Control trial and fecal egg count reduction test determinations of nematocidal efficacies of moxidectin and generic ivermectin in recently weaned, naturally infected calves

Yazwinski, T. A.; Tucker, Chris; Wray, E.; Jones, L.; Reynolds, J. L.; Hornsby, P.; Powell, J. G.

doi:10.1016/j.vetpar.2012.12.061

Cited by 23 publications

(11 citation statements)

References 23 publications

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“…and strongylida excretion were previously observed in cattle (31). In some studies, species belonging to the Nematodirus genus appeared to be dose-limiting for these drugs (4,37); therefore, eprinomectin in goat at the dose used probably lacked persistent efficacy against the species belonging to this genus.…”

Section: Discussionmentioning

confidence: 89%

Gastrointestinal nematodes of goats: host–parasite relationship differences in breeds at summer mountain pasture in northern Italy

Zanzani

Gazzonis

Olivieri

et al. 2019

Journal of Veterinary Research

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IntroductionThe Orobic goat is a hardy breed native to the Orobic Alps (Lombardy, northern Italy). The aim of the study was the assessment of gastrointestinal nematode (GIN) egg excretion in Alpine and Saanen (cosmopolite breeds) and Orobic grazing goats, after a strategic treatment with eprinomectin in late June.Material and MethodsIndividual faecal samples from a mixed flock of cosmopolite and Orobic goats were collected and analysed by the FLOTAC double technique every three weeks from June to September.ResultsStrongylida was the primary GIN infection observed in goats that grazed on Alpine pastures; a strategic treatment with eprinomectin led to a prolonged reduction of egg excretion during the whole study period. Egg excretion was also influenced by breed. Pluriparous Orobic does were able to control reinfection better than the pluriparous cosmopolite does. Regarding Nematodirus sp. eggs per gram of faeces (EPG), the autochthonous Orobic breed presented higher values than the cosmopolite breeds. However, cosmopolite goats presented higher EPG values of Strongyloides papillosus than their Orobic counterparts in August.ConclusionsFurther studies on genetic features of local autochthonous goats, such as the Orobic breed, are needed, since they could reveal peculiar characteristics of susceptibility, resistance or resilience to GIN infection, providing genetic resources for selection.

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Section: Discussionmentioning

confidence: 89%

Gastrointestinal nematodes of goats: host–parasite relationship differences in breeds at summer mountain pasture in northern Italy

Zanzani

Gazzonis

Olivieri

et al. 2019

Journal of Veterinary Research

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“…Additionally, there have been few studies of benzimidazole resistance in the closely related parasite, H. placei , hence little is known about the genetics of benzimidazole resistance in this species. However, it was considered likely that resistance would be at an earlier stage of emergence in H. placei than in H. contortus due to the lower amount of benzimidazole use in cattle than in sheep and the lack of clinical reports of poor treatment efficacy (Yazwinski TA1, 2013). The focus of this work was to investigate the molecular genetics of the known benzimidazole resistance mutations in H. contortus and H. placei of the large ruminants in the Punjab province of Pakistan.…”

Section: Discussionmentioning

confidence: 99%

Emergence and the spread of the F200Y benzimidazole resistance mutation in Haemonchus contortus and Haemonchus placei from buffalo and cattle

Ali¹,

Rashid²,

Shabbir

et al. 2018

Preprint

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9Benzimidazoles have been intensively used in the livestock sector, particularly in small 3 0 ruminants for over 40 years. This has been led to the widespread emergence of resistance in a 3 1 number of small ruminant parasite species, in particular Haemonchus contortus. In many 3 2 counties benzimidazole resistance in the small ruminants H. contortus has become severely 3 3 compromising its control; but there is a little information on benzimidazole resistance in H. 3 4 contortus infecting buffalo and cattle. Resistance to benzimidazoles have also been reported 3 5 in the large ruminant parasite, Haemonchus placei, but again there is relatively little 3 6 information on its prevalence. Hence it is extremely important to understand how resistance-3 7 conferring mutations emerge and spread in both parasites in the buffalo and cattle host in 3 8 order to develop the approaches for the recognition of the problem at an early stage of its 3 9 development. The present study suggests that the F200Y (TAC) mutation is common in H. 4 0 contortus, being detected in 5/7 populations at frequencies between 7 to 57%. Furthermore, 4 1 6/10 H. placei populations contained the F200Y (TAC) mutation, albeit at low frequencies of 4 2 between 0.4 to 5%. The phylogenetic analysis suggests that the F200Y (TAC) mutation in H. 4 3 contortus has emerged on multiple occasions in the region, with at least three independent 4 4 emergence of resistance alleles across the populations. In contrast, the F200Y (TAC) 4 5 resistance-conferring mutation in H. placei is only seen on a single haplotype. A high level of 4 6 haplotype frequency of the susceptible alleles in the region, suggests that the unique 4 7 resistance conferring-mutation has spread from a single emergence; likely by anthropogenic 4 8 animal movement. Overall, these results provide the first clear genetic evidence for the 4 9Recently, we have developed and validated the Illumina Mi-seq deep amplicon sequencing

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“…Currently faecal egg count reduction tests (FECRT) are used to assess this, however this technique has only been validated for sheep and not cattle nematodes (Sutherland and Bullen, 2014). Compared with sheep nematodes, O. ostertagi tends to show less aggregation between hosts, excrete fewer eggs (Demeler et al., 2010, El-abdellati et al., 2010, Yazwinski et al., 2013) and FEC are generally less reflective of WB as a result of density-dependent effects on parasite fecundity (Michel et al., 1978, Smith et al., 1987). As a result, the limited numbers of studies conducted on cattle TST have focused on performance and total number of anthelmintic applications.…”

Section: Discussionmentioning

confidence: 99%

Modelling the consequences of targeted selective treatment strategies on performance and emergence of anthelmintic resistance amongst grazing calves

Berk

Laurenson

Forbes

et al. 2016

International Journal for Parasitology: Drugs and Drug Resistan

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The development of anthelmintic resistance by helminths can be slowed by maintaining refugia on pasture or in untreated hosts. Targeted selective treatments (TST) may achieve this through the treatment only of individuals that would benefit most from anthelmintic, according to certain criteria. However TST consequences on cattle are uncertain, mainly due to difficulties of comparison between alternative strategies. We developed a mathematical model to compare: 1) the most ‘beneficial’ indicator for treatment selection and 2) the method of selection of calves exposed to Ostertagia ostertagi, i.e. treating a fixed percentage of the population with the lowest (or highest) indicator values versus treating individuals who exceed (or are below) a given indicator threshold. The indicators evaluated were average daily gain (ADG), faecal egg counts (FEC), plasma pepsinogen, combined FEC and plasma pepsinogen, versus random selection of individuals. Treatment success was assessed in terms of benefit per R (BPR), the ratio of average benefit in weight gain to change in frequency of resistance alleles R (relative to an untreated population). The optimal indicator in terms of BPR for fixed percentages of calves treated was plasma pepsinogen and the worst ADG; in the latter case treatment was applied to some individuals who were not in need of treatment. The reverse was found when calves were treated according to threshold criteria, with ADG being the best target indicator for treatment. This was also the most beneficial strategy overall, with a significantly higher BPR value than any other strategy, but its degree of success depended on the chosen threshold of the indicator. The study shows strong support for TST, with all strategies showing improvements on calves treated selectively, compared with whole-herd treatment at 3, 8, 13 weeks post-turnout. The developed model appeared capable of assessing the consequences of other TST strategies on calf populations.

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Control trial and fecal egg count reduction test determinations of nematocidal efficacies of moxidectin and generic ivermectin in recently weaned, naturally infected calves

Cited by 23 publications

References 23 publications

Gastrointestinal nematodes of goats: host–parasite relationship differences in breeds at summer mountain pasture in northern Italy

Gastrointestinal nematodes of goats: host–parasite relationship differences in breeds at summer mountain pasture in northern Italy

Emergence and the spread of the F200Y benzimidazole resistance mutation in Haemonchus contortus and Haemonchus placei from buffalo and cattle

Modelling the consequences of targeted selective treatment strategies on performance and emergence of anthelmintic resistance amongst grazing calves

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