cynodon dactilon cv. Coast-cross e Panicum maximum cv. Aruana. Foram utilizados módulos experimentais constituídos por seis canteiros de 32,4 m² cada, perfazendo dois canteiros por espécie forrageira. Cada canteiro foi dividido em 36 parcelas, de 30 x 30 cm, de forma a permitir seis repetições por espécie e por altura da forragem em cada semana de colheita de material. A sobrevivência larval foi avaliada do meio do verão e até meados do outono, sob o efeito de duas alturas de poda das forragens: baixa, 5 cm e alta, 30 cm. A poda foi realizada imediatamente antes da deposição das fezes contaminadas com ovos de T. colubriformis, obtidos de ovinos, que ocorreu no dia 05/02/ 2004. A colheita das fezes e da forragem foi realizada uma, duas, quatro, oito, 12 e 16 semanas após a deposição das fezes nos canteiros experimentais. A altura da forragem foi medida em cada uma das subdivisões imediatamente antes da colheita. A forragem foi cortada rente ao solo, de uma área delimitada com o auxílio de um círculo de 10 cm de raio. As fezes foram recolhidas manualmente dos canteiros. O número de larvas infectantes recuperado foi muito pequeno em comparação com a quantidade de larvas produzidas nas culturas controle, mantidas no laboratório (máximo de 6,7 por cento no capim Aruana com 30 cm de altura). Arecuperação de L3 das amostras fecais foi maior quando as fezes foram depositadas em meio ao capim alto (com 30 cm - P<0,05). Porém, a recuperação de L3 das forragens foi similar em ambos os cortes. Em relação à concentração de L3 (número de L3/kg de matéria seca), não houve diferença entre o corte baixo e alto (P>0,05) em nenhuma das semanas experimentais. Dentre as espécies forrageiras, o capim aruana foi o que, no geral, apresentou maiores concentrações de L3 de T. colubriformis.

The purpose of the experiment was to evaluate infective Trichostrongylus colubriformis larvae (L3) survival in three forage species. Experimental plots, planted with Brachiaria decumbens cv. Australian, Cynodon dactilon cv. Coast-cross, and Panicum maximum cv. Aruana, were used in the study, totaling two plots for each species. Each plot (32.4 m²) was divided into 36 subplots (30 x 30 cm) in order to allow six replicates per forage species and per herbage height in each week of material collection. Larval recovery was evaluated from middle summer to middle autumn under the effect of two forage paring heights: low, 5 cm, and high, 30 cm. The paring was carried out immediately before the fecal samples with T. colubriformis eggs, taken from sheep, were deposited on pasture in 05/Feb/2004. Feces and forage collection was performed one, two, four, eight, 12 and 16 weeks after feces deposition in the experimental plots. Forage grass height was measured in each subdivision immediately before the collections. The forage sample was cut, close to the soil, from an area delimited with a circle with a 10-cm radius. The feces were collected from the subplots. The number of infective larvae recovered from pasture was very small in compa6rison with the amount of larvae produced in cultures maintained in laboratory (maximum 6.7 percent on Aruana grass with 30 cm). L3 recovery rates from fecal samples were bigger when the feces were deposited on high grass (measuring 30 cm - P<0.05). L3 recovery from pasture and L3 concentration on herbage (L3/Kg dry matter) were similar for both cuts (P> 0.05). Among the forage species, the Aruana grass was the one that, in general, harbored the biggest concentrations of infective T. colubriformis larvae.

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The purpose of the experiment was to evaluate infective Trichostrongylus colubriformis larvae (L3) survival in three forage species. Experimental plots, planted with Brachiaria decumbens cv. Australian, Cynodon dactilon cv. Coast-cross, and Panicum maximum cv. Aruana, were used in the study, totaling two plots for each species. Each plot (32.4 m(2)) was divided into 36 subplots (30 x 30 cm) in order to allow six replicates per forage species and per herbage height in each week of material collection. Larval recovery was evaluated from middle summer to middle autumn under the effect of two forage paring heights: low, 5 cm, and high, 30 cm. The paring was carried out immediately before the fecal samples with T. colubriformis eggs, taken from sheep, were deposited on pasture in 05/Feb/2004. Feces and forage collection was performed one, two, four, eight, 12 and 16 weeks after feces deposition in the experimental plots. Forage grass height was measured in each subdivision immediately before the collections. The forage sample was cut, close to the soil, from an area delimited with a circle with a 10 cm radius. The feces were collected from the subplots. The number of infective larvae recovered from pasture was very small in comparison with the amount of larvae produced in cultures maintained in laboratory (maximum 6.7% on Aruana grass with 30 cm). L3 recovery rates from fecal samples were bigger when the feces were deposited on high grass (measuring 30 cm - P<0.05). L3 recovery from pasture and L3 concentration on herbage (L3/Kg dry matter) were similar for both cuts (P>0.05). Among the forage species, the Aruana grass was the one that, in general, harbored the biggest concentrations of infective T. colubriformis larvae.

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The purpose of the experiment was to evaluate infective Trichostrongylus colubriformis larvae vertical migration in two forage grass species. Experimental modules formed by eight plots, established with Brachiaria decumbens cv. Australian and Panicum maximum cv. Aruana, were used in the study, totaling four plots for each grass species. Each plot was divided into six 30 x 30 cm subplots. Larval migration was evaluated in the four seasons of the year, in different plant strata (0-7, 7-14, 14-21, 21-28 and above 28 cm). Four feces deposits were made, one in each season of the year, in the middle of 30-cm tall forage. The feces were collected from the forage ten days after each feces deposit in the experimental subplots. Grass height was measured in each of the strata immediately before the collections. The forage of the different strata was cut from an area measuring 10-cm in radius. The feces were collected manually from the subplots. There was a grass species and grass stratum interaction in the deposit made in autumn (P<0.05). During that season, most of the larvae were recovered from the Brachiaria grass base; meanwhile, at the forage apex, the biggest average was registered in the aruana grass. Infective larvae (L3) recovery was similar among the different strata during spring. In springtime, the biggest L3 recovery occurred at the 21-28 cm stratum from both forage species. No L3 was recovered from any of the No L3 was recovered from any of the grass strata during winter and summer. Study results show that migration of T. colubriformis larvae was more influenced by weather conditions than by forage species.

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The study was carried out to evaluate the relationship of inflammatory intestinal cells with the resistance to Trichostrongylus colubriformis infections in three breeds of sheep (Santa Ines, Suffolk and Ile de France), naturally infected. Mast cells, eosinophils, and globule leucocytes were enumerated in intestinal mucosa. Histamine concentration was estimated in intestinal tissue samples and the length of male and female specimens were determined. The three breeds of sheep showed similar cellular response in the small intestine mucosa (P>0.05). There was extensive variation among sheep in the parasitological and inflammatory cell variables, even in lambs of the same breed. In general, animals presenting less inflammatory cells had a larger worm burden, higher fecal egg counts, and larger T. colubriformis worms. The inflammatory cells possibly impaired the parasite's establishment, development, and survival.

Avaliaram-se a associação entre o número de células inflamatórias no intestino delgado e a resistência à infecção por Trichostrongylus colubriformis em ovinos de três raças (Santa Inês, Suffolk e Ile de France), naturalmente infectados. Mastócitos, eosinófilos e leucócitos globulares foram quantificados na mucosa intestinal. A concentração de histamina foi estimada em amostras teciduais do intestino, bem como foi determinado o comprimento de machos e fêmeas de T. colubriformis. A resposta celular foi similar na mucosa intestinal das três raças ovinas (P>0,05). Houve grande variação entre os ovinos em relação aos resultados parasitológicos e celulares, mesmo nos animais de mesma raça. Em geral, os animais que apresentaram número menor de células inflamatórias tiveram cargas parasitárias maiores, contagens de ovos por grama de fezes mais altas e exemplares de T. colubriformis maiores. Os resultados indicaram que mastócitos, eosinófilos e leucócitos globulares prejudicaram o estabelecimento, o desenvolvimento e a sobrevivência dos parasitas.

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The study was carried out to evaluate the relationship of inflammatory intestinal cells with the resistance to Trichostrongylus colubriformis infections in three breeds of sheep (Santa Ines, Suffolk and Ile de France), naturally infected. Mast cells, eosinophils, and globule leucocytes were enumerated in intestinal mucosa. Histamine concentration was estimated in intestinal tissue samples and the length of male and female specimens were determined. The three breeds of sheep showed similar cellular response in the small intestine mucosa (P>0.05). There was extensive variation among sheep in the parasitological and inflammatory cell variables, even in lambs of the same breed. In general, animals presenting less inflammatory cells had a larger worm burden, higher fecal egg counts, and larger T. colubriformis worms. The inflammatory cells possibly impaired the parasite's establishment, development, and survival.(AU)

Avaliaram-se a associação entre o número de células inflamatórias no intestino delgado e a resistência à infecção por Trichostrongylus colubriformis em ovinos de três raças (Santa Inês, Suffolk e Ile de France), naturalmente infectados. Mastócitos, eosinófilos e leucócitos globulares foram quantificados na mucosa intestinal. A concentração de histamina foi estimada em amostras teciduais do intestino, bem como foi determinado o comprimento de machos e fêmeas de T. colubriformis. A resposta celular foi similar na mucosa intestinal das três raças ovinas (P>0,05). Houve grande variação entre os ovinos em relação aos resultados parasitológicos e celulares, mesmo nos animais de mesma raça. Em geral, os animais que apresentaram número menor de células inflamatórias tiveram cargas parasitárias maiores, contagens de ovos por grama de fezes mais altas e exemplares de T. colubriformis maiores. Os resultados indicaram que mastócitos, eosinófilos e leucócitos globulares prejudicaram o estabelecimento, o desenvolvimento e a sobrevivência dos parasitas.(AU)

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O problema da resistência em nematódeos gastrintestinais de caprinos, associado ao crescente interesse por alternativas de controle, levou à investigação da ação de Azadirachta indica sobre estes parasitas. No teste in vitro observou-se a ação ovicida e larvicida de extratos aquosos de folhas verdes e secas de Neem, em cinco concentrações. No teste in vivo administrou-se 30g de folhas secas por animal/dia, durante cinco dias. Os animais foram monitorados através de OPG diário durante 28 dias e as larvas foram quantificadas e identificadas através de coprocultura. Detectou-se a predominância de Haemonchus sp. na estação chuvosa e de Trichostrongylus spp. na estação seca. O extrato aquoso de folhas secas in vitro, na concentração de 240.000ppm, reduziu em 89% a eclosão das larvas de nematódeos gastrintestinais. Entretanto, esta concentração é muita elevada e inviabiliza sua aplicação no controle da verminose. A administração oral de folhas secas trituradas não reduziu o OPG dos animais durante um período de 28 dias após o tratamento. Estudos investigativos com A. indica devem se concentrar na ação biológica do óleo extraído diretamente da semente, que possui maior quantidade de azadirachtina que as folhas. A administração do óleo também é mais fácil, já que as folhas têm sabor amargo e são evitadas pelos animais.

The resistance problem in goats gastrointestinal nematodes, associated to the increasing interest for control alternatives, induced the investigation of the Azadirachta indica action on these parasites. In in vitro test it was detected ovicida and larvicida action of Neem dry and fresh leaves aqueous extracts in five concentrations. In in vivo test each animal received orally 30g of dry leaves for a five days period. To monitor the animals were used diary fecal eggs per gram count (FEC) by 28 days and larvae were quantified and identified through fecal culture. Predominance of Haemonchus sp. in rainy season and Trichostrongylus spp. in dry season were detected. The dry leaves aqueous extract reduced in 89% the larvae hatching of goats’ gastrointestinal nematodes, in 240.000ppm concentration. However this is a very high concentration to be applied on vermin’s control. The oral administration of Azadirachta indica triturated dry leaves did not reduce the medicated animals FEC during a period of 28 days after treatment. A. indica investigated studies must be concentrated in biological action of the seed oil extracted, because it possess bigger amount of azadirachtina than leaves. The oil administration also is easier, whereas the leaves have bitter taste and are prevented by animals.

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O problema da resistência em nematódeos gastrintestinais de caprinos, associado ao crescente interesse por alternativas de controle, levou à investigação da ação de Azadirachta indica sobre estes parasitas. No teste in vitro observou-se a ação ovicida e larvicida de extratos aquosos de folhas verdes e secas de Neem, em cinco concentrações. No teste in vivo administrou-se 30g de folhas secas por animal/dia, durante cinco dias. Os animais foram monitorados através de OPG diário durante 28 dias e as larvas foram quantificadas e identificadas através de coprocultura. Detectou-se a predominância de Haemonchus sp. na estação chuvosa e de Trichostrongylus spp. na estação seca. O extrato aquoso de folhas secas in vitro, na concentração de 240.000ppm, reduziu em 89% a eclosão das larvas de nematódeos gastrintestinais. Entretanto, esta concentração é muita elevada e inviabiliza sua aplicação no controle da verminose. A administração oral de folhas secas trituradas não reduziu o OPG dos animais durante um período de 28 dias após o tratamento. Estudos investigativos com A. indica devem se concentrar na ação biológica do óleo extraído diretamente da semente, que possui maior quantidade de azadirachtina que as folhas. A administração do óleo também é mais fácil, já que as folhas têm sabor amargo e são evitadas pelos animais.(AU)

The resistance problem in goats gastrointestinal nematodes, associated to the increasing interest for control alternatives, induced the investigation of the Azadirachta indica action on these parasites. In in vitro test it was detected ovicida and larvicida action of Neem dry and fresh leaves aqueous extracts in five concentrations. In in vivo test each animal received orally 30g of dry leaves for a five days period. To monitor the animals were used diary fecal eggs per gram count (FEC) by 28 days and larvae were quantified and identified through fecal culture. Predominance of Haemonchus sp. in rainy season and Trichostrongylus spp. in dry season were detected. The dry leaves aqueous extract reduced in 89% the larvae hatching of goats gastrointestinal nematodes, in 240.000ppm concentration. However this is a very high concentration to be applied on vermins control. The oral administration of Azadirachta indica triturated dry leaves did not reduce the medicated animals FEC during a period of 28 days after treatment. A. indica investigated studies must be concentrated in biological action of the seed oil extracted, because it possess bigger amount of azadirachtina than leaves. The oil administration also is easier, whereas the leaves have bitter taste and are prevented by animals.(AU)

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Se analizaron los parásitos de 40 liebres (Lepus europeaus) (20 de la Provincia de Ñuble y 20 de Última Esperanza) capturadas entre enero de 2003 y agosto de 2004. En la Provincia de Ñuble se aislaron tres especies de endoparásitos: Trichostrongylus retortaeformis (60 por ciento), Passa-lurus ambiguus (5 por ciento) y Eimeria spp. (45 por ciento). En Última Esperanza se encontró sólo la especie T. retortaeformis (60 por ciento). Se aisló además una especie de ectoparásito correspondiente al Phthiraptera Haemodipsus lyriocephalus en una liebre de la Provincia de Ñuble. No se estableció ninguna relación significativa entre la presencia de los parásitos gastrointestinales con el sexo y edad de las liebres. Tampoco hubo una diferencia significativa entre el parasitismo provocado por T. retortaeformis en las dos zonas estudiadas.

The parasites of 40 Lepus europaeus (hares) were analyzed (20 of the Ñuble Province and 20 of Ultima Esperanza) caught between January 2003 and August 2004. In the Ñuble province three endoparasites species were isolated: Trichostrongylus retortaeformis (60%), Passalurus ambiguus (5%) and Eimeria spp. (45%). In Ultima Esperanza only T. retortaeformis was isolated with 60% of infection. The ectoparasite species isolated corresponded to the Phthiraptera Haemodipsus lyriocephalus in a hare of the Ñuble Province. No significant differences in the presence of gastrointestinal parasites were found with respect to sex and age of the hare. Nor was there any significant difference between parasitism of T. retortaeformis in the two studied zones.

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Bezerros traçadores foram utilizados para avaliar a contaminação sazonal das pastagens por helmintos gastrintestinais e pulmonares em uma propriedade de exploração leiteira na região Campo das Vertentes,Minas Gerais. Os animais se infectaram durante todos os meses do ano. As maiores cargas parasitárias.foram recuperadas no período chuvoso (setembro - abril), e o pico foi observado em abril-maio, final do período chuvoso. As espécies recuperadas foram Cooperia punctata, C. spatulata, Haemonchus contortus, H. similis, Oesophagostomum radiatum, Trichostrongylus axei, T. colubriformis, Trichuris discolor, T. globulosa, Dictyocaulus viviparus e Agriostomum vryburgi. Para avaliar a dinâmica das infecções, foi acompanhado um grupo de vacas com seus bezerros lactantes no período de janeiro de 1999 a fevereiro de 2000. Os valores da contagem de ovos por grama de fezes (OPG) dos bezerros apresentaram dois picos, em maio de 1999 e fevereiro de 2000, enquanto o pico da contagem de OPG das vacas ocorreu em julho e agosto de 2000. Nas coproculturas, os gêneros de maior ocorrência foram Cooperia e Haemonchus nos bezerros, e Haemonchus e Trichostrongylus nas vacas.

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Bezerros traçadores foram utilizados para avaliar a contaminação sazonal das pastagens por helmintos gastrintestinais e pulmonares em uma propriedade de exploração leiteira na região Campo das Vertentes, Minas Gerais. Os animais se infectaram durante todos os meses do ano. As maiores cargas parasitárias foram recuperadas no período chuvoso (setembro - abril), e o pico foi observado em abril-maio, final do período chuvoso. As espécies recuperadas foram Cooperia punctata, C. spatulata, Haemonchus contortus, H. similis, Oesophagostomum radiatum, Trichostrongylus axei, T. colubriformis, Trichuris discolor, T. globulosa, Dictyocaulus viviparus e Agriostomum vryburgi. Para avaliar a dinâmica das infecções, foi acompanhado um grupo de vacas com seus bezerros lactantes no período de janeiro de 1999 a fevereiro de 2000. Os valores da contagem de ovos por grama de fezes (OPG) dos bezerros apresentaram dois picos, em maio de 1999 e fevereiro de 2000, enquanto o pico da contagem de OPG das vacas ocorreu em julho e agosto de 2000. Nas coproculturas, os gêneros de maior ocorrência foram Cooperia e Haemonchus nos bezerros, e Haemonchus e Trichostrongylus nas vacas.(AU)

Tracer calves used to monitor contamination of pasture with pulmonary and gastrointestinal nematode helminths on a dairy farm were infected throughout the year. The highest parasite burdens were observed during the rainy season (September April). However, the highest peak occurred in April and May 1999, the end of the rainy season. Helminth species recovered from the calves were Cooperia punctata, C. spatulata, Haemonchus contortus, H. similis, Oesophagostomum radiatum, Trichostrongylus axei, T. colubriformis, Trichuris discolor, T. globulosa, Dictyocaulus viviparus and Agriostomum vryburgi. A group of lactating cows and their accompanying calves were followed during the period from January 1999 to February 2000 to evaluate the dynamics of their infection. Parasite eggs per gram of feces (EPG) exhibited two peaks in the calves, May 1999 and February 2000; while EPG peaks in cows occurred in July and August 2000. Cooperia and Haemonchus were the most prevalent genera in fecal cultures from calves, whereas in cow fecal cultures, the highest prevalence was for Haemonchus and Trichostrongylus.(AU)

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Eleven male two-month-old Holstein calves were used to determine the pathological changes induced by a Cooperia punctata infection. After weaning, ten calves received a single oral dose of 45,000 C. punctata infective larvae. One calf remained as a non-infected control. Groups of two calves were killed on days 7, 14, 21, 28 and 35 post-infection (p.i.) for determination of worm burdens and histopathological evaluation. The small intestine was sub-divided into three sections of approximately equal length, and representative samples of mucosa were fixed in 10% formalin, cut, and stained with haematoxylin-eosin. Samples of intestinal contents and mucosal digests were taken and fixed in 10% formalin for an estimation of total worm burdens. An increase in the number of adult parasites and a decrease in the number of larvae were observed with time (P<0.001). A higher concentration of worms was found in the first segment of the small intestine during the five weeks of observation. Histology showed larvae in the intestinal mucosa on day 7 p.i., with a discrete increase in the cellular response. Adult worms and a marked cellular infiltrate with eosinophils and neutrophils were present on day 21 p.i., and these persisted until day 35 p.i. Microcysts resulting from worm destruction were observed from day 21 p.i.

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