Faecal Reduction Research Articles

Effectiveness of Anthelmintic Treatments in Small Ruminants in Germany.

Simple SummaryParasitic worms are a major threat to the health and production of sheep and goats worldwide, particularly because many worms have become resistant to commonly applied drugs. This problem is well known around the world, but the situation is currently not well studied in Germany. This study was therefore performed to evaluate the effectiveness of treatments against infection with gastrointestinal nematodes. Faecal samples from animal groups were examined before and after treatment, the worm eggs in the feaces were counted, and the reduction in egg excretion following treatment was calculated. Eggs of Haemonchus contortus (barber’s pole worm) were stained to differentiate them from other gastrointestinal nematodes. Treatments were chosen and carried out by farmers together with their local veterinarian. Additional information was collected by questionnaires to check if the treatments were performed correctly. Reduced effectiveness was observed for all available drugs, but some showed better treatment success than others. The barber’s pole worm frequently survived treatments by most products. The high percentage of treatment failures is highly concerning, and it is necessary to develop and/or apply alternative methods of worm control to prevent the deterioration of this situation.Widespread anthelmintic resistance is a concern for small ruminant health and production worldwide. The current situation regarding anthelmintic efficacy is, however, not very well studied in Germany. Thus, a nationwide field study was undertaken to assess the effectiveness of 253 treatments performed in 223 small ruminant flocks by faecal egg count reduction test (FECRT) using pooled samples and a modified McMaster method. The percentage of Haemonchus contortus and non-Haemonchus eggs was determined by fluorescence microscopy following peanut agglutinin–fluorescein isothiocyanate staining. Treatments were chosen and performed by farmers together with their local veterinarian, and potentially confounding factors for FECRT results were addressed as far as possible by rigorous inclusion criteria. Reduced effectiveness was observed for treatments with all examined anthelmintic classes, but treatments with benzimidazoles and moxidectin showed significantly poorer results than monepantel, a closantel and mebendazole combination, and levamisole. Low case numbers precluded reliable assessment of avermectins. Unsuccessful treatments were frequently associated with the survival of H. contortus, but this was also observed for non-Haemonchus genera. The results are highly concerning, and sustainable approaches to parasite control are urgently needed to prevent further deterioration of this situation.

Reduction of the nematode egg reappearance period in horses after anthelmintic therapy.

Background and Aim:Anthelmintics are used to control equine nematodes. However, helminth resistance to regularly used drugs is a well-known challenge. Among tests to assess effective control and monitor resistance, the most common is the fecal egg count reduction test (FECRT). In the absence of reliable FECRT results, the nematode egg reappearance period (ERP) is taken into account. This study aimed to examine horses from farms around the Moscow Region to assess nematode resistance through ERP after therapy.Materials and Methods:In the first stage, fecal samples from 280 horses were examined by the flotation method with a sodium nitrate solution. The eggs per gram (EPG) in feces were counted using the modified McMaster technique. One hundred and forty out of 280 horses were selected for further work. Five groups were formed: Two groups of horses infected with strongyles (n = 50) and three groups with Parascaris equorum (n = 90). Therapy against strongyles was performed with albendazole and ivermectin. Therapy for parascaridosis was performed with fenbendazole, ivermectin, and aversectin C. Samples from the horses in each group were taken on the 14th day (2 weeks), 28th day (4 weeks), 42nd day (6 weeks), 56th day (8 weeks), and 84th day (12 weeks) after treatment, and the amount of EPG in each sample was determined.Results:Overall, nematodes were found in 65% of the horses examined. P. equorum was most frequently recorded (42.1%) followed by Strongylidae gen. spp. (27.9%). The strongyles ERP after therapy with albendazole and ivermectin was estimated on 42 days (6 weeks). The growth of P. equorum eggs in the feces was observed from the 56th day (8 weeks) after therapy with fenbendazole, from the 42nd day (6 weeks) after therapy with ivermectin, and was observed from the 84th day (12 weeks) after the use of aversectin.Conclusion:Our study shows widespread reductions in nematode ERPs across the Moscow Region after ivermectin therapy in horses, suggesting that additional monitoring of these farms is needed for effective control of anthelmintic resistance.

Comparison of FECPAKG2, a modified Mini-FLOTAC technique and combined sedimentation and flotation for the coproscopic examination of helminth eggs in horses

BackgroundDue to high prevalence of anthelmintic resistance in equine helminths, selective treatment is increasingly promoted and in some countries a positive infection diagnosis is mandatory before treatment. Selective treatment is typically recommended when the number of worm eggs per gram faeces (epg) exceeds a particular threshold. In the present study we compared the semi-quantitative sedimentation/flotation method with the quantitative methods Mini-FLOTAC and FECPAKG2 in terms of precision, sensitivity, inter-rater reliability and correlation of worm egg counts to improve the choice of optimal diagnostic tools.MethodsUsing sedimentation/flotation (counting raw egg numbers up to 200), we investigated 1067 horse faecal samples using a modified Mini-FLOTAC approach (multiplication factor of 5 to calculate epgs from raw egg counts) and FECPAKG2 (multiplication factor of 45).ResultsFive independent analyses of the same faecal sample with all three methods revealed that variance was highest for the sedimentation/flotation method while there were no significant differences between methods regarding the coefficient of variance. Sedimentation/flotation detected the highest number of samples positive for strongyle and Parascaris spp. eggs, followed by Mini-FLOTAC and FECPAKG2. Regarding Anoplocephalidae, no significant difference in frequency of positive samples was observed between Mini-FLOTAC and sedimentation/flotation. Cohen’s κ values comparing individual methods with the combined result of all three methods revealed almost perfect agreement (κ ≥ 0.94) for sedimentation/flotation and strong agreement for Mini-FLOTAC (κ ≥ 0.83) for strongyles and Parascaris spp. For FECPAKG2, moderate and weak agreements were found for the detection of strongyle (κ = 0.62) and Parascaris (κ = 0.51) eggs, respectively. Despite higher sensitivity, the Mini-FLOTAC mean epg was significantly lower than that with FECPAKG2 due to samples with > 200 raw egg counts by sedimentation/flotation, while in samples with lower egg shedding epgs were higher with Mini-FLOTAC than with FECPAKG2.ConclusionsFor the simple detection of parasite eggs, for example, to treat foals infected with Parascaris spp., sedimentation/flotation is sufficient and more sensitive than the other two quantitative investigared in this study. Mini-FLOTAC is predicted to deliver more precise results in faecal egg count reduction tests due to higher raw egg counts. Finally, to identify animals with a strongyle epg above a certain threshold for treatment, FECPAKG2 delivered results comparable to Mini-FLOTAC.Grpahical

Effects of Vernonia amygdalina methanol leaf extract and fractions on Ascaridia galli in experimentally infected birds with regard to its pathological effect

BackgroundHelminthiasis, usually a chronic problem in poultry, is the major cause of economic losses in the poultry industry. This study was undertaken with the aim of evaluating the in vitro and in vivo anthelmintic effects of Vernonia amygdalina methanol leaf extract and fractions on Ascaridia galli in experimentally infected birds. Standard protocols for extraction, phytochemical screening, isolation and infection of parasite and histological examination were followed.ResultAt 50 mg/ml albendazole (ALB) caused the highest inhibition of embryonation (97.3%) followed by crude methanol extract (CME) (94.5%), ethyl acetate fraction (EAF) (81.3%) and butanol fraction (BF) (80.3%). The lowest faecal egg counts (FEC) and highest FEC at 21 days post-treatment were observed in the group treated with albendazole (99.2%) and CME at 800 mg/kg (96.9%). Deparasitization at 200 mg/kg caused by ALB was (93.8%), while at 200, 400 and 800 mg/kg, CME was (77.5%, 87.5% and 91.86%), BF was (75.51%, 79.61% and 85.73%) and EAF was (73.48%, 75.5% and 81.63%), respectively. At post-mortem, broiler chickens infected with A. galli and treated with CME, BF and EAF at 200 mg/kg had desquamation of the villi while at 400 and 800 mg/kg treatments, the intestines were intact.ConclusionThe extract and fractions of V. amygdalina were found to possess anthelmintic activity against A. galli due to the inhibition of embryonation of eggs and the reduction in faecal egg count; further research is required to fully ascertain their mechanism of action of the extract.

Comparative analysis on transcriptomics of ivermectin resistant and susceptible strains of Haemonchus contortus.

BackgroundIvermectin (IVM) is one of the most important and widely used anthelmintics in veterinary medicine. However, its efficacy is increasingly compromised by widespread resistance, and the exact mechanism of IVM resistance remains unclear for most parasitic nematodes, including Haemonchus contortus, a blood-sucking parasitic nematode of small ruminants.MethodsIn this study, an H. contortus IVM-resistant strain from Zhaosu, Xinjiang, China, was isolated and assessed by the control test, faecal egg count reduction test (FECRT) and the larval development assay (LDA). Subsequently, comparative analyses on the transcriptomics of IVM-susceptible and IVM-resistant adult worms of this parasite were carried out using RNA sequencing (RNA-seq) and bioinformatics.ResultsIn total, 543 (416 known, 127 novel) and 359 (309 known, 50 novel) differentially expressed genes (DEGs) were identified in male and female adult worms of the resistant strain compared with those of the susceptible strain, respectively. In addition to several previously known candidate genes which were supposed to be associated with IVM resistance and whose functions were involved in receptor activity, transport, and detoxification, we found some new potential target genes, including those related to lipid metabolism, structural constituent of cuticle, and important pathways such as antigen processing and presentation, lysosome, autophagy, apoptosis, and NOD1-like receptor signalling pathways. Finally, the results of quantitative real-time polymerase chain reaction confirmed that the transcriptional profiles of selected DEGs (male: 8 genes, female: 10 genes) were consistent with those obtained by the RNA-seq.ConclusionsOur results indicate that IVM has multiple effects, including both neuromuscular and non-neuromuscular targets, and provide valuable information for further studies on the IVM resistance mechanism in H. contortus.Graphical Supplementary InformationThe online version contains supplementary material available at 10.1186/s13071-022-05274-y.

Eprinomectin and Moxidectin Resistance of Trichostrongyloids on a Goat Farm in Austria.

Anthelmintic resistance (AR) of trichostrongyloids is widespread in Europe, but there is no up-to-date information on the spread of AR in caprine parasites in Austria. Eprinomectin (EPR) is currently the only anthelmintic drug of the macrocyclic lactones registered for goats in Europe. The aim of the present study was to gather information regarding the efficacy of anthelmintics against trichostrongyloids on a dairy goat farm in Austria with reported treatment failure of macrocyclic lactones and to determine the presence of different trichostrongyloid genera. Faecal egg count reduction tests (FECRT) using Mini-FLOTAC were performed with eprinomectin (EPR) and moxidectin (MOX). Egg count reduction, calculated with the R package egg-Counts, was 44% for EPR and 86% for MOX, confirming AR of trichostrongyloids for both compounds. The most frequently detected genus in larval cultures was Haemonchus, followed by Trichostrongylus. This is the first report of MOX resistance in caprine trichostrongyloids in Europe. Failure of EPR and MOX to control trichostrongyloid infections is a severe threat to dairy goat farming, since other compounds must not be applied in goats used for milk production. Haemonchus contortus is one of the most pathogenic parasites of small ruminants and can quickly develop AR. Thus, immediate action should be taken to slow the further spread of AR in this and other roundworm species of ruminants in Austria.

Anthelmintic Potency of Garlic (Allium sativum) and Neem (Azadirachta indica) combination As Herbal Anthelmintic in Lactating Karan Fries Cows

Gastro-intestinal parasites affect the health and production performance of dairy cows under tropical and sub-tropical conditions. This study was conducted to evaluate the anthelmintic efficacy of herbal anthelmintic (Neem and Garlic combination) as an effective alternative for chemical dewormers which has chemical toxicity and resistance problems in dairy cows. For this, EPG count for gastrointestinal parasites, body weight and BCS of cows were studied. Freshly calved crossbred KF (n=28) cows were selected and divided into 4 groups (T1, T2, T3, T4), each having 7 cows. The cows of T1 were used as control; in T2, cows were provided the commercial (synthetic) dewormer; in T3 cows were provided with a dose of combination of garlic and neem in the ratio of 1:5 @ 4g/kg body wt. at 7 days after parturition and in T4, in addition to first dose at 7 days, a second dose was also supplemented at day 60. Sampling for fecal sample was done on 0, 1, 2, 3, 4, 5, 6, 7, 8 fortnights relative to the deworming treatment. The EPG counting was done by using McMaster counting chamber. The average fecal egg count (FCE) reduction was significantly (P<0.05) maximum in T2 (83.20%) group followed by T4 (77.48%). The BCS and FCE were found significantly (P<0.05) better in all the anthelmintic treated groups compared to control group. However, the FCE was significantly (P<0.05) better in herbal treated groups (T3 and T4) compared to the synthetic anthelmintic treated group (T2). Based on the findings, it could be concluded that Garlic and Neem combination is effective herbal dewormer/anthelmintic and might be used against nematodes in dairy cattle as an effective alternative of synthetic anthelmintics drugs.Â

Equine strongylids: Ivermectin efficacy and fecal egg shedding patterns.

Equine cyathostomins are ubiquitous in grazing horses around the world and a main target in parasite control programs. Anthelmintic resistance has been reported with increasing frequency in these parasites over the past decades, and recent findings of fulminant resistance to the macrocyclic lactone class have raised severe concerns. This study aimed to evaluate ivermectin efficacy in cohorts of yearlings and mares present on four different farms in Central Kentucky. Strongylid egg counts were determined with an automated egg counting system, and the percent fecal egg count reduction (FECR) was calculated using a hierarchical Bayesian analysis. Novel principles were used for classification of groups to either no signs of anthelmintic resistance, evidence of resistance, or inconclusive. Furthermore, an epidemiological analysis was conducted evaluating the possible influence of pregnancy status, time of foaling, and year of arrival on mare strongylid egg shedding levels. A total of 102 yearlings and 247 mares were enrolled in the study. Evidence of ivermectin resistance was documented in one group of yearlings with a mean FECR of 91.2% and a 95% credible interval of 84.0-95.8. The results from one mare group and one additional yearling group were deemed inconclusive, whereas the remaining five groups displayed no evidence of ivermectin resistance. Strongylid shedding in the mares was not positively associated with any of the evaluated factors. This study is the first to demonstrate ivermectin resistance in US bred horses, and the findings emphasize the need for routine monitoring of anthelmintic efficacy on horse farms.

Análisis de expresión del gen de la P-glicoproteína en la resistencia a la ivermectina en ovinos naturalmente infectadas con Haemonchus contortus

The upregulation of P-glycoprotein genes in Haemonchus contortus suspected of ivermectin resistance (IVM-Res) was studied in sheep farms. A faecal egg count reduction test (FECRT) was used to evaluate IVM-Res on four farms (from A to D). Faecal samples positive to gastrointestinal nematodes (GINs) were used to identify infective larval stages (L3) pre- and post-IVM treatment by Polymerase Chain Reaction (PCR) test. Ten P-glycoprotein (pgp) genes were analysed to estimate the over expression level in H. contortus L3. Genes were quantified using the Retro Transcription–real time PCR technique. FECRT indicated low IVM efficacy on the four farms from zero to 33% of eggs per gram and Haemonchus, Cooperia and Trichostrongylus were the GINs identified after IVM treatment. H. contortus isolates displayed different pgp gene upregulation levels (p < 0.05): pgp4 from 19.03 to 25.96-fold on four farms; 3 and 16 pgp from 32.19 to 134.21-fold on three farms; 1, 2 and 12 pgp from 7.14 to 56.43-fold on two farms; 10 and 11 pgp from 6.82 to 32.86-fold on one farm. In conclusion, the examination of FECRT showed low IVM efficacy against GINs. Additionally, pgp3, 4 and 16 were the most frequent genes involved in sheep farms with IVM-Res problems in relation to IVM resistant H. contortus.

Increasing resistance to multiple anthelmintic classes in gastrointestinal nematodes on sheep farms in southwest England.

BackgroundAnthelmintic resistance (AR) in gastrointestinal nematodes (GIN) is increasing globally, and farmers are encouraged to adopt sustainable control measures. Haemonchus contortus is increasingly reported in the UK, potentially complicating effective GIN control.MethodsFaecal egg count reduction tests (FECRT) were conducted on 13 farms in north Devon, England, UK in 2016. Relative abundance of H. contortus was quantified using peanut agglutinin staining and used to estimate faecal egg count reduction percentages (FECR%) using the eggCounts R package.ResultsOn average, farms had GIN resistance to three anthelmintic classes. No farms had susceptibility to all anthelmintics tested. AR was more prevalent in 2016 than on the same farms in 2013. H. contortus was present on 85% of the farms tested and comprised on average 6% (0%–52%) of GIN eggs before treatment. Resistance or suspected resistance to all anthelmintics tested was observed in this species on different farms.ConclusionThe results demonstrate diversity of AR profiles on farms, apparent progression of AR within a 3‐year period, and challenges detecting AR in mixed‐species infections. Where possible, interpretation of mixed‐species FECRT should take into account the relative abundance of species pre‐ and post‐treatment to identify pragmatic treatment options targeting individual genera.

Moxidectin: A Viable Alternative for the Control of Ivermectin-Resistant Gastrointestinal Nematodes in Beef Cattle

Abstract The increasing prevalence of anthelmintic resistance in cattle especially for avermectins, is a challenge for controlling parasites in some herds. Thus, field studies demonstrating the increase in productivity by the use of anthelmintic formulations, even when a suboptimal treatment (efficacy below 95%), can contribute to the development of gastrointestinal nematodes control programs in beef cattle. The objective of the present study was to evaluate the anthelmintic efficacy and productive performance in pasture-raised beef calves, treated with macrocyclic lactones. A Split plot in time randomized block design was used to assess weight gain and reduction in fecal egg count (FECs) of treatments: 1% moxidectin (1% MOX), ivermectin (IVM) and abamectin (ABM) (2.25% IVM+1.25% ABM), 4% IVM, 3.15% IVM and placebo. For the evaluation of FECs and weight gain of the animals, individual samples were collected seven days before treatment and, +14, +30, +56, +91 and +118 days post-treatment (DPT). The efficacies in the 14th DPT were: 72.3% (1% MOX), 22.1% (4% IVM), 22% (2.25% IVM + 1.25% ABM) and 0% (3.15% ivermectin). 1% MOX was the only treatment that resulted in a significant increase in weight gain of the animals compared to the placebo group after 118 days of treatment, with a difference of 7.6 kg. Therefore, MOX remains a viable alternative for the control of helminths resistant to avermectins and still capable of resulting in significant productive gains, even with an efficacy below 95%.

Total Failure of Fenbendazole to Control Strongylid Infections in Czech Horse Operations.

The control of strongylid infections has become challenging globally for equine practitioners due to the development of anthelmintic resistance. Comprehensive information on anthelmintic resistance in the Czech Republic, however, is still lacking. This study monitored the current efficacy of fenbendazole, pyrantel embonate, ivermectin and moxidectin. Forty-eight of 71 operations met the criteria (≥6 horses with ≥200 eggs per gram), with 969 fecal egg count reduction tests performed. Anthelmintic resistance was evaluated on an operation level based on fecal egg count reduction (FECR) and the lower limit of the 95% credible interval (LLCI) using Bayesian hierarchical models. General anthelmintic efficacy across all operations was assessed by posterior FECRs and the occurrence of sub-zero efficacies. Ivermectin and moxidectin demonstrated excellent efficacy (FECR 99.8–100%; 99.4–100 LLCI) in 45 and 23 operations, respectively, pyrantel embonate demonstrated sufficient efficacy in 15 operations and resistance was suspected in seven operations (FECR 88.1–99.1%; 72.5–98.5 LLCI). Fenbendazole, however, was not effective in a single operation (FECR 19.1–77.8%; 8.1–50.1 LLCI) out of 18. Fenbendazole had the highest probability of sub-zero efficacy (29.1%), i.e., post-treatment fecal egg counts exceeded the pre-treatment counts. Our data indicate an increase in the development of anthelmintic resistance, resulting in total failure of fenbendazole and a reduced efficacy of pyrantel embonate. Introducing advanced approaches of parasite control in the Czech Republic to slow the spread of anthelmintic resistance is thus needed.

Anthelmintic Properties of Essential Oils to Control Gastrointestinal Nematodes in Sheep-In Vitro and In Vivo Studies.

Herbal products such as essential oils may play a promising role in the treatment of infections caused by gastrointestinal nematodes (GINs). The aim of this study was to evaluate the in vitro potential of 11 essential oils (EOs) and one binary combination of isolated EO compounds, as well as the in vivo anthelmintic efficacy of two EO formulations. Four GIN genera were identified in the coproculture examination: Haemonchus, Trichostrongylus, Teladorsagia and Chabertia. The in vitro egg hatch test (EHT) was performed at six different concentrations (50, 12.5, 3.125, 0.781, 0.195 and 0.049 mg/mL) for each EO, whereas in the in vivo faecal egg count reduction test (FECRT), each EO sample was diluted in sunflower oil and orally administrated at a dose of 100 mg/kg to the different group of animals. In the EHT, the EOs of Origanum vulgare, Foeniculum vulgare, Satureja montana, Satureja hortensis and two types of Thymus vulgaris were the most effective. The dominant compounds of these EOs were carvacrol, thymol, anethol, p-cymene and γ-terpinene, indicating their importance for the anthelmintic activity. In the FECRT, both T. vulgaris EO type 1 and linalool:estragole combination show an anthelmintic potential with a mean effect on FECR of approximately 25%. The results suggest the possible role of tested EOs as anthelmintic agents in sheep farms, although further in vivo tests are needed.

Parasitofauna and current status of anthelmintic resistance in Latvian sheep farms.

Background and Aim:Parasitic invasions, especially gastrointestinal nematodes, are widespread and are one of the main problems in sheep farms. For this reason, sheep are dewormed more often than other livestock species, often several times a year. Concerns about antiparasitic resistance from the farmers and veterinarians have arisen because, on some farms, antiparasitic drugs are used routinely for very long periods. There are no data available on anthelmintic resistance in gastrointestinal nematodes in sheep in Latvia. Our work aimed to determine the most common endoparasites in sheep and the degree of anthelmintic resistance on sheep farms in Latvia.Materials and Methods:All sheep (577) underwent a coprological examination before the start of the study, and only sheep diagnosed with more than 200 McMaster eggs per gram of feces were included in the study. A fecal egg count reduction (FECR) test was performed on 20 sheep flocks in Latvia.Results:In Latvia, sheep were most commonly infected with Eimeria spp. 97% (confidence interval [CI] 95% 96-98). The second most commonly diagnosed species were Trichostrongylidae 91% (CI 95% 89-93) and Strongyloides spp. 76% (CI 95%, 72-79). The ivermectin (IVM) FECR was 0.74% (0.73-0.74), showing resistance in all sheep farms included in this study. Albendazole (ABZ) FECR 0.89% (0.88-0.89) was effective.Conclusion:This study showed that the most popular deworming drugs (ivermectin, albendazole) in Latvia are ineffective in sheep. Additional studies on the use of IVM+ABZ combinations for deworming sheep should be performed.

Anthelmintic Drug Resistance of Gastrointestinal Nematodes of Naturally Infected Goats in Haramaya, Ethiopia.

Gastrointestinal parasites and their anthelmintic resistance are major constraints to goat production in Ethiopia. Experimental investigation by faecal egg count reduction test (FECRT) and larval cultures were used to assess the occurrence of anthelmintic resistance in naturally infected goats with gastrointestinal nematodes (GIN) in Haramaya, Ethiopia. One hundred goats with a minimum of 150 eggs per gram (EPG) count were selected and randomly divided into five groups, 20 goats in each group, four treated and one untreated group. The result of the faecal egg count reduction test percentage (FECRT%) and the lower 95% confidence limit showed the presence of anthelmintic resistance for all tested drugs except tetramisole. FECRT% and lower 95% confidence limit were 69.9% and 36.9 for albendazole, 84.3% and 66.1 for tetraclozan, 95.7% and 87.4 for tetramisole, and 71.1% and 38.2 for ivermectin, respectively. Trichostrongylus, Teladorsagia, and Haemonchus showed anthelmintic resistance for tested drugs. Coproculture from different treatment groups revealed Trichostrongylus (69.2% in ivermectin and 59.6% in albendazole) were the predominant nematode followed by Teladorsagia (21.9% in albendazole and 14.7% in ivermectin). In tetraclozan treatment group, Trichostrongylus (42%) and Teladorsagia (41.3%) were comparable, followed by Haemonchus (13%). In group treated with tetramisole, Teladorsagia (54.3%) were the most frequently detected nematode followed by Trichostrongylus (25.7%) and Haemonchus (11.4%). Therefore, this study demonstrated the presence of multidrug resistant nematodes that may limit the productivity of goats. Moreover, further studies covering wider areas of Ethiopia and mechanisms of nematode resistance need to be studied in the future.

Anthelmintic Resistance of Gastrointestinal Strongyles Infecting Sheep in Nziih, West Cameroon

Aims: This study aimed to investigate the levels of efficacy of anthelmintics that were most commonly used in sheep farms in Nziih locality.
 Study Design: Longitudinal prospective study.
 Place and Duration of Study: The study was carried out in Nziih locality in August 2019 and September 2020.
 Methodology: Resistance against Albendazole (12.5 mg/kg) and Ivermectin (0.2 mg/kg) was evaluated using faecal egg count reduction test in naturally occurring gastrointestinal strongyles of sheep in Nziih. A total of 300 young animals were randomly selected from 5 farms in 2019 and in 2020. Faecal samples were collected from each animal on the first day of treatment (D0) and collected again 14 days later (D14). Faecal Egg Counts were performed using the Willis and Mac Master techniques and resistance was declared when faecal egg count reduction (FECR) was less than 95 % and the lower limit of confidence interval (LCI) less than 90%. Pooled faecal samples for each treatment group were set for D0 and D14 to identify resistant strongyles genera by calculating persistent larval rate (PLR).
 Results: Resistance against Ivermectin was detected while there was none against Albendazole. Moreover, it was declared only in 2 farms out of the 5 selected. From 2019 to 2020, the status of resistance has shifted from suspicion to resistance for ivermectin and from absence of resistance to suspicion to Albendazole. Resistance was recorded in 2 sites: Pastorale1 (FECR= 85 %, LCI= 42.61 %) and Pastorale 3 (FECR=90.5 %, LCI= 72.26 %) in large flock herds and in farms where sheep were dewormed at least 4 times per year. Trichostrongylus were more persistent than Haemonchus and Oesophagostomum/Chabertia with PLR of 21.22 %, 13.71 %, and 7.40 % respectively.
 Conclusion: Anthelmintics must be used correctly in conjunction with farmer education in Nziih.

Confounding factors affecting faecal egg count reduction as a measure of anthelmintic efficacy.

Increasing anthelmintic resistance (AR) in livestock has stimulated growing efforts to monitor anthelmintic effectiveness (AE) on livestock farms. On-farm assessment of AE relies on measuring the reduction in faecal egg count (FEC) following treatment; and if conducted rigorously, qualifies as a formal FEC reduction test (FECRT) for AR. Substantial research effort has been devoted to designing robust protocols for the FECRT and its statistical interpretation; however, a wide range of factors other than AR can affect FEC reduction on farms. These are not always possible to control, and can affect the outcome and repeatability of AE measurements and confound the on-farm classification of AR using FECRT. This review considers confounders of FEC reduction, focusing on gastrointestinal nematodes of ruminants, including host and parasite physiology and demography; pharmacokinetic variation between drugs, parasites and hosts; and technical performance. Drug formulation and delivery, host condition and diet, and seasonal variation in parasite species composition, can all affect AE and hence observed FEC reduction. Causes of variation in FEC reduction should be attenuated, but this is not always possible. Regular monitoring of AE can indicate a need to improve anthelmintic administration practices, and detect AR early in its progression. Careful interpretation of FEC reduction, however, taking into account possible confounders, is essential before attributing reduced FEC reduction to AR. Understanding of confounders of FEC reduction will complement advances in FECRT design and interpretation to provide measures of anthelmintic efficacy that are both rigorous and accessible.

Multicenter randomized, and blinded European field study evaluating the efficacy and safety of Felpreva®, a novel spot-on formulation containing tigolaner, emodepside and praziquantel, in treating cats with mixed infection with intestinal nematodes, cestodes and/or lungworms

This paper describes a multicentric field study which has evaluated the safety and efficacy of a novel spot on formulation containing emodepside 2.04% w/v, praziquantel 8.14% w/v and tigolaner 9.79% w/v (Felpreva®, Vetoquinol) when administered at the intended commercial dose of 0.15 ml/kg body weight to privately owned cats infected with major intestinal nematodes (Toxocara cati, Toxascaris leonina, Ancylostoma tubaeforme, Uncinaria stenocephala) and/or cestodes (Dipylidium caninum, Taenia taeniaeformis) and/or lungworms (Aelurostrongylus abstrusus, Troglostrongylus brevior). A total of 219 cats from 26 veterinary clinics located in Albania, Greece, Hungary, Italy and Portugal were included in the study. Feces from the cats were examined on a single occasion between Study Day −7 and Day 0 (baseline) and post-treatment (i) twice between Day 7 and Day 14 (± 2) (for intestinal helminths) or (ii) twice between Day 21 (± 2) and Day 28 (± 2) (for lungworms). Cats were allocated into two groups at a ratio of 2:1 (Felpreva®: Profender®, i.e. a commercial control product containing emodepside and praziquantel). Cats infected with intestinal helminths were treated once on Day 0 (i) with Felpreva® (Group 1) or (ii) with Profender® (Group 2). Animals infected with lungworms received a second treatment with Profender® on Day 14 (± 2) regardless of group allocation. Faecal egg or larval count reduction for Felpreva® was 97.47% for intestinal nematodes and 96.80% for lungworms. No cats infected with cestodes at baseline resulted positive after treatment with Felpreva®. However, the low number of cats (n = 10) did not allow for a statistical analysis to be performed. Non-inferiority of Felpreva® compared to Profender® was statistically demonstrated for all target intestinal and respiratory parasites. No adverse events nor application site reactions were observed. These results show that the new topical combination product Felpreva® is highly safe and efficacious in treating infections caused by major species of feline intestinal nematodes, cestodes and lungworms under field conditions.

Anthelmintic resistance status of goat gastrointestinal nematodes in Sing Buri Province, Thailand.

Background and Aim:Promotions of goat farming by both public and private sectors encouraged considerable goat raising in central Thailand. Gastrointestinal nematodes (GIN) infection is a major health and economic problem; however, evidence of resistance to broad-spectrum anthelmintics is frequently reported. Investigation of anthelmintic resistance (AR) status and identification of factors related to the development of AR is important components for sustainable GIN control. However, no information is available on this topic in the study area. The present study aimed to gather information on GIN control practices and to evaluate the effectiveness of albendazole, ivermectin, and levamisole for treating GIN infestation in goat herds in Sing Buri Province.Materials and Methods:Twenty-nine herds were randomly selected. Information on management practices was collected by face-to-face interview using a structured questionnaire. Three field experiments for routinely used anthelmintics, including albendazole, ivermectin, and levamisole were conducted from June 2019 to November 2019. Fecal samples were collected pre- and post-treatment and examined for fecal egg count reduction to determine the status of anthelmintic resistance of goat GIN.Results:Several improper practices were identified that lead to AR, especially chronic use of albendazole and ivermectin. All herds were considered resistant to albendazole and ivermectin, and levamisole resistant nematodes were detected in two herds. AR was strongly linked with the continuous use of anthelmintics.Conclusion:Levamisole, which was still effective in the province, should be used with caution to minimize the selection of resistant strains. Farmers should be provided with updated information for sustainable parasite control. Further, the efficacy of anthelmintics should be routinely monitored.

Anthelminthic resistance of gastrointestinal nematode parasites of West African Dwarf goats in Ikwuano LGA, Abia State, Nigeria

Goat production in Nigeria has faced a major constraint resulting from parasitic infections, notably the parasitic gastrointestinal (GI) nematode which has resulted in high morbidity, mortality, high cost of treatment and high economic losses. Another problem encountered in the treatment of gastrointestinal nematode infection is anthelmintic resistance, hence, the need to investigate the anthelmintic resistance status of GI nematodes of West African Dwarf (WAD) goats in Ikwuano area of Abia State, Nigeria. A faecal egg count reduction test (FECRT) was carried out in naturally infected WAD goats. A total of 60 WAD goats were randomly assigned into 3 groups of 20 WAD goats in each group and screened for GI nematode eggs. Group A treated with ivermectin, group B was treated with levamisole and group C was treated with fenbendazole. The percentage reductions in FEC in male and female WAD goats in ivermectin treated group were 72.42% and 67.98%, Levamisole treated group were 61.67% and 65.22% in male and female WAD goats respectively and 59.50% and 52.63% for male and female in fenbendazole treated group. The percentage reduction of FEC in young and Adult WAD goats treated with ivermectin were 63.05% and 70.52%, and 58.08% and 67.04% for levamisole treated group respectively, while fenbendazole treated group had 60.03 and 54.08% reduction respectively. Resistance was observed in all the anthelmintic drugs used, which poses a huge threat to livestock production in the study area.