RESUMO
Understanding gastrointestinal parasite distribution is crucial for effective control programs in horses. This study reports the prevalence of helminth infections in horses and selected risk factors (i.e., breed, age, climate, season) by analyzing 19,276 fecal samples from the Laboratory of Veterinary Clinical Parasitology, in Curitiba, Southern Brazil. The analyses were carried out from 2008 to 2019, coming from 153 stud farms located in 60 municipalities of nine Brazilian states. The parasite prevalence was 73.3%, with 72.1% present in the adult population and 80.6% in young horses. Strongyles were present in 100% horse farms. Strongyles had a prevalence of 72.1% with a mean FEC of 453.53 (+/- 717.6). Parascaris spp. had a prevalence of 5.8% and a FEC of 17.11 (+/- 149.2). The tropical wet/monsoon climate (Am) showed the lowest FEC for strongyles and Parascaris spp. when compared to the other climates. In the logistic regression analysis, young horses exhibited 4.6 times higher odds ratio (OR) (3.9-5.5) of Parascaris spp. and 1.2 (1.1-1.4) times higher OR of strongyles egg shedding when compared to adults (P < 0.001). Summer presented a higher risk for Parascaris spp. and Strongyles eggs when compared to the other seasons (P < 0.001). Mangalarga Marchador, Criollo, and Crossbred breeds were identified with higher OR of Parascaris spp. egg shedding than Thoroughbred. The extensive prevalence of strongyles across ages, seasons, breeds, and climates alerts for the risk of clinical manifestations in equines raised on pastures designing optimal health management and parasite control strategies worldwide.
Assuntos
Gastroenteropatias , Helmintíase Animal , Doenças dos Cavalos , Fatores Etários , Brasil/epidemiologia , Clima , Coinfecção/epidemiologia , Coinfecção/parasitologia , Coinfecção/veterinária , Fezes/parasitologia , Gastroenteropatias/diagnóstico , Gastroenteropatias/epidemiologia , Gastroenteropatias/parasitologia , Gastroenteropatias/veterinária , Helmintíase Animal/diagnóstico , Helmintíase Animal/epidemiologia , Doenças dos Cavalos/diagnóstico , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/parasitologia , Contagem de Ovos de Parasitas/veterinária , Prevalência , Estudos Retrospectivos , Fatores de Risco , Estações do Ano , AnimaisRESUMO
Haemonchus contortus and Trichostrongylus colubriformis are the most important gastrointestinal nematodes causing serious losses in sheep production of tropical and subtropical regions. Prophylaxis of gastrointestinal nematode infections is based on anthelmintics use, but their frequent administration selects multiple-resistant parasites. To evaluate how the situation has changed over the last decades, the anthelmintic resistance status of gastrointestinal nematodes in sheep flocks was assessed in the current study and compared to previous surveys. In each one of the 15 flocks evaluated, animals (n ≥ 7) were allocated into at least five groups and treated as follows: 1) untreated control; 2) albendazole; 3) levamisole; 4) ivermectin; and 5) monepantel. If more animals were available, two additional groups were included: 6) closantel, and 7) moxidectin. The faecal egg count reduction test (FECRT) was carried out to evaluate the pre- and post-treatment using the SHINY tool. Haemonchus spp. was the most prevalent nematode from faecal cultures. The mean efficacy of albendazole was 40%. Only in two farms, levamisole presented a relatively high percentage of reduction in the FECRT about 90%, while ivermectin and moxidectin presented the worst mean efficacy of 34% and 21% among all farms, respectively. Like other anthelmintics, closantel demonstrated low efficacy (63%) across all farms evaluated. Monepantel presented an overall mean efficacy of 79%, but it was the only anthelmintic that presented efficacy ≥95%, in five farms. The results revealed that gastrointestinal nematodes with multiple anthelmintic resistance were prevalent in all 15 sheep herds. The research suggests that nematodes are becoming more and more resistant to various anthelmintic compounds, which has made the problem worse. This circumstance highlights the necessity to put into practice sustainable and long-lasting methods to prevent gastrointestinal nematode infections in sheep husbandry.
Assuntos
Aminoacetonitrila/análogos & derivados , Anti-Helmínticos , Haemonchus , Macrolídeos , Nematoides , Infecções por Nematoides , Salicilanilidas , Doenças dos Ovinos , Animais , Ovinos , Levamisol/farmacologia , Levamisol/uso terapêutico , Ivermectina/uso terapêutico , Albendazol/uso terapêutico , Brasil/epidemiologia , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/veterinária , Fezes/parasitologia , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/parasitologia , Contagem de Ovos de Parasitas/veterinária , Resistência a MedicamentosRESUMO
Fascioliasis is a trematodiasis that affects domestic and wild animals as well as humans worldwide. It is a well-recognized disease in livestock, were it produces serious economic losses. Yet in cattle, there is limited information about the burden of liver flukes and its relation to the eggs per gram shed to the environment. There is also lack of knowledge on the effect of parasite load in blood parameters of infected animals, which is important to evaluate the severity and progression of the disease. The objective of this work was to gain insight in these aspects. Cattle from Mendoza province, Argentina, were inspected at a farm and at the abattoir determining the presence or absence of Fasciola hepatica. Each animal was sampled for blood and feces and in the slaughterhouse the livers were inspected. Hematology and blood chemistry parameters were determined, feces were examined for F. hepatica eggs by a quantitative sedimentation technique and livers were thoroughly inspected to determine the number of flukes. Infected cattle presented a mild burden of liver flukes per animal, strongly correlated (r = 0.72) to the number of eggs per gram of feces. The total number of eggs (XÌ=35,100) shed per animal to the environment and the type of livestock management techniques in the region exacerbate the role of cattle as efficient reservoirs of this disease. Statistically significant lower red blood cell, lymphocyte and neutrophil counts were observed in infected compared to uninfected animals. All hepatic parameters tested showed highly statistically significant differences (p < 0.001) as well as proteins by cause of rise of globulins in infected cattle. The correlation between the amount of flukes in the liver and the number of eggs per gram of faces indicates coprology as a reliable and cost-effective method to infer parasite burden. The impact of fascioliasis on blood parameters can be of aid for the veterinary practitioner on the assessment of this disease on cattle.
Assuntos
Doenças dos Bovinos , Fasciola hepatica , Fasciolíase , Fezes , Carga Parasitária , Animais , Fasciolíase/veterinária , Fasciolíase/sangue , Fasciolíase/parasitologia , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/sangue , Doenças dos Bovinos/epidemiologia , Fezes/parasitologia , Fasciola hepatica/isolamento & purificação , Argentina/epidemiologia , Contagem de Ovos de Parasitas , Fígado/parasitologia , Análise Química do Sangue , Doença Crônica , MatadourosRESUMO
In the fall of 2022, decreased triclabendazole (TCBZ) efficacy against F. hepatica was suspected in a sheep farm located in the Santa Cruz province, Argentinian Patagonia. Since TCBZ-resistance in F. hepatica has never been reported in this province, this study aimed to confirm potential TCBZ-resistance in F. hepatica and to evaluate the efficacy of closantel (CLO) and nitroxinil (NTX), through faecal egg count reduction test (FECRT), and the efficacy of albendazole (ABZ) through the in vitro egg hatch test (EHT) in sheep. Sixty-eight (68) animals were selected from a herd of eighty (80) female Merino naturally infected with F. hepatica based on eggs per gram of F. hepatica (EPGFh) counts and assigned into four (4) groups (n = 17 per group): Group Control, animals did not receive anthelmintic treatment; Group TCBZ, animals were orally treated with TCBZ (12 mg/kg); Group CLO, animals were orally treated with CLO (10 mg/kg); and Group NTX, animals were subcutaneously treated with NTX (10 mg/kg). The fluke egg output was monitored on days 0 and 21 post-treatment. For the EHT, liver fluke eggs were isolated from faecal samples (approx. 50 g) collected from animals of the control group. TCBZ efficacy against liver fluke was 53.4%, confirming the presence of TCBZ-resistant isolates on the farm. CLO and NTX were highly effective (100%) for the treatment of F. hepatica on this farm. The EHT was carried out in two different laboratories, in which was observed an ABZ efficacy of 95.8 (Bariloche) and 96.5% (Tandil). These results indicate the ABZ susceptibility of this F. hepatica isolate and the inter-laboratory precision of the test.
Assuntos
Fasciola hepatica , Fasciolíase , Doenças dos Ovinos , Feminino , Ovinos , Animais , Triclabendazol/uso terapêutico , Fasciolíase/tratamento farmacológico , Fasciolíase/veterinária , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Resistência a Medicamentos , Doenças dos Ovinos/tratamento farmacológico , Albendazol/farmacologia , Albendazol/uso terapêutico , Nitroxinila , Carneiro DomésticoRESUMO
Anthelmintic efficacy was evaluated among sheep that had become naturally infected with gastrointestinal nematodes in 17 flocks located in the semiarid region of Minas Gerais, Brazil. Feces were collected individually from 1021 hairy sheep to determine the number of eggs per gram of feces (EPG) and for coprocultures to identify nematode genera the nematodes. Only the animals that presented EPG counts greater than or equal to 200 were included in the study (totaling 381 sheep). The animals were divided into three treatment groups: albendazole, ivermectin and levamisole. Fourteen days after the administration of anthelmintics, fecal samples were taken from all animals. In each flock, the pre-treatment and post-treatment arithmetic mean EPG were used to calculate the efficacy (FECR) for each of the treatment groups and the lower 95% confidence limit. Data were analyzed with the "eggCounts 2.3" package in RStudio, using a Bayesian model for paired design. The anthelmintics were classified as being efficacious (when the FECR was both equal to or above 95% and the lower 95% confidence limit was equal to or above 90%) or as encountering anthelmintic resistance (when the FECR was below 95% and the lower 95% confidence limit was below 90%) or inconclusive (when none of the other criteria were fulfilled). Albendazole and ivermectin were not effective in any of the flocks. Levamisole was effective against gastrointestinal nematodes in 25% of the flocks studied. Haemonchus, Trichostrongylus and Oesophagostomum genera were identified in this study in a semiarid region of Minas Gerais, Brazil. The genus Haemonchus was the most prevalent, followed by Trichostrongylus and Oesophagostomum. After anthelmintic treatment, the most prevalent genus was Haemonchus, followed by Trichostrongylus; the genus Oesophagostomum was not detected. The highest percentage of Haemonchus larvae was observed after treatment with ivermectin, followed by albendazole and levamisole. This study revealed the existence of gastrointestinal nematodes in sheep that present multiple resistance to all three main classes of anthelmintic drugs.
Assuntos
Anti-Helmínticos , Haemonchus , Nematoides , Animais , Ovinos , Levamisol/farmacologia , Levamisol/uso terapêutico , Albendazol/farmacologia , Albendazol/uso terapêutico , Ivermectina/farmacologia , Ivermectina/uso terapêutico , Brasil/epidemiologia , Teorema de Bayes , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , TrichostrongylusRESUMO
High-performance-validated tests are essential for successful epidemiological monitoring, surveillance of parasitic infections, and comparative studies in wildlife populations. The Mini-FLOTAC is a novel flotation-based technique for the sensitive detection and quantification of gastrointestinal parasites that is recently being explored for use in wildlife. A limitation of any flotation-based copromicroscopic method is the selection of the flotation solution (FS), which might influence the performance of the test. However, no study has compared the influence of using different FS in the Mini-FLOTAC technique for parasite detection in wild birds. Here, we evaluated the diagnostic performance of the Mini-FLOTAC in three waterbird host species using two widely used FS: saturated salt (NaCl; specific gravity 1.20) and saturated zinc sulfate (ZnSO4; specific gravity 1.35). One hundred fresh fecal samples were analyzed for parasite fecal egg counts (FEC). Regardless of the host species, fecal samples evaluated with the Mini-FLOTAC method using ZnSO4 resulted in a significantly higher detection rate and higher FEC of strongylid, capillarid, cestode, and trematode parasites, than samples analyzed with the NaCl solution. Our concise study demonstrated the importance of using an appropriate FS for the identification of parasite eggs in wildlife species, especially in hosts with an expected aggregated distribution and low parasite load such as waterbird hosts. The higher analytical sensitivity of the Mini-FLOTAC technique achieved with ZnSO4, and its applicability to fieldwork, highlights this method as a promising tool for the quantitative surveillance of parasite infections in wild bird populations.
Assuntos
Aves/parasitologia , Helmintos , Enteropatias Parasitárias , Animais , Animais Selvagens/parasitologia , Fezes/parasitologia , Helmintos/isolamento & purificação , Enteropatias Parasitárias/diagnóstico , Enteropatias Parasitárias/veterinária , Contagem de Ovos de Parasitas , Sensibilidade e EspecificidadeRESUMO
Resumen Debido al uso frecuente del triclabendazol (TCBZ) por parte de los productores, sumado al reporte reciente de resistencia de Fasciolahepatica al fármaco detectada en rodeos y majadas de Neuquén, se llevó a cabo el presente trabajo con el objetivo de evaluar la eficacia del TCBZ como fasciolicida en caprinos bajo un sistema de producción trashumante del norte de la provincia de Neuquén, Argentina. La eficacia se evaluó mediante un test de reducción de conteo de huevos de F. hepatica en caprinos Criollo Neuquino parasitados naturalmente. Se utilizaron dos grupos de animales: un Grupo Control (n: 10) que no recibió tratamiento y un Grupo Tratado (n: 10) al que se le administró TCBZ al 10% (Biofasiolex T10-Biogénesis Bagó ®) vía oral a dosis de 10 mg/kg PV. Al día 0 y 21 post tratamiento, se tomaron muestras de materia fecal para análisis coproparasitológicos. Se evidenció una reducción del conteo de huevos de F. hepatica del 100%, indicando el mantenimiento de la eficacia del fasciolicida en los caprinos evaluados. Se discuten los alcances del uso del test de reducción de conteo de huevos en zonas con producción trashumante del ganado.
Abstract Because of the frequent use of triclabendazole TCBZ by farmers and the recent reports of Fasciola hepatica resistance to this drug in herds and flocks from Neuquén, we carried out this study with the aim to evaluate the efficacy of TCBZ as fasciolicide in goats under a transhumance system from northern of Neuquén, Argentina. A fecal egg count reduction test (FECRT) was performed on Creale Neuquino goats naturally parasitized with F. hepatica. Twenty goats were divided into two groups: A control group (n: 10) which was left untreated, and a treatment group (n: 10) that was dosed orally with TCBZ 10% (Biofasiolex T10-Biogénesis Bagó ®). On Day 0 and Day 21 post-treatment, fecal samples were taken and analyzed by coproscopical examination. According to the FECRT, drug efficacy was 100 % and confirms that TCBZ maintains its efficacy against F. hepatica on goats. The usefulness of the FECRT in these zones under transhumance livestock production is discussed.
RESUMO
Gastrointestinal nematodes (GIN) constitute a problem in many sheep production systems, including those in Uruguay, causing reduced productivity and increased expenses. The main strategy to control GIN has consisted of the use of anthelmintics. However, GINs have developed resistance to anthelmintics, reducing their effectiveness. Genetic resistance to GINs has been found in flocks of different breeds. To date, there have been no reports about GINs breaking down genetic resistance in sheep. Heritability estimates of resistance to GIN within breeds are generally moderate, so that achieving genetic gain within a flock is possible. In this study, we predicted genetic gain in worm egg count (WEC), an indirect (and generally preferred) criterion of resistance to GIN, following different strategies. A multi-trait breeding objective including wool and meat traits was assumed and genetic gain over 10 years of selection in a Merino flock was estimated. We used a desired gains approach, examining situations in which the economic contribution of genetic gain in resistance to GIN in percentage terms was 0, 25, 50, 75 or 100. Except when the level of infestation with GIN was low, a considerable amount of emphasis had to be placed on selection for low WEC in order to reach the threshold below which the administration of anthelmintics is not required. High emphasis on reducing WEC lead to a reduction in genetic gain in wool and meat traits, or to their deterioration in the extreme case of 100 per cent emphasis on WEC. Given this finding, coupled with the difficulties encountered in accurately recording and selecting for WEC, we concluded that in addition to embarking upon a programme of within flock selection, sheep breeders interested in improving genetic resistance to GIN should also consider using breeding stock identified as superior for both resistance and production traits in across flock genetic evaluations.
Assuntos
Anti-Helmínticos , Nematoides , Doenças dos Ovinos , Animais , Anti-Helmínticos/uso terapêutico , Fezes , Ovinos/genética , Doenças dos Ovinos/genética , Carneiro DomésticoRESUMO
Abstract This study was performed to assess the possible relationship between gastrointestinal strongylid infections and milk quantity and quality in donkeys used for milk production. Individual fecal and milk samples were collected from 16 multiparous lactating jennies of Amiatina breed at their 6th month of lactation. Statistical analysis was carried out between strongylid eggs per gram of faeces (EPG) and milk parameters. All animals were found to shed cyathostomin eggs, with EPG ranging from 150 to 1900. A higher milk production was observed in animals showing an EPG< 250, but this result was statistically not significant. Conversely, significant higher concentrations of milk urea and pH values, and lower concentrations of milk lactose, were observed in jennies with an EPG >1000. In conclusion, results from this study suggest that cyathostomin EPG values > 1000 may affect milk quality in dairy donkeys. Considering the novelty of these findings, more data needs to be collected to determine EPG thresholds to be used as a good marker for parasite infections influencing milk performance and quality in donkeys.
Resumo Este estudo foi realizado com o objetivo de determinar a possível relação entre a infecção por estrongilídeos gastrintestinais e a quantidade e qualidade do leite de jumentas em lactação. Amostras individuais de fezes e leite foram coletados em 16 jumentas multíparas e lactantes da raça Amiatina no seu sexto mês de lactação. A análise estatística foi realizada entre a contagem de ovos de Cyathostominae por grama de fezes (OPG) e parâmetros do leite. Todos os animais estavam eliminando Cyathostominae nos ovos das fezes amostradas, variando entre 150 a 1.900 OPG. Embora não estatisticamente significativo, houve uma maior produção de leite em animais com OPG < 250. Inversamente, houve um aumento significativo na concentração de ureia e pH no leite, e baixa concentração de lactose foi observada nas jumentas com OPG > 1.000. Em conclusão, os resultados deste estudo sugerem que valores de OPG > 1.000 para ovos de Cyathostominae, podem comprometer a qualidade do leite em jumentas lactantes. Essa informação é original e mais dados necessitam ser obtidos para determinar os limites de OPG que poderão ser usados como marcadores para infecção parasitária, bem como na qualidade e "performance" de jumentas.
Assuntos
Animais , Feminino , Lactação , Leite , Contagem de Ovos de Parasitas/veterinária , Equidae , FezesRESUMO
Characterized as the most important gastrointestinal parasite (GIP) in the world, Haemonchus contortus is also the most predominant and pathogenic genus in Uruguay, causing high morbidity and mortality rates in sheep flocks. For approximately 26 years resistance to GIP has been included in the National Genetic Evaluation (NGE) of Corriedale and Merino breeds, using Faecal Egg Count (FEC) as the selection criterion. The aim of the present study was to estimate genetic parameters for FEC, post-weaning Body Weight (BW), Packed Cell Volume (PCV), FAMACHA© and Body Condition Score (BCS), to determine the possibility to include these traits in the NGE of GIP resistance and resilience, as complementary selection criteria and to investigate the sensitivity of breeding values to different environmental worm burden challenges. Data were collected on 19,510 lambs from 2000 to 2009 in 24 Corriedale studs that participated in the NGE of sheep in Uruguay. (Co)variances components were estimated using a multi-trait animal model performing a Bayesian analysis. Posterior means estimated for heritability (h2) were of low to moderate magnitude (between 0.10 and 0.33) for the traits analysed. Genetic correlations (rg) were not significantly different from zero for BW- Loge (FECâ¯+â¯100), BW-FAMACHA©, BW-PCV, Loge (FECâ¯+â¯100)-PCV, BCS-FAMACHA©, moderate favourable rg for Loge (FECâ¯+â¯100)-FAMACHA and PCV-BCS (0.55, 0.41) and high favourable rg for BW-BCS (0.66). These results indicate the possibility to complement selection programs incorporating BW, Loge (FECâ¯+â¯100), FAMACHA©, PCV and BCS in order to select resistant and resilient animal to GIP. Furthermore, genetic parameters for BW and Loge (FECâ¯+â¯100) to different environmental worm burden challenge was investigated. Two contemporary groups of low worm environment (Loge (FECâ¯+â¯100) below 6.40) and a high worm environment (Loge (FECâ¯+â¯100) above 6.75) were considered. In this model, h2 estimated for BW and Loge (FECâ¯+â¯100) were found to be not statistically different between low and high environmental worm burden, furthermore, high correlations between traits at both environments were also presented.
RESUMO
This study evaluated the effect of climatic conditions on the occurrence of Eimeria sp., strongylids and Moniezia sp. by analyzing the excretion of eggs and oocysts in the feces of sheep. In all, 3,509 coproparasitological examinations were performed after the monthly collection of feces of 121 sheep for 29 months. The meteorological data collected were rainfall, insolation, evapotranspiration, relative humidity, and temperature. Principal component analysis was performed to summarize the number of climatic variables. To evaluate the climatic vectors that influenced the variables, Eimeria sp., strongylids and Moniezia sp., a spatial projection of the ordination of vectors on the first two principal components was performed. To evaluate the mean values of the variables, Eimeria sp., strongylids and Moniezia sp., a cluster analysis was performed (k-means clustering), according to the categories. An association of Eimeria sp. and strongylids with relative humidity and rainfall was observed. Moniezia sp. was also related to the minimum temperature. The prevalence of Moniezia sp. was the least affected by relative humidity, rainfall, insolation, and evapotranspiration. The highest counts of endoparasites were observed in the offspring category and in the months of higher rainfall.
Este estudo avaliou o efeito das condições climáticas na ocorrência de Eimeria sp., e strongilídeos e Moniezia sp. analisando a eliminação de ovos e oocistos nas fezes de ovinos. Ao todo, 3.509 exames coproparasitológicos foram realizados após a coleta mensal de fezes de 121 ovinos durante 29 meses. Os dados meteorológicos coletados foram precipitação, insolação, evapotranspiração, umidade relativa e temperatura. A análise de componentes principais foi realizada para resumir o número de variáveis climáticas. Para avaliar os vetores climáticos que influenciaram as variáveis, Eimeria sp., estrongilídeos e Moniezia sp., foi realizada uma projeção espacial da ordenação dos vetores nos dois primeiros componentes principais. Para avaliar os valores médios das variáveis, Eimeria sp., estrongilídeos e Moniezia sp., foi realizada uma análise de agrupamento (k-means clustering) de acordo com as categorias. Uma associação de Eimeria sp. e estrongilídeos com umidade relativa e precipitação foi observada. Moniezia sp. foi relacionada à temperatura mínima. A prevalência de Moniezia sp. foi a menos afetada pela umidade relativa, precipitação, insolação e evapotranspiração. As maiores contagens de endoparasitas foram observadas na categoria de criase nos meses de maior pluviosidade.
Assuntos
Animais , Efeitos do Clima , Gastroenteropatias/parasitologia , Gastroenteropatias/veterinária , Ovinos/parasitologia , Contagem de Ovos de Parasitas/veterinária , Estação ChuvosaRESUMO
This study evaluated the effect of climatic conditions on the occurrence of Eimeria sp., strongylids and Moniezia sp. by analyzing the excretion of eggs and oocysts in the feces of sheep. In all, 3,509 coproparasitological examinations were performed after the monthly collection of feces of 121 sheep for 29 months. The meteorological data collected were rainfall, insolation, evapotranspiration, relative humidity, and temperature. Principal component analysis was performed to summarize the number of climatic variables. To evaluate the climatic vectors that influenced the variables, Eimeria sp., strongylids and Moniezia sp., a spatial projection of the ordination of vectors on the first two principal components was performed. To evaluate the mean values of the variables, Eimeria sp., strongylids and Moniezia sp., a cluster analysis was performed (k-means clustering), according to the categories. An association of Eimeria sp. and strongylids with relative humidity and rainfall was observed. Moniezia sp. was also related to the minimum temperature. The prevalence of Moniezia sp. was the least affected by relative humidity, rainfall, insolation, and evapotranspiration. The highest counts of endoparasites were observed in the offspring category and in the months of higher rainfall.(AU)
Este estudo avaliou o efeito das condições climáticas na ocorrência de Eimeria sp., e strongilídeos e Moniezia sp. analisando a eliminação de ovos e oocistos nas fezes de ovinos. Ao todo, 3.509 exames coproparasitológicos foram realizados após a coleta mensal de fezes de 121 ovinos durante 29 meses. Os dados meteorológicos coletados foram precipitação, insolação, evapotranspiração, umidade relativa e temperatura. A análise de componentes principais foi realizada para resumir o número de variáveis climáticas. Para avaliar os vetores climáticos que influenciaram as variáveis, Eimeria sp., estrongilídeos e Moniezia sp., foi realizada uma projeção espacial da ordenação dos vetores nos dois primeiros componentes principais. Para avaliar os valores médios das variáveis, Eimeria sp., estrongilídeos e Moniezia sp., foi realizada uma análise de agrupamento (k-means clustering) de acordo com as categorias. Uma associação de Eimeria sp. e estrongilídeos com umidade relativa e precipitação foi observada. Moniezia sp. foi relacionada à temperatura mínima. A prevalência de Moniezia sp. foi a menos afetada pela umidade relativa, precipitação, insolação e evapotranspiração. As maiores contagens de endoparasitas foram observadas na categoria de criase nos meses de maior pluviosidade.(AU)
Assuntos
Animais , Ovinos/parasitologia , Gastroenteropatias/veterinária , Gastroenteropatias/parasitologia , Efeitos do Clima , Contagem de Ovos de Parasitas/veterinária , Estação ChuvosaRESUMO
Routine faecal examination of a herd of weaned male goats revealed heavy infections with gastrointestinal strongyles (GIS) and Strongyloides sp. Moxidectin (routinely dosed at 0.3â¯mg·kg-1, i.e., 1.5 times the sheep dose), although fully effective against GIS, failed to control Strongyloides sp., with an estimated faecal egg count reduction (FECR) of only 55.5%. In addition, levamisole (11.25â¯mg·kg-1) and ivermectin (0.3â¯mg·kg-1) also failed to control Strongyloides sp., with FECRs of 1.4% and 53.5%, respectively. On the other hand, albendazole (7.5â¯mg·kg-1) and netobimin (11.25â¯mg·kg-1 and 22.5â¯mg·kg-1) reduced by 96.3-99.9% the Strongyloides sp. faecal egg counts according to dose and remained effective, although, in the past, this drug family has been used extensively on the same farm and was no longer effective against GIS. Albendazole or netobimin at 3 times the dose for sheep may be effective for Strongyloides sp. control in case of severe infection.
Assuntos
Anti-Helmínticos/uso terapêutico , Surtos de Doenças/veterinária , Doenças das Cabras/tratamento farmacológico , Strongyloides/efeitos dos fármacos , Estrongiloidíase/veterinária , Fatores Etários , Albendazol/uso terapêutico , Animais , Anti-Helmínticos/administração & dosagem , Resistência a Medicamentos , Fezes/parasitologia , Doenças das Cabras/parasitologia , Cabras/parasitologia , Guadalupe/epidemiologia , Ivermectina/uso terapêutico , Levamisol/uso terapêutico , Macrolídeos/uso terapêutico , Masculino , Contagem de Ovos de Parasitas/veterinária , Estrongiloidíase/epidemiologia , Resultado do Tratamento , Clima TropicalRESUMO
Resumen Introducción. La técnica de Kato Katz es el método recomendado para realizar el recuento de huevos en materia fecal y determinar la intensidad parasitaria por helmintos. La calidad de los resultados se ve afectada por la tardanza en el procesamiento de la muestra, por lo que se requiere de preservantes que faciliten la lectura posterior a las 24 horas de recolección de la muestra. Objetivo. Demostrar validez de la solución con acetato de sodio-ácido acético-formalina (SAF) como preservante de huevos de Necator americanus por medio del estudio de un caso clinico. Materiales y métodos. Descripción de caso clínico con diagnóstico de parásitos intestinales por coprológico, intensidad de la infección por la técnica de Kato Katz, evaluación de la presencia de huevos N. americanus por la técnica de Kato Katz durante 10 meses en muestra preservada en SAF y determinación de especie de Uncinaria sp. por qPCR. Resultados. Los huevos de N. americanus se conservan de manera adecuada en morfología durante los primeros cinco meses. Conclusiones. A fin de ejecutar la técnica de Kato Katz, la fijación con SAF demostró ser adecuada para el mantenimiento de la intensidad parasitaria y morfología de los huevos de N. americanus en un período de hasta cinco meses.
Abstract Introduction: The Kato Katz technique is the recommended method for fecal egg counts and determining the intensity of parasitic helminths. The quality of the results is affected by the delay in the analysis of the sample. Therefore, fixatives are necessary to make the reading easier 24 hours after sample collection. Objective: To prove the usefulness of sodium acetate-acetic acid-formalin (SAF) solution as a fixative for Necator americanus eggs by means of a clinical case study. Materials and methods: Clinical case description and intestinal parasites diagnosis by direct stool microscopic analysis and parasite infection intensity by means of the Kato Katz technique. N. americanus eggs were detected by Kato Katz method for 10 months on a SAF-fixed stool sample. Identification of Uncinaria sp. by qPCR. Results: N. americanus eggs are adequately preserved in SAF during the first five months. Conclusions: SAF fixative is suitable for Kato Katz method and proved to be capable of maintaining parasite intensity and N. americanus egg morphology over a period of up to five months.
RESUMO
The prevalence of gastrointestinal (GI) nematodes and total worm burden of Damara and Barbados Blackbelly cross sheep was investigated among smallholder farms in Salak Tinggi district of Selangor, Malaysia. A total of 50 sheep raised in smallholder farms comprising of 27 Damara cross and 23 Barbados Blackbelly cross were categorized based on their age into young and adults. Fecal samples were collected and examined for strongyle egg count by using modified McMaster technique. Severity of infection was categorized into mild, moderate, and heavy, based on egg per gram (EPG). Five sheep were randomly selected and slaughtered to examine the presence of adult gastrointestinal (GI) nematodes through total worm count (TWC). Faffa Malan Chart (FAMACHA) score was used for investigation of worm load based on the degree of anemia. The study revealed an overall EPG prevalence of 88 %, of which 84.1 % had mild infection. There was a significant difference (p = 0.002) in EPG among the two breeds. Based on age, significant difference (p = 0. 004) in EPG was observed among Barbados Blackbelly cross, but not for Damara cross (p = 0.941). The correlation between severity of infection and the FAMACHA score was significant (r = 0.289; p = 0.042). Haemonchus spp. were the most predominant nematode found in the gastrointestinal tract, followed by Trichostrongylus and Oesophagostomum spps. EPG and TWC for Haemonchus were positively correlated, but not significant (r = 0.85, p = 0.066). From regression analysis, 73 % of the variability in TWC for Haemonchus could be explained by EPG. Thus, it can be concluded that FAMACHA score correlates well with severity of infection of a nematode and can be used to assess the strongyle nematode burden in the different sheep crosses.
Assuntos
Gastroenteropatias/veterinária , Doenças dos Ovinos/epidemiologia , Infecções por Strongylida/veterinária , Estrongilídios/isolamento & purificação , Animais , Fezes/parasitologia , Gastroenteropatias/epidemiologia , Gastroenteropatias/parasitologia , Malásia/epidemiologia , Contagem de Ovos de Parasitas/veterinária , Prevalência , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro Doméstico , Infecções por Strongylida/epidemiologia , Infecções por Strongylida/parasitologiaRESUMO
Haemonchus contortus is a blood-sucking parasite causing the presence of faecal occult blood (FOB). The objective was to study three different FOB tests in order to have a new indicator of H. contortus infection in sheep that could be included in the genetic evaluation system as an alternative selection criterion to faecal worm egg count (FEC). A total of 29 Corriedale lambs were experimentally infected with 10.000 larvae of H. contortus. Stool samples were recorded for FEC and FOB tests (Hexagon, Hematest(®) and Multistix(®)), blood for packed cell volume (PCV), haemoglobin, white and red blood cell count (RBC), and FAMACHA(©) for scoring anaemia. At the end of the experiment lambs were slaughtered to worm burden count. Field infection was achieved in 309 Merino lambs under natural parasite challenge. FEC data were normalized through logarithmic transformation (LnFEC). Pearson correlation was estimated to examine the relationship between all traits. The three tests were able to detect the presence of FOB at day 11. FEC, PCV and RBC decreased to sub-normal values from day 18. FAMACHA(©) score 3 was considered to be indicative of anaemia. Most of the correlations were of high magnitude, with the exception of Multistix(®) test that was moderately correlated with haematological parameters, LnFEC and FEC. In field infection, most samples were negative to FOB tests and the correlations were lower than those calculated under experimental infection. In conclusion, FOB tests were able to detect haemonchosis earlier than FEC under high experimental parasite challenge. However, they were not able to detect FOB under natural mixed parasite challenge. FAMACHA(©) and PCV demonstrated to be good indicators of Haemonchosis, having moderate to high correlations with FEC.
RESUMO
This experiment was carried out on 8 ha of Panicum maximum cv. Tanzania pastures, with rotational grazing consisting of 7 days of occupation and 21 days of rest. Four treatments were evaluated: cattle grazing alone (BOV), sheep grazing alone (OVI), cattle and sheep grazing simultaneously (SIM) and cattle grazing followed by sheep (alternate - ALT). Twenty heifers and 30 male Santa Inês lambs were used. Fecal egg count (FEC) and fecal cultures were carried out. Blood was also collected to examine red and white cell series, total plasma protein (TPP), albumin and hemoglobin. FEC and estimated nematode pathogenicity index in sheep were lower in the SIM treatment. The Haemonchus spp. proportion was higher in isolated grazing systems. For sheep, mixed grazing was shown to reduce endoparasite infection, and SIM was better than ALT. For cattle, no difference between grazing systems was seen. Therefore, simultaneous grazing (sheep and cattle) may be a tool for reducing the need for anthelmintic treatments in sheep.
O experimento foi realizado em 8ha de pasto de Panicum maximum cv. Tanzania, com pastejo rotacionado de 7 dias de ocupação e 21 dias de descanso. Quatro tratamentos foram avaliados: bovinos pastejando isoladamente (BOV), ovinos pastejando isoladamente (OVI), bovinos e ovinos pastejando simultaneamente (SIM), e bovinos pastejando previamente aos ovinos (alternado - ALT). Vinte novilhas e 30 cordeiros Santa Inês foram utilizados. Contagem de ovos nas fezes (FEC) e coproculturas foram realizados. Sangue também foi colhido para examinar a série vermelha e branca, proteínas plasmáticas totais (TPP), albumina e hemoglobina. FEC e índice de patogenicidade estimada de nematoides nos ovinos foram menores no tratamento SIM. A proporção de Haemonchus spp. foi maior nos sistemas isolados de pastejo. Para os ovinos, os sistemas consorciados apresentaram redução na infecção endoparasitária, sendo SIM melhor que ALT. Para os bovinos, nenhuma diferença entre os sistemas de pastejo foi verificado. Entretanto, o pastejo simultâneo (ovinos e bovinos) pode ser uma ferramenta para reduzir a necessidade de tratamentos anti-helmínticos em ovinos.
Assuntos
Animais , Masculino , Bovinos , Contagem de Ovos de Parasitas/veterinária , Fezes/parasitologia , Haemonchus , Doenças dos Bovinos/parasitologia , Herbivoria , Doenças dos Ovinos/parasitologia , Doenças dos Bovinos/epidemiologia , Ovinos , Doenças dos Ovinos/epidemiologia , Fatores de TempoRESUMO
This experiment was carried out on 8 ha of Panicum maximum cv. Tanzania pastures, with rotational grazing consisting of 7 days of occupation and 21 days of rest. Four treatments were evaluated: cattle grazing alone (BOV), sheep grazing alone (OVI), cattle and sheep grazing simultaneously (SIM) and cattle grazing followed by sheep (alternate - ALT). Twenty heifers and 30 male Santa Inês lambs were used. Fecal egg count (FEC) and fecal cultures were carried out. Blood was also collected to examine red and white cell series, total plasma protein (TPP), albumin and hemoglobin. FEC and estimated nematode pathogenicity index in sheep were lower in the SIM treatment. The Haemonchus spp. proportion was higher in isolated grazing systems. For sheep, mixed grazing was shown to reduce endoparasite infection, and SIM was better than ALT. For cattle, no difference between grazing systems was seen. Therefore, simultaneous grazing (sheep and cattle) may be a tool for reducing the need for anthelmintic treatments in sheep.
O experimento foi realizado em 8ha de pasto de Panicum maximum cv. Tanzania, com pastejo rotacionado de 7 dias de ocupação e 21 dias de descanso. Quatro tratamentos foram avaliados: bovinos pastejando isoladamente (BOV), ovinos pastejando isoladamente (OVI), bovinos e ovinos pastejando simultaneamente (SIM), e bovinos pastejando previamente aos ovinos (alternado - ALT). Vinte novilhas e 30 cordeiros Santa Inês foram utilizados. Contagem de ovos nas fezes (FEC) e coproculturas foram realizados. Sangue também foi colhido para examinar a série vermelha e branca, proteínas plasmáticas totais (TPP), albumina e hemoglobina. FEC e índice de patogenicidade estimada de nematoides nos ovinos foram menores no tratamento SIM. A proporção de Haemonchus spp. foi maior nos sistemas isolados de pastejo. Para os ovinos, os sistemas consorciados apresentaram redução na infecção endoparasitária, sendo SIM melhor que ALT. Para os bovinos, nenhuma diferença entre os sistemas de pastejo foi verificado. Entretanto, o pastejo simultâneo (ovinos e bovinos) pode ser uma ferramenta para reduzir a necessidade de tratamentos anti-helmínticos em ovinos.
RESUMO
Accurate genetic evaluation of livestock is based on appropriate modeling of phenotypic measurements. In ruminants, fecal egg count (FEC) is commonly used to measure resistance to nematodes. FEC values are not normally distributed and logarithmic transformations have been used in an effort to achieve normality before analysis. However, the transformed data are often still not normally distributed, especially when data are extremely skewed. A series of repeated FEC measurements may provide information about the population dynamics of a group or individual. A total of 6375 FEC measures were obtained for 410 animals between 1992 and 2003 from the Beltsville Agricultural Research Center Angus herd. Original data were transformed using an extension of the Box-Cox transformation to approach normality and to estimate (co)variance components. We also proposed using random regression models (RRM) for genetic and non-genetic studies of FEC. Phenotypes were analyzed using RRM and restricted maximum likelihood. Within the different orders of Legendre polynomials used, those with more parameters (order 4) adjusted FEC data best. Results indicated that the transformation of FEC data utilizing the Box-Cox transformation family was effective in reducing the skewness and kurtosis, and dramatically increased estimates of heritability, and measurements of FEC obtained in the period between 12 and 26 weeks in a 26-week experimental challenge period are genetically correlated.
RESUMO
The aim of this study was to evaluate the potential uses of acacia extract (AE) on Trichostrongylus colubriformis control in sheep. The lambs were allocated in three groups of six animals. Two groups were experimentally infected with third-stage larvae of T. colubriformis and one was remained as non-infected control. Thirty days post-infection, the infected animals from treated group were supplemented with AE. During and after the treatment, the values of faecal eggs counts (FEC), number of third-stage larvae recovered per gram of faeces (LPG), number of FEC accumulated per animal during the treatment period, nematode egg viability, and worm burden were determined. Animals from non-infected group did not presented FEC values, during the experimental period. The average of total accumulated amount of FEC output per group, during the 10 days of the treatment was lower in AE treated lambs (P<0.05). The values of egg viability were statistically reduced (P<0.05) on days 4, 7 and 10 post treatment (p.t.). The number of LPG was lower (P<0.05), at the days 10 and 14p.t., in treated animals. AE showed potential to be used on the prophylaxis of gastrointestinal nematode infections in sheep.
O objetivo deste trabalho foi avaliar o potencial do extrato de acácia (EA) para o controle de T. colubriformis em ovinos. Os cordeiros foram alocados em três grupos de seis animais. Dois grupos foram experimentalmente infectados com larvas infectantes de T. colubriformis, sendo um grupo mantido como controle não infectado. Trinta dias pós-infecção, os animais infectados do grupo tratado foram suplementados com EA. Durante e após o tratamento os valores de contagem de ovos por grama de fezes (OPG), número de larvas de terceiro estágio por grama de fezes (LPG), número de OPG eliminado por animal durante o período de tratamento, viabilidade dos ovos e carga parasitária foram determinados. Os animais do grupo não infectado permaneceram com número de OPG igual a zero durante todo o período experimental. A média do número de OPG total eliminado por grupo, somatória durante os 10 dias de tratamento, foi menor nos cordeiros tratados com EA (P<0,05). Os valores de viabilidade dos ovos de helmintos foram menores (P<0,05) nos dias 4, 7 e 10 pós-tratamento (p.t.). O número de LPG foi menor (P<0,05), nos dias 10 e 14p.t., no grupo tratado. O EA demonstrou potencial para sua utilização no controle de T. colubriformis em ovinos.