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1.
Ann Parasitol ; 67(2): 187-194, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34332192

RESUMO

Gastrointestinal (GI) parasites are major contributors to decrease productivity in livestock over the world. A cross-sectional study was conducted in different areas of Bangladesh to determine the prevalence of GI parasitic infections and their association with the biotic and abiotic factors in sheep. A total of 572 faecal samples were collected from the selected areas of Bangladesh and microscopic examination was performed for the identification of parasites using flotation and sedimentation technique. Out of 572, 441 animals were found infected with one or more species of GI parasites with an overall prevalence of 77.1%. Nine types of parasites from four different classes were detected namely Strongyles (42.1%), Strongyloides sp. (27.1%) and Trichuris sp. (1.0%), Moniezia sp. (2.4%), Paramphistomum cervi (32.5%), Fasciola gigantica (6.1%) and Schistosoma sp. (3.5%), coccidia (16.6%) and Balantidium coli (7.9%). Nematodes infections (56.8%) were significantly highest among trematodes (37.9%), protozoa (24.4%) and cestode (2.4%). In the present study, all the biotic factors including sex, age, physiological condition of female and body condition score (BCS) of animals were insignificantly (p>0.05) associated with the prevalence of GI parasitic infection in sheep but among the abiotic factors, muddy housing of animals, rainy season, having no knowledge about GI parasites and illiteracy of farmers were significantly (p<0.05) associated with the GI parasitic infections. This epidemiological investigation will assist to build a suitable control program against GI parasites in sheep and thus, help to prevent production loss and increase livelihood of small holder farmers.


Assuntos
Enteropatias Parasitárias , Infecções por Nematoides , Parasitos , Doenças dos Ovinos , Animais , Bangladesh/epidemiologia , Estudos Transversais , Fezes , Feminino , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/veterinária , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/veterinária , Prevalência , Ovinos , Doenças dos Ovinos/epidemiologia
2.
J Zoo Wildl Med ; 52(2): 849-852, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34130435

RESUMO

A 5-y-old female lined flat-tail gecko (Uroplatus lineatus) presented for acute onset of lethargy and paraplegia and was subsequently euthanized. Histologic examination of the spinal cord revealed a verminous myelitis comprising moderate, multifocal, necrotizing myelitis with intramedullary adult and larval nematodes. Molecular data and morphology indicate a cosmocercid nematode, most likely of the genus Raillietnema, a diverse taxon reported to parasitize reptiles, amphibians, and teleost fish. To the authors' knowledge this is the first report of spinal nematodiasis in a reptile species, and the first report of spinal parasitism causing hind-limb paraplegia in a reptile.


Assuntos
Lagartos/parasitologia , Infecções por Nematoides/veterinária , Doenças da Medula Espinal/veterinária , Animais , Feminino , Infecções por Nematoides/parasitologia , Infecções por Nematoides/patologia , Doenças da Medula Espinal/parasitologia , Doenças da Medula Espinal/patologia
3.
Animal ; 15(6): 100237, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34091226

RESUMO

Sickness behaviour has been suggested as an applicable indicator for monitoring disease. Deviating feeding behaviour and activity can provide information about animals' health and welfare status. Recent advances in sensor technology enable monitoring of such behaviours and could potentially be utilized as an indicator of gastrointestinal nematode (GIN) infections. This study investigated activity and rumination patterns in first-season grazing steers exposed to subclinical infection levels of the GIN Ostertagia ostertagi and Cooperia oncophora. At turnout, animals were allocated to one of four experimental groups and were faced with "high" (H1, n = 15; H2, n = 17) or "low" (L1, n = 17; L2, n = 11) levels of parasite exposure by grazing in similar enclosures contaminated with overwintering third stage (L3) GIN larvae. Animals in H1 and H2 (HP) received a 1:1 mix of approximately 10,000 O. ostertagi and C. oncophora L3 at turnout; whereas the animals in L1 and L2 (LP) were treated monthly with ivermectin. Activity and rumination patterns were monitored by fitting animals with leg- (IceQube) and neck-mounted (Heatime) sensors. BW was recorded every fortnight, whereas faecal and blood samples were examined every four weeks for nematode faecal egg count and serum pepsinogen concentrations (SPCs). There was an interaction effect of exposure level and period (P < 0.0001) on average lying daily time across the entire grazing time. A higher mean daily lying time (P = 0.0037) was found in HP compared with LP during the first 40 days on pasture. There was also interaction effects of treatment and day since turnout on rumination time (P < 0.0001) and rumination change (P = 0.0008). Also mean daily steps (P < 0.0001) and mean daily motion index (P < 0.0001) were markedly higher in HP during days 62-69, coinciding with peaking SPC in HP. Strongyle eggs were observed both in HP and LP from 31 days after turnout. Eggs per gram (EPG) differed between parasite exposure levels (P < 0.0001), with mean EPG remaining low in LP throughout the experiment. Similarly, an increase in SPC was observed (P < 0.0001), but only in HP where it peaked at day 56. In contrast, no difference in BW gain (BWG) (P = 0.78) between HP and LP was observed. In conclusion, this study shows that behavioural measurements monitored with sensors were affected even at low infection levels not affecting BWG. These combined results demonstrate the potential of automated behavioural recordings as a tool for detection of subclinical parasitism.


Assuntos
Doenças dos Bovinos , Nematoides , Infecções por Nematoides , Animais , Bovinos , Fezes , Infecções por Nematoides/veterinária , Óvulo , Contagem de Ovos de Parasitas/veterinária , Estações do Ano
4.
Acta Vet Scand ; 63(1): 18, 2021 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-33906690

RESUMO

Gastrointestinal nematodes (GIN) in small ruminants result in production losses, and consequently economic losses, and are an animal welfare problem in most countries in the Nordic-Baltic region. Intensive use of anthelmintics to control helminth infections has led to anthelmintic resistance (AR), which has become a major issue in many European countries. Several studies have been performed in countries in the Nordic-Baltic region (e.g. Denmark, Sweden, Norway and Lithuania) showing increasing/emerging levels of AR. The aim of this paper is to provide an overview of the problem of AR on sheep and goat farms in the Nordic-Baltic region. This region has a limited number of registered anthelmintics. However, researchers in this area have discovered some surprising findings, such as ivermectin (IVM) resistance on a farm that had never used IVM. In Sweden there is evidence of macrocyclic lactone (ML)-resistant Haemonchus contortus being introduced with sheep imported from the Netherlands. As elsewhere in the world, the livestock trade appears to be contributing to the spread of AR in the region and isolated cases of multidrug-resistant cases have also been reported. This is surprising given that the frequency of treatments here is much lower than in other countries where sheep production is economically more important. The prevailing nematodes are Haemonchus, Teledorsagia and Trichostrongylus, while on some farms Haemonchus is dominant and clinical haemonchosis has increasingly been observed in recent decades. The reasons for this are unclear, but are probably related to this parasite's propensity to rapidly develop drug resistance and a general lack of awareness of the problem, possibly in combination with global warming and the increased livestock trade within the EU. In addition, domestic interactions through contacts with wildlife ruminants, alpacas may also be a contributing factor for transmission of AR.


Assuntos
Anti-Helmínticos/uso terapêutico , Resistência a Medicamentos , Doenças das Cabras/epidemiologia , Infecções por Nematoides/veterinária , Doenças dos Ovinos/epidemiologia , Animais , Anti-Helmínticos/farmacologia , Doenças das Cabras/tratamento farmacológico , Cabras , Lituânia/epidemiologia , Nematoides/efeitos dos fármacos , Infecções por Nematoides/tratamento farmacológico , Países Escandinavos e Nórdicos/epidemiologia , Ovinos , Doenças dos Ovinos/tratamento farmacológico
5.
Vet Parasitol ; 292: 109395, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33812344

RESUMO

The aim of this study was to assess the effect of pasture molluscicide treatment on the prevalence and severity of small lungworm infections, and the productivity of lambs grazing improved pastures in southeastern Australia. A randomised control field trial of 260 Merino-cross lambs was conducted on a commercially managed farm in South Australia with a history of high small lungworm prevalence. Separate groups of lambs rotationally grazed irrigated lucerne paddocks treated with iron chelate molluscicide or untreated control paddocks. Lambs were monitored every 2-6 weeks from weaning until slaughter with liveweight, lungworm and gastrointestinal nematode infection status measured. At slaughter indicators of small lungworm infection via inspection and carcass characteristics were assessed. The density of the intermediate host snail and lucerne pasture availability were also measured. There was a higher population of adult Prietocella barbara molluscs in the Control paddocks compared to the Treatment paddocks after molluscicide had been applied and prior to grazing commencing (206 vs. 14 snails/m2, respectively; P = 0.03; 95 % CI 8, 528). However, the overall mollusc density was similar between Control and Treatment. The prevalence of small lungworm infections was quite low during the trial (0-13 %), in both Control and Treatment lambs, except at day 94 when 48 % of 28 Control lambs were positive compared to none of 27 Treatment lambs (P < 0.001; 95 % CI 30, 66). A similar proportion of Treatment and Control lambs had evidence of small lungworm infection lesions at slaughter (both 67.8 %). Control lambs grew slightly faster than Treatment lambs, with an average daily gain of 202 (± 3 SEM) g/head/day for Control and 190 (± 4 SEM) for Treatment (P < 0.001) during the 112-day trial. Despite historic evidence of very high prevalence of lungworm infection in this region of southeastern Australia, iron chelate molluscicide treatment prior to lambs grazing the pasture had no demonstrable effect on the prevalence and severity of small lungworm infections, nor the productivity of lambs grazing these pastures. This study indicates that for a commercial sheep farm, additional molluscicide treatments of pastures after they are established, for the prevention of small lungworm infection, may not be warranted. Furthermore, requirements for more precisely monitoring snails are discussed.


Assuntos
Pneumopatias Parasitárias/veterinária , Moluscocidas/farmacologia , Doenças dos Ovinos/parasitologia , Animais , Pneumopatias Parasitárias/parasitologia , Pneumopatias Parasitárias/prevenção & controle , Moluscos/efeitos dos fármacos , Infecções por Nematoides/veterinária , Ovinos , Doenças dos Ovinos/prevenção & controle
6.
Acta Parasitol ; 66(3): 947-953, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33721185

RESUMO

PURPOSE: The main objective of this study was to assess the gastrointestinal parasitism in relation with the worm control practices (WCP) in dairy cattle in areas of major importance for dairy/milk production of Cameroon. METHODS: Fresh fecal samples were randomly collected from 402 cattle from August to October 2016 in North West Cameroon, and analyze using the McMaster technique. Data on WCP were collected using a questionnaire. RESULTS: A total of 11 parasites species were identified: Trichostrongylus sp. (5.97%); Oesophagostomum sp. (5.47%); Haemonchus sp. (2.48%); Bonostomum sp. (1.74); Cooperia sp. (1.49%). Toxocara sp (0.24%); Ostertagia sp. (0.50%); Nematodirus sp. (0.74%); Trichuris sp. (0.50%); Moniezia sp. (0.50%); Eimeria sp. (0.50%). The mean individual parasite load for helminthes and protozoa ranged from 100 to 400 eggs per gram of feces (epg) and 333-400 oocysts per gram of feces (opg), respectively. Most farmers (95.12%) used conventional drugs (Albendazole, Doramectin, Fenbendazole, Ivermectin.) to deworm animals as compared with traditional phytotherapy (e.g., Carica papaya leaves) (4.88%). The mean epg/opg in animals treated with conventional drugs was significantly higher (p < 0.05) than in those receiving traditional treatment. Animals treated less than four times a year with conventional drugs had the highest (p < 0.05) mean epg/opg compared with animals treated four to six times a year. CONCLUSION: This study suggests that treating at least four times a year with conventional drugs, and at least two times a year with traditional approaches could help reducing GIP burden in dairy cattle in North West Cameroon. Since the majority of farmers use conventional drugs, it is imperative for them to appropriately use these conventional drugs for a better control of GIP on their farms.


Assuntos
Doenças dos Bovinos , Eimeria , Haemonchus , Enteropatias Parasitárias , Infecções por Nematoides , Animais , Camarões/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Fezes , Enteropatias Parasitárias/tratamento farmacológico , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/veterinária , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/veterinária , Contagem de Ovos de Parasitas/veterinária
7.
BMC Vet Res ; 17(1): 106, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33663490

RESUMO

BACKGROUND: Strongylid nematode infections may negatively affect both animal health and welfare, with deleterious consequences for livestock productivity. Many farmers in recent decades have relied on anthelmintics as the sole strategy of control, but the intensive use of these chemotherapeutics has led to the development of anthelmintic resistance (AR). Knowledge of both the efficacy of anthelmintics and factors promoting AR are essential to effectively control nematode infections, but no information on these topics for goats in the Czech Republic (CR) is available. This survey aimed to determine the occurrence of AR at Czech goat farms and to identify risk factors for the development of AR. A total of 24 herds of dairy goats across the CR were evaluated using in vitro tests for detecting AR, and a questionnaire survey was carried out to evaluate factors associated with AR. RESULTS: Resistance against benzimidazoles was confirmed at 18 (75%) farms, and the level of resistance was high in four (22%) of the affected herds based on the egg hatch test. Ivermectin-resistant nematodes were detected in 13 (54%) herds using the larval development test; Teladorsagia/Trichostrongylus and Haemonchus were the predominant types of resistant larvae. Eight (62%) of the affected herds were evaluated as highly resistant to ivermectin. Eleven (46%) of the herds were resistant to both benzimidazoles and ivermectin. This report is the first on dual AR in the CR. A univariate logistic regression analysis indicated that a high stocking rate and farmer inexperience were significantly associated with ivermectin and benzimidazole resistance, respectively. CONCLUSIONS: The results of our survey suggest that AR is widespread amongst herds of dairy goats in the CR, likely due to inappropriate practices of pasture and health management. AR may be an issue for expanding dairy-goat production in the CR in the near future unless both veterinary practitioners and farmers widely adopt strategies to prevent the development of AR.


Assuntos
Anti-Helmínticos/farmacologia , Resistência a Medicamentos , Doenças das Cabras/parasitologia , Nematoides/efeitos dos fármacos , Infecções por Nematoides/veterinária , Animais , Benzimidazóis , República Tcheca , Indústria de Laticínios/métodos , Doenças das Cabras/tratamento farmacológico , Cabras , Ivermectina , Larva , Nematoides/crescimento & desenvolvimento , Infecções por Nematoides/tratamento farmacológico , Inquéritos e Questionários
8.
Animal ; 15(4): 100185, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33653675

RESUMO

Gastrointestinal parasitism is a global problem for grazing ruminants which can be addressed in a sustainable way through breeding animals to be more resistant to disease. This study estimates the genetic parameters of common and new disease phenotypes associated with natural nematode and coccidian infection in Scottish Blackface sheep to underpin future genetic improvement strategies for parasite control. Data on faecal egg counts (FEC) from different species of strongyle parasites and faecal oocyst counts (FOC) from coccidian parasites were collected on 3-month-old lambs together with a faecal soiling score in the breech area dagginess (DAG) and live weight (LWT). Faecal count data were obtained for Strongyles (FECS), Nematodirus (FECN) and Coccidia (FOC). Data from 3 731 lambs sampled between 2011 and 2017 were included. Faecal egg counts and DAG records were log-transformed prior to analysis. Data were analysed using linear mixed models. Average age at sampling was 92 days with a mean LWT of 24.5 kg. Faecal soiling was not evident in 69% of lambs. Coccidia were the most prevalent parasite (99.5%), while Strongyles and Nematodirus had a prevalence of 95.4% and 72.7%, respectively. Heritability estimates (±SE) were 0.16 ±â€¯0.03, 0.17 ±â€¯0.03, 0.09 ±â€¯0.03, 0.09 ±â€¯0.03 and 0.33 ±â€¯0.04 for FECS, FECN, FOC, DAG and LWT, respectively. Strongyles faecal egg count had a strong and positive genetic correlation with FECN (0.74 ±â€¯0.09) and a moderate positive correlation with FOC (0.39 ±â€¯0.15) while DAG was negatively genetically correlated with LWT (-0.33 ±â€¯0.15). The significant positive genetic correlations between FECS, FECN and FOC at 3 months of age show that co-selection of sheep for resistance to these different parasites is feasible. Selection for increased resistance to parasite infection is not expected to adversely affect live BW, as no significant antagonistic genetic correlations were found between LWT and FEC. There were significant antagonistic phenotypic and genetic relationships between DAG and LWT being -0.19 ±â€¯0.02 and -0.33 ±â€¯0.15, respectively, indicating that the expression of the manifestation of disease in lambs may be a more meaningful indicator of the impact of parasite burden on productivity.


Assuntos
Nematoides , Infecções por Nematoides , Doenças dos Ovinos , Animais , Fezes , Infecções por Nematoides/genética , Infecções por Nematoides/veterinária , Contagem de Ovos de Parasitas/veterinária , Carga Parasitária/veterinária , Fenótipo , Escócia , Ovinos , Doenças dos Ovinos/genética
9.
Parasitol Res ; 120(5): 1637-1648, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33712928

RESUMO

Two species of intestinal Capillariidae were hitherto known from the Neotropic cormorant Phalacrocorax brasilianus, Baruscapillaria spiculata (Freitas, 1933), and Baruscapillaria appendiculata (Freitas, 1933). The original descriptions are very short and brief, and further reports of both species are scarce and/or confusing. This paper provides a morphological redescription and molecular characterization, based on the partial 18S rDNA gene, of B. spiculata specimens parasitizing the Neotropic cormorant in two continental lagoons from Buenos Aires province, Argentina. Both morphological and morphometrical differences between B. spiculata and B. appendiculata are highlighted on the examination of available type material. Additionally, two previous reports of B. appendiculata from Mexico and Brazil are discussed. A phylogenetic analysis conducted on specimens of B. spiculata and 46 other capillariid isolates available from the GenBank demonstrated a sister-taxon relationship between our specimens and the type species of Baruscapillaria. But, at the same time, significant genetic distances between both taxa showed an interesting variability of the genus Baruscapillaria. The probable division of this genus into multiple genera could probably be confirmed through integrative studies including more species.


Assuntos
Doenças das Aves/parasitologia , Aves/parasitologia , Nematoides/classificação , Infecções por Nematoides/veterinária , Animais , Argentina , DNA de Helmintos/genética , Feminino , Variação Genética , Masculino , Nematoides/citologia , Nematoides/genética , Infecções por Nematoides/parasitologia , Filogenia , RNA Ribossômico 18S/genética
10.
Parasitol Int ; 82: 102302, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33607282

RESUMO

Surveys on parasites of bats from the Americas have been conducted, but information on helminths is still scarce, especially in the Neotropical region. In Mexico, there are species of bats that lack of a record for helminth species, such as members of the family Noctilionidae. The present study describes for the first time the helminths of Noctilio leporinus in Campeche, Mexico. In 2017, six specimens of N. leporinus were studied for helminths. The species identification of helminths was based on morphological studies and molecular analysis of fragments of the 28S rDNA. All bat specimens were infected for at least one helminth species. Three helminth taxa were identified: the trematode Pygidiopsis macrostomum, and the nematodes Tricholeiperia cf. proencai, and Heligmonellidae gen. sp. The morphological identification of P. macrostomum was confirmed by sequence analysis of 28S rDNA gene. The phylogeny of P. macrostomum grouped our sequence with other sequences of the same species collected in Brazil. The phylogenetic tree of Heligmonellidae gen. sp. indicated that the helminth belongs to clade formed by the species Odilia bainae, Nippostrongylus magnus and Nippostrongylus brasiliensis of the family Heligmonellidae. The phylogenetic analysis of the 28S sequences of T. cf. proencai did not show any similarity or close affinity with nematodes from which that gene has been sequenced to date. The findings of the present study increase the number of helminth species parasitizing bats in Mexico.


Assuntos
Quirópteros , Nematoides/isolamento & purificação , Infecções por Nematoides/veterinária , Trematódeos/isolamento & purificação , Infecções por Trematódeos/veterinária , Animais , DNA de Helmintos/análise , Feminino , Masculino , México/epidemiologia , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Prevalência , RNA Ribossômico 28S/análise , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
11.
Vet Parasitol ; 290: 109362, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33524780

RESUMO

Nematicide combinations may be a valid strategy to achieve effective nematode control in the presence of drug resistance. The goal of the current trial was to evaluate the pharmaco-parasitological performance of the moxidectin (MOX) and levamisole (LEV) combination after four years of continuous use in lambs naturally parasitized with multi-resistant gastrointestinal nematodes. At the beginning of the trial, 40 lambs were divided into four groups (n = 10), which were untreated (control) or subcutaneously treated with MOX (0.2 mg/kg), LEV (8 mg/kg) or with the combination MOX + LEV (administered separately at 0.2 and 8 mg/kg, respectively). Blood samples were collected at different times post-treatment and LEV and MOX plasma concentrations were measured by HPLC. The clinical efficacy of the continuous use of MOX + LEV combination was assessed with the controlled efficacy test (CET), performed at the beginning and end of the study, and with the faecal egg count reduction (FECR) test, performed over the four-year study period. No significant adverse pharmacokinetic changes were observed either for MOX or LEV after their co-administration to infected lambs. The CET (first year) showed efficacies of 84.3 % (Haemonchus contortus), 100 % (Teladorsagia circumcincta and Trichostrongylus axei), and 97.4 % (T. colubriformis). After the repetitive use of the combined treatment for four years, those efficacies remained high (100 %) and only decreased to 58 % against T. colubriformis. The evaluation of the FECR over the study period showed fluctuations in the performance of the combined administration. The initial FECR (2014) was 99 % (MOX), 85 % (LEV) and 100 % (MOX + LEV). The co-administration of MOX + LEV during the four-year experimental period resulted in a significantly higher anthelmintic effect (87 %) than that of MOX (42 %) or LEV (69 %) given alone. The combined use of MOX + LEV to control resistant gastrointestinal nematodes appears to be a valid strategy under specific management conditions. A high initial therapeutic response to the combination would be a relevant feature for the success of this tool.


Assuntos
Levamisol/uso terapêutico , Macrolídeos/uso terapêutico , Nematoides/efeitos dos fármacos , Infecções por Nematoides/veterinária , Doenças dos Ovinos/tratamento farmacológico , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/uso terapêutico , Área Sob a Curva , Esquema de Medicação , Combinação de Medicamentos , Resistência a Múltiplos Medicamentos , Feminino , Meia-Vida , Levamisol/administração & dosagem , Levamisol/farmacocinética , Macrolídeos/administração & dosagem , Macrolídeos/farmacocinética , Masculino , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Ovinos , Doenças dos Ovinos/parasitologia
12.
Animal ; 15(4): 100176, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33637437

RESUMO

Given the economic impact of gastrointestinal nematode infection on livestock farming worldwide, and increasing anthelmintic resistance, it is imperative to develop practical, efficient and sustainable control strategies. Targeted selective treatment (TST), whereby anthelmintic treatments are administered to animals individually, based on selection criteria such as weight gain, has been shown to successfully maintain animal productivity whilst reducing the selection pressure for anthelmintic resistance and the economic cost of treatment in experimental and commercial settings. Despite the benefits of the TST approach, the equipment and time required to monitor animals individually make this strategy unsuitable for some farming enterprises. The sentinel group approach aims to maintain the benefits observed using TST whilst reducing these requirements. The study involved two experiments, each following a group of 80 lambs through their first grazing season. Anthelmintic treatment of the whole group was determined by monitoring the weight gain of identified sentinel lambs within it every 2 weeks: when 40% of the sentinel lambs failed to reach their weight gain targets, the whole group was treated. The sentinel lambs consisted of 45% of the group (n = 36) in experiment one and 20% (n = 16) in experiment two. A control group of 20 lambs was co-grazed with the main group during both experiments; in experiment one, the sentinel approach was compared with a TST approach, in which control lambs were treated on an individual basis in response to weight gain. In experiment two, the sentinel approach was compared with conventional prophylaxis, where all lambs in the control group were treated at strategic time points throughout the season (= strategic prophylactic treatment). The sentinel lambs were found to be representative of overall group performance regardless of the proportion of sentinels within the group: they recorded similar growth rates and reached weight gain targets simultaneously at each time point and overall. Live-weight gain was also similar between sentinel and control animals in both experiments. The findings of the current study suggest that monitoring sentinel lambs comprising 20% of a group of grazing lambs is sufficient to determine the need for anthelmintic treatment within the whole group, and that this approach maintains production in line with conventional or TST treatment regimes.


Assuntos
Anti-Helmínticos , Nematoides , Infecções por Nematoides , Doenças dos Ovinos , Animais , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Fezes , Infecções por Nematoides/veterinária , Contagem de Ovos de Parasitas/veterinária , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/prevenção & controle
13.
Acta Vet Scand ; 63(1): 5, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33494770

RESUMO

BACKGROUND: With intensive use of anthelmintic drugs in recent decades, anthelmintic resistance (AR) in horse nematodes is becoming a growing issue in many countries. However, there is little available information about the parasites, treatment practices or AR in the horse population in Lithuania. The aim of this study was to assess the current situation of AR on horse farms in Lithuania. The study was conducted in 25 stables on horses with a strongyle faecal egg count (FEC) of ≥ 200 eggs per gram. A faecal egg count reduction test (FECRT) was performed on each farm after administration of ivermectin (IVM) or pyrantel (PYR). RESULTS: The efficacy of IVM was comparatively high, with 98.8% of 250 horses having a zero egg count 14 days after treatment. Two conditions were used to interpret the FECRT results for PYR: firstly, resistance was determined when FECR was < 90% and the lower 95% confidence interval (LCL) was < 80%, and secondly when in addition the upper confidence level (UCL) was < 95%. Under the first condition, resistance against PYR was found in five stables (25% of all tested herds), while when considering the UCL as well, resistance was only detected in two stables (8%). The FEC showed a significant (P < 0.01) difference between the treatment and control groups. Only cyathostomin larvae were detected in larval cultures derived from strongyle-positive faecal samples collected 14 days after treatment of a test group with PYR. CONCLUSIONS: This in vivo study showed that PYR resistance is prevalent on horse farms in Lithuania, while the efficacy of IVM still appears to be unaffected. However, further studies of ivermectin resistance are needed. These findings should guide the implementation of more sustainable management of strongyle infections in horses in Lithuania.


Assuntos
Anti-Helmínticos/uso terapêutico , Doenças dos Cavalos/tratamento farmacológico , Infecções por Nematoides/veterinária , Animais , Anti-Helmínticos/farmacologia , Resistência a Medicamentos , Fezes/parasitologia , Feminino , Doenças dos Cavalos/parasitologia , Cavalos , Ivermectina/farmacologia , Ivermectina/uso terapêutico , Lituânia , Masculino , Nematoides/efeitos dos fármacos , Infecções por Nematoides/tratamento farmacológico , Contagem de Ovos de Parasitas/veterinária , Pirantel/farmacologia , Pirantel/uso terapêutico
14.
Vet J ; 268: 105602, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33468301

RESUMO

Gastrointestinal nematodes (GIN) are a cause of significant losses in animal production worldwide. In recent years, there have been important advances in the biological control of GIN of ruminants and horses. While these measures are still relatively under-utilised in practice, interest will undoubtedly grow due to the emergence of drug resistant parasite populations, the rise in demand for organically farmed products (which does not allow prophylactic use of drugs, including anthelmintics) and legislation, which regulates and restricts the use of anthelmintics. This review provides an overview of the most promising biocontrol agents of GIN of grazing animals including nematophagous fungi, dung beetles, earthworms, predacious nematodes and nematophagous mites. Recent advancements in these fields are evaluated, and the potential reasons for the delayed development and slow uptake of biocontrol agents are discussed. It is now widely believed that no method of GIN control is sustainable alone, and a combination of strategies (i.e. integrated pest management) is required for long term, effective parasite control. This review shows that, although their efficacies are lower than those of conventional anthelmintics, biological control agents are an important adjunct to traditional GIN control.


Assuntos
Agentes de Controle Biológico/farmacologia , Gastroenteropatias/veterinária , Infecções por Nematoides/veterinária , Controle Biológico de Vetores/métodos , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/prevenção & controle , Gastroenteropatias/parasitologia , Gastroenteropatias/prevenção & controle , Doenças das Cabras/parasitologia , Doenças das Cabras/prevenção & controle , Cabras , Doenças dos Cavalos/parasitologia , Doenças dos Cavalos/prevenção & controle , Cavalos , Infecções por Nematoides/parasitologia , Infecções por Nematoides/prevenção & controle , Ovinos , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/prevenção & controle , Carneiro Doméstico
15.
Parasitol Res ; 120(3): 963-970, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33501587

RESUMO

Capillariidae is a group of nematode parasites of vertebrates with a complex taxonomy. The structure of the eggshell, which was indicated as the most important characteristic for identification of genus or species through eggs, is very diverse among genera. The visualization and characterization of eggshell by light microscopy (LM) are a challenging task since different planes of the egg surface are needed. Nevertheless, categories of eggshell ornamentation were proposed by LM: smooth, punctuated, reticulated type I, and reticulated type II. The present study aimed to characterize the eggshell structure of Capillariidae species, parasites of mammals and avians, deposited in a helminthological collection using scanning electron microscopy (SEM). Institutional Biological Collections are taxonomic repositories of specimens described and strictly identified at the species level by systematics specialists. SEM eggshell images were obtained from 12 species belonging to 5 genera (Aonchotheca, Baruscapillaria, Capillaria, Echinocoleus, Eucoleus) and compared to their respective LM images. Eggshell patterns observed using SEM were associated categories of eggshell ornamentation previously proposed by LM images. The SEM data indicate that eggshell categories are not in agreement with capillariid genera or sites of infection. However, the study provides previously unknown SEM eggshell information from curated species, which contributes with a specific and supplementary taxonomic feature at the species level of Capillariidae.


Assuntos
Nematoides/ultraestrutura , Infecções por Nematoides/veterinária , Óvulo/ultraestrutura , Animais , Aves/parasitologia , Mamíferos/parasitologia , Microscopia Eletrônica de Varredura , Nematoides/classificação , Infecções por Nematoides/parasitologia , Especificidade da Espécie
16.
BMC Vet Res ; 17(1): 19, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413368

RESUMO

BACKGROUND: Helminthic infections, in particular those caused by gastrointestinal nematodes (GIN), are found worldwide and are among the most economically important diseases of goats. Anthelmintic resistance (AR) in GIN of goats is currently present worldwide, and single- or multidrug resistant species are widespread. The aim of this study was to determine the prevalence of AR to benzimidazoles (BZ), macrocyclic lactones (ML) and imidazothiazoles represented by levamisole (LEV) in the Polish goat herds by using an in vitro larval development test, which is useful especially in large-scale epidemiological surveys. RESULTS: This cross-sectional study was conducted from September 2018 to June 2019 and enrolled 42 dairy goat herds scattered over the entire country. The most commonly used anthelmintic class in goat herds in Poland were BZ (92%), followed by ML (85%) and LEV (13%). BZ-resistant GIN populations were found in 37 herds (88%, CI 95%: 75 to 95%), ML-resistant GIN populations in 40 herds (95%, CI 95, 84 to 99%), and LEV-resistant GIN populations in 5 herds (12%, CI 95%: 5 to 25%). Multidrug resistance involving all three anthelmintic classes was found in 5 herds (12%, CI 95, 5 to 25%). Based on the morphological features of stage 3 larvae the main resistant GIN turned out to be Haemonchus contortus and Trichostrongylus spp. The use of BZ and frequency of anthelmintic treatments were significantly related to the presence of AR to BZ in Polish goat herds. CONCLUSIONS: This cross-sectional study demonstrates the existence of AR to BZ, ML and LEV on Polish goat farms. Resistance to BZ and ML is widespread, while AR to LEV is currently at a low level. A considerable proportion of herds harbours multidrug resistant GIN, which requires further consideration. An effective anthelmintic treatment strategy, reasonable preventive measures and better understanding of the resistance-related management practices by farmers and veterinarians may delay further development of AR.


Assuntos
Anti-Helmínticos/farmacologia , Resistência a Medicamentos , Doenças das Cabras/parasitologia , Nematoides/efeitos dos fármacos , Animais , Estudos Transversais , Doenças das Cabras/tratamento farmacológico , Cabras , Haemonchus/efeitos dos fármacos , Haemonchus/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Nematoides/crescimento & desenvolvimento , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/veterinária , Polônia , Prevalência , Trichostrongylus/efeitos dos fármacos , Trichostrongylus/crescimento & desenvolvimento
17.
Parasitol Res ; 120(3): 1137-1141, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33103217

RESUMO

Pulmonary capillariasis is a parasitic disease caused by the nematode Eucoleus aerophilus which affects wild and domestic carnivores. Currently, there are no anthelmintics approved for use in the treatment of dogs infected with E. aerophilus. The use of several anthelmintics has been reported in a few case reports and field efficacy studies in cats; much less is known on the treatment of dogs infected with E. aerophilus. The paper describes a case of a 4-month-old, mixed breed intact male referred to the Veterinary Teaching Hospital (VTH) of the Department of Veterinary Medical Science of the University of Bologna for a routine vaccination and tested positive for E. aerophilus. The dog has not been responding to three different administered treatments, such as moxidectin, fenbendazole, and milbemycin oxime. Eighteen months after the first fecal examination, owner has brought in the dog for a routine visit; a coprological examination was requested and performed resulting negative for parasites. Veterinary practitioners, parasitologists, diagnostic laboratories, and dog owners need to be aware of the increased danger of possible treatment failure when attempting to control parasitic infections for which there are no approved anthelmintics with established efficacies available for use.


Assuntos
Antinematódeos/uso terapêutico , Doenças do Cão/tratamento farmacológico , Nematoides/classificação , Infecções por Nematoides/veterinária , Animais , Antinematódeos/farmacologia , Doenças do Cão/parasitologia , Cães , Fezes/parasitologia , Fenbendazol/farmacologia , Fenbendazol/uso terapêutico , Macrolídeos/farmacologia , Macrolídeos/uso terapêutico , Masculino , Nematoides/efeitos dos fármacos , Nematoides/isolamento & purificação , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Falha de Tratamento
18.
Vet Parasitol ; 289: 109317, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33246235

RESUMO

Parasitic diseases caused by gastrointestinal nematodes (GIN) are responsible for a major impact on ruminant welfare. Although the available anthelmintics have a safe margin of toxicity to the animals, their indiscriminate use has increased the selection of resistant parasite populations. In this scenario, essential oils (EO) stand out as a promising ecofriendly therapeutic alternative against GIN. The objective of this work was to determine the effect of the EO of Mentha villosa Hubs (MVEO) collected in 2017 and 2018, M. x piperita (MPEO) and their main components, carvone and limonene, against the third stage larvae (L3) of Haemonchus spp. and Trichostrongylus spp. The solutions, including in nanoemulsion preparations, were tested in a range of concentrations using the larval migration inhibition test (LMIT). The EO and carvone were also tested in combination with nitroxynil (NTX) to determine their effect as drug enhancers (additive or synergy). MVEO/2017, MVEO/2018, MPEO and carvone showed 70.6 (73.4 mg/mL), 86.3 (74.9 mL/mL), 95.5 (143.6 mg/mL), and 88.2 % (38.3 mg/mL) efficacy against L3, respectively. Carvone alone had approximately a 3-fold higher efficacy when compared to its concentration in each EO: 68.8 % in MVEO/2017 and 83.9 % in MVEO/2018. Limonene did not show any significant effect on inhibiting L3 migration. The combination of MPEO and NTX, and carvone and NTX showed a statistically significantly (P <  0.05) synergic and additive effect, respectively, when compared to the isolated treatment. The nanoemulsion of MVEO/2017 at 0.367 mg/mL, inhibited L3 migration by 83.1 %, demonstrating to be highly effective (concentration ratio of 1:0.004), when compared to the MVEO/2017 (70.6 % at 73.4 mg/mL) extraction. The in vitro data from the combination of MPEO or carvone plus NTX suggest that these products can be considered for in vivo experiments against the most important GIN of ruminants as drug enhancers, possibly reducing the final concentration of NTX`. The efficacy of carvone was higher (EC50 = 1.96 mg/mL) than its expected efficacy, based on its concentrations on both EO. Therefore, this component does not need the entire EO composition to exert its L3 motility action. The remarkable efficacy demonstrated by the MVEO/2017/nanoemulsion (EC50 = 0.10 mg/mL), supports its potential to be a candidate to the next-generation therapy to alleviate clinical parasite infections and combat GIN resistant populations.


Assuntos
Anti-Helmínticos/farmacologia , Mentha/química , Nematoides/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Óleos Vegetais/farmacologia , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/química , Monoterpenos Cicloexânicos/administração & dosagem , Monoterpenos Cicloexânicos/química , Monoterpenos Cicloexânicos/farmacologia , Sinergismo Farmacológico , Quimioterapia Combinada , Limoneno/administração & dosagem , Limoneno/química , Limoneno/farmacologia , Infecções por Nematoides/parasitologia , Infecções por Nematoides/veterinária , Nitroxinila/administração & dosagem , Nitroxinila/química , Nitroxinila/farmacologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Compostos Fitoquímicos/química , Óleos Vegetais/química , Ovinos , Doenças dos Ovinos/parasitologia
19.
Vet Parasitol ; 289: 109339, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33359968

RESUMO

Our current understanding of differences in the epidemiology of gastrointestinal nematode (GIN) species in co-grazed sheep and goats is inadequate with reference to the development of sustainable control strategies. The next-generation metabarcoding sequencing method referred to as the 'nemabiome' allows some of these differences to be explored to describe the intensity of co-infecting GIN species. We applied this platform to study sheep and goats that were co-grazed on Guinea grass pasture in northeastern Brazil. Co-grazed goats and sheep were treated with a monepantel anthelmintic, then exposed to the same gastrointestinal nematode species. Overall, there were differences in the prevalence of GIN species identified in the sheep and goats; Trichostrongylus colubriformis and Teladorsagia circumcincta predominated in goat kids, while Haemonchus contortus predominated in adult does, ewes and lambs once burdens became re-established after anthelmintic treatment. Description of the pattern of re-infection following anthelmintic treatment was prevented by the unpredicted poor efficacy of 2.5 mg/kg and 5 mg/kg, respectively, of monepantel against O. columbianum and T. circumcincta in lambs, and T. circumcincta adult does. Differences in drug efficacy between host age and species groups may be important when considering sustainable GIN control strategies for co-grazed animals. The aggregated FECs of the adult does and goat kids representing re-established GIN burdens, were higher than those of the co-grazed adult ewes and lambs. This implies that there are inherent differences in GIN species adaptation to the two naïve small ruminant host species, and shows the need for better understanding of the factors giving rise to this situation associated with exposure to infective larvae and host responses. At the start of the study, the adult does were co-infected with several GIN species, with the highest intensity of T. circumcincta, contrasting with the situation in the adult ewes, in which H. contortus predominated. However, once burdens became re-established after treatment, H. contortus predominated in both adult does and ewes. This demonstrates the potential for host burdens of H. contortus to establish and predominate after anthelmintic treatment when burdens of co-infecting GIN species are low.


Assuntos
Código de Barras de DNA Taxonômico , Doenças das Cabras/parasitologia , Nematoides/genética , Infecções por Nematoides/veterinária , Doenças dos Ovinos/parasitologia , Aminoacetonitrila/análogos & derivados , Aminoacetonitrila/uso terapêutico , Animais , Anti-Helmínticos/uso terapêutico , Fezes/parasitologia , Feminino , Genômica , Cabras , Masculino , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas , Reação em Cadeia da Polimerase , Ovinos
20.
Parasite ; 27: 69, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33277891

RESUMO

Helminth infections are ubiquitous in grazing ruminant production systems, and are responsible for significant costs and production losses. Anthelmintic Resistance (AR) in parasites is now widespread throughout Europe, although there are still gaps in our knowledge in some regions and countries. AR is a major threat to the sustainability of modern ruminant livestock production, resulting in reduced productivity, compromised animal health and welfare, and increased greenhouse gas emissions through increased parasitism and farm inputs. A better understanding of the extent of AR in Europe is needed to develop and advocate more sustainable parasite control approaches. A database of European published and unpublished AR research on gastrointestinal nematodes (GIN) and liver fluke (Fasciola hepatica) was collated by members of the European COST Action "COMBAR" (Combatting Anthelmintic Resistance in Ruminants), and combined with data from a previous systematic review of AR in GIN. A total of 197 publications on AR in GIN were available for analysis, representing 535 studies in 22 countries and spanning the period 1980-2020. Reports of AR were present throughout the European continent and some reports indicated high within-country prevalence. Heuristic sample size-weighted estimates of European AR prevalence over the whole study period, stratified by anthelmintic class, varied between 0 and 48%. Estimated regional (country) prevalence was highly heterogeneous, ranging between 0% and 100% depending on livestock sector and anthelmintic class, and generally increased with increasing research effort in a country. In the few countries with adequate longitudinal data, there was a tendency towards increasing AR over time for all anthelmintic classes in GIN: aggregated results in sheep and goats since 2010 reveal an average prevalence of resistance to benzimidazoles (BZ) of 86%, macrocyclic lactones except moxidectin (ML) 52%, levamisole (LEV) 48%, and moxidectin (MOX) 21%. All major GIN genera survived treatment in various studies. In cattle, prevalence of AR varied between anthelmintic classes from 0-100% (BZ and ML), 0-17% (LEV) and 0-73% (MOX), and both Cooperia and Ostertagia survived treatment. Suspected AR in F. hepatica was reported in 21 studies spanning 6 countries. For GIN and particularly F. hepatica, there was a bias towards preferential sampling of individual farms with suspected AR, and research effort was biased towards Western Europe and particularly the United Kingdom. Ongoing capture of future results in the live database, efforts to avoid bias in farm recruitment, more accurate tests for AR, and stronger appreciation of the importance of AR among the agricultural industry and policy makers, will support more sophisticated analyses of factors contributing to AR and effective strategies to slow its spread.


Assuntos
Anti-Helmínticos , Resistência a Medicamentos , Gado , Nematoides , Infecções por Nematoides , Animais , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Bovinos , Europa (Continente)/epidemiologia , Cabras , Gado/parasitologia , Nematoides/efeitos dos fármacos , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Infecções por Nematoides/veterinária , Doenças Parasitárias em Animais/tratamento farmacológico , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/parasitologia , Ovinos
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