Faecal Reduction Research Articles

Anthelmintic resistance in commercial sheep farms in Costa Rica.

Forty-eight commercial sheep farms were sampled between the years 2017 and 2019 to evaluate the percentage of reduction of the three families of broad-spectrum anthelmintic drugs available in Costa Rica - benzimidazoles (albendazole), macrocyclic lactones (ivermectin) and imidazothiazoles (levamisole) - in grazing animals by using the fecal egg count reduction test. Animals were selected based on their egg per gram counts after their fecal samples were processed by a modified McMaster technique. The remaining fecal samples were taken to the laboratory for fecal culture and larval identification. The prevalence of farms with albendazole resistance was 100%, ivermectin 96% and levamisole 17%. Seven (n=47) farms resulted with triple resistance, 39 with double and 1 farm was resistant to 1 AH tested. Haemonchus spp. was the most commonly isolated parasite in pre- and post-treatment larval culture. This is the first report of Oesophagostomum spp. and Teladorsagia sp. resistant to albendazole, Oesophagostomum spp., Teladorsagia sp., Chabertia sp. and Cooperia sp. resistant to ivermectin, and the presence of strains of Haemonchus spp. and Trichostrongylus sp. resistant to the 3 anthelmintics tested. The results of this study demonstrate that anthelmintic resistance is widespread, particularly in Haemonchus spp., and that the major drugs available in the country have lost much of their effectiveness against sheep nematodes.

English

Helminths have been a serious trouble for the farmers due to their adverse effects on small ruminant production. Hemonchus contortus (H. contortus) and Fasciola hepatica (F. hepatica) are highly pathogenic and pose serious threat in co-existence. Because of increasing threat of anthelmintic resistance, alternative methods are being investigated and the herbal remedies stand the most prominent due to their efficacy and availability. Anthelmintic activity of the herbal mixture was evaluated in goats. Adult goats were selected at Livestock Production and Research Centre (LPRI) Bahadarnagar, Okara and were examined for helminth eggs in their feces. Twenty-four goats having almost similar egg per gram (EPG) of feces values of H. contortus and F. hepatica were selected and allocated to four groups of equal size. Herbal mixture was administered at dose rate of 1400, 1200 and 1000 mg/kg to each member of groups G1, G2 and G3, respectively on day 0, 7, 14 and 21 of the trials, while group G4 served as negative control receiving no medicine/herbal mixture. Trials continued for 30 days and data about EPG, fecal egg count reduction, complete blood count and serum biochemistry were collected before administration of herbal mixture at day 15 and day 30 of trial while animals were weighed before initiation of trial (day 0) and at the end of trial (day 30). All treatments showed a significant reduction in fecal egg count as compared to control group. Maximum fecal egg count reduction was observed in animals of group G1, which is 91.35% for H. contortus and 82.35% for F. hepatica. There was a slight increase in weight gain ratio of the treated animals in respective decreasing order with G1 having highest weight gain. An increase in erythrocyte count, pack cell volume and hemoglobin concentration was recorded while non-significant effect was observed on serum parameters. The results of this trial suggested that herbal dewormer is effective and can be an option for integrated management strategies for nematodes and trematodes control in the goats

26 Copper oxide wire particles to complement control of gastrointestinal nematodes with levamisole and/or albendazole in lambs

Abstract Due to high prevalence of anthelmintic resistance (AR), complementary approaches to anthelmintic use to control gastrointestinal nematodes (GIN) in sheep are necessary. Copper oxide wire particles (COWP) are effective against Haemonchus contortus but not other GIN, and FAMACHA aids to minimize further development of AR. The objective was to determine the efficacy of COWP alone or in combination with levamisole, albendazole, or a 3-way combination to control GIN known to have AR to these anthelmintics. Naturally infected Katahdin lambs were selectively dewormed based on FAMACHA© and/or packed cell volume (PCV). If FAMACHA© scores were 3, 4, or 5, lambs received 1 g COWP alone (n = 120), COWP and levamisole (n = 47) or albendazole (n = 6), or a 3-way combination (n = 10), respectively. Untreated lambs were included (CON; n = 31). Feces and blood were collected on days 0 (day of deworming) and 14 for determination of fecal egg counts (FEC) and FEC reduction (FECRED) and PCV. Data were analyzed using repeated measures in a mixed model. The mean FECRED was greater for the combination of levamisole and COWP than COWP alone (P < 0.001). In a mixed GIN population, COWP in combination with levamisole increased the efficacy of FECRED of H. contortus and other GIN genera present, offering greater GIN management in the presence of resistance to these anthelmintics.

A new paraprobiotic-based treatment for control of Haemonchus contortus in sheep

Haemonchus contortus is a critical parasite of goats and sheep. Infection by this blood-feeding gastrointestinal nematode (GIN) parasite has significant health consequences, especially in lambs and kids. The parasite has developed resistance to virtually all known classes of small molecule anthelmintics used to treat it, giving rise in some areas to multidrug resistant parasites that are very difficult to control. Thus, new anthelmintics are urgently needed. Bacillus thuringiensis (Bt) crystal protein 5B (Cry5B), a naturally occurring protein made by a bacterium widely and safely used around the world as a bioinsecticide, represents a new non-small molecule modality for treating GINs. Cry5B has demonstrated anthelmintic activities against parasites of monogastric animals, including some related to those that infect humans, but has not yet been studied in a ruminant. Here we show that H. contortus adults are susceptible to Cry5B protein in vitro. Cry5B produced in its natural form as a spore-crystal lysate against H. contortus infections in goats had no significant efficacy. However, a new Active Pharmaceutical Ingredient (API) paraprobiotic form of Cry5B called IBaCC (Inactivated Bacterium with Cytosolic Crystals), in which Cry5B crystals are encapsulated in dead Bt cell wall ghosts, showed excellent efficacy in vitro against larval stages of H. contortus and relative protein stability in bovine rumen fluid. When given to sheep experimentally infected with H. contortus as three 60 mg/kg doses, Cry5B IBaCC resulted in significant reductions in fecal egg counts (90%) and parasite burdens (72%), with a very high impact on female parasites (96% reduction). These data indicate that Cry5B IBaCC is a potent new treatment tool for small ruminants in the battle against H. contortus.

Treatment of primate platynosomosis: A word of caution about the use of praziquantel in marmosets

The successive reports of Platynosomum illiciens in Neotropical captive primates have increased interest in platynosomosis; however, its treatment is little known. Callithrix penicillata (n=10) naturally and chronically infected with P.illiciens were treated with praziquantel (25mg/kg BW, three s.c. doses at 24hours intervals), and coproparasitological tests performed over 67days. The proportions of primates with a reduction in fecal egg counts (FEC) or negative results progressively increased after treatment, and at the last fecal tests, marmosets were negative. Although all primates tolerated the initial days of study well, 40% (4/10) of them died between the 8th and 16th days after the onset of treatment. Clinical signs and necropsies indicated the occurrence of hepatic involvement, biliary obstruction, and cholangitis. Marmosets with a higher previous FEC were more likely to die after treatment. Use of praziquantel should be considered carefully on a case-by-case basis.

Experimental evidence for the lack of sensitivity of in vivo faecal egg count reduction testing for the detection of early development of benzimidazole resistance.

The objective of this study was to compare the results of an in vitro egg hatch test (EHT), micro-agar larval development test (MALDT) and in vivo faecal egg count reduction test (FECRT) between worm strains obtained from goats and sheep identically infected with the gastrointestinal parasitic nematode Haemonchus contortus. Results from the in vivo and in vitro tests were compared with benzimidazole (BZ)-resistance-associated β-tubulin allele frequencies determined using Pyrosequencing™. BZ resistance was not detected by the in vivo FECRT, where reductions of > 99% for both the resistant and the susceptible H. contortus strains were detected in both species. Discriminating doses in EHT and MALDT for the resistant strain indicated a low level (approx. 25%) of resistant individuals. Genotyping indicated that the susceptible strain had 10% BZ-resistant β-tubulin codon 200 alleles and the resistant strain had 26% respective resistant alleles. The in vitro tests and allele-frequency distribution suggested low levels of resistance in both strains; however, the FECRT did not support the evidence of resistant individuals of either strain in either species, suggesting a potential underestimation of low-level resistance in sheep and goats when employing this test.

Nutritional Supplements Containing Cardus mariano, Eucalyptus globulus, Gentiana lutea, Urtica urens, and Mallotus philippinensis Extracts Are Effective in Reducing Egg Shedding in Dairy Jennies (Equus asinus) Naturally Infected by Cyathostomins.

The increasing levels of anthelmintic resistance together with the restrictions in the use of drugs in food producing animals have enforced the search for sustainable alternative approaches for parasite control. The current study aimed to investigate the safety and the efficacy of a commercially available phytotherapic formulation against gastrointestinal strongyles in donkeys. Twenty-two Ragusana jennies (2.6 ± 0.5 years old) were assigned to two equal groups. One group was treated with two doses of a phytotherapic supplement Paraxitebio® containing Cardus mariano, Eucalyptus globulus, Gentiana lutea, Urtica urens, and Mallotus philippinensis, 14 days apart (Group A). One group was used as negative control (Group B). Individual fecal samples were collected at the beginning of the study (T−1), and after 7, 14, and 28 days (T7, T14, T28). Blood samples were collected on T−1 and T28 in order to assess changes in donkeys' hematological profile. After the initial rise in EPG values observed on T7, Group A showed a significant EPG decrease with lower eggs per gram (EPG) count compared to Group B on T28 and an overall fecal egg count reduction of 56.9% on the same time-point. Hematological parameters were within the normal physiological ranges for enrolled donkeys. However, significant differences in the values of RBCs, Hb, MCHC, MCV, WBCs, eosinophils, and basophils were recorded between groups after phytotherapic treatments, with Group A showing a general improvement in the hemogram picture. The phytotherapic supplement used in the current study was helpful in controlling intestinal parasites allowing a significant reduction in the fecal egg count 28 days after treatment. Further studies are needed to better explore the specific mode of action of the plant-derived formulation herein tested as well as to encourage their use as tool for the control of equine strongylosis under multimodal integrated approach in dairy donkey farms.

A Qualitative Market Analysis Applied to Mini-FLOTAC and Fill-FLOTAC for Diagnosis of Helminth Infections in Ruminants.

Helminth infections, mainly by gastrointestinal nematodes (GIN), are one of the main concerns for animal health, welfare and productivity in grazing ruminant livestock worldwide. The use of a sensitive, precise, accurate, low-cost, and easy-to-perform copromicroscopic technique is of pivotal importance to perform reliable fecal egg count (FEC) and fecal egg count reduction test (FECRT), in order to determine the need of anthelmintic treatment, but also anthelmintic efficacy or resistance. This approach is fundamental to a correct and efficient control of GIN. Unfortunately, in worldwide ruminant farm practice, repeated anthelmintic treatments are carried out, without prior diagnosis of infection, contributing to the spread of Anthelmintic Resistance (AR). Tackling this phenomenon, improving mainly the GIN diagnosis and AR status in farm animals, is a priority of the European COST Action “COMBAR—COMBatting Anthelmintic Resistance in Ruminants” and of the STAR-IDAZ International Research Consortium on Animal Health. One of the specific objectives of the COMBAR Working Group 1 (WG1) is to conduct an European market analysis of new diagnostics and develop a business plan for commercial test introduction, leveraging technical know-how of participants. Since the Mini-FLOTAC in combination with the Fill-FLOTAC may be considered a good candidate for a standardized FEC and FECRT in the laboratory, as well as directly in the field, the aim of this study was to conduct SWOT (Strength—Weaknesses—Opportunities—Threats) and PESTEL (Political, Economic, Social, Technological, Environmental, and Legal) analyses of these tools in 20 European countries involved in the COMBAR WG1, in order to identify the opportunities, barriers, and challenges that might affect the Mini-FLOTAC and Fill-FLOTAC commercialization in Europe.

First case of monepantel resistant nematodes of sheep in Sweden

In this study, we describe for the first time monepantel (MOP) resistance in gastrointestinal nematodes (GIN) in a Swedish sheep flock. On the farm, which had recurrent problems with Haemonchus contortus infection, the efficacy of most available anthelmintics (AH) in Sweden (i.e. ivermectin, albendazole, levamisole and monepantel), was monitored. This was done with the faecal egg count reduction test (FECRT) on three different occasions between August 2017 and April 2020. Although, MOP was used in ewes for the first time in this herd in October 2018 and then demonstrated to be highly efficacious (100% reduction), MOP-resistant worms (52% reduction) appeared in lambs already in April 2020. Resistance was detected only after two further rounds of treatment of the lambs after weaning. It is assumed that a contributing factor to this extremely rapid development was related to the fact that ewes and lambs treated during the housing period were let out on clean pasture after treatment. The ewes were treated during the housing period 2018 and grazed a clean pasture the following spring. The same ewes were treated a second time after housing 2018. The lambs were grazed with these ewes in summer 2018 and after weaning they were treated and moved to another clean pasture during the fall 2018. Anthelmintic resistance was also confirmed on two occasions to different compounds of ivermectin and once to albendazole, but not to levamisole which was tested twice. In conclusion, this is the first description of triple resistance to AH drugs in GIN of sheep in Sweden.

Importation of macrocyclic lactone resistant cyathostomins on a US thoroughbred farm

Anthelmintic resistance in equine cyathostomins is both widespread and highly prevalent in the benzimidazole and tetrahydropyrimidine classes; however, reports of resistance to macrocyclic lactone (ML) drugs are sparse and sporadic. This study reports a case of clear ML resistance in a group of Thoroughbred yearlings imported from Ireland to the US in 2019. Fecal egg count reduction (FECR) following ivermectin administered in February 2020 demonstrated 100% reduction in the US bred yearlings, but 93.5%, 70.5%, and 74.5% reduction in three groups of the imported yearlings. The two former groups were then retreated with ivermectin, yielding FECRs of 33.8% and 23.5%, respectively. Horses from these two groups were then assigned randomly to two possible treatments; moxidectin or a triple combination of moxidectin, oxibendazole, and pyrantel pamoate. The groups treated with moxidectin had FECRs of 90.2%, 57.3%, and 50.0%, while the triple combination had a 100% FECR in all treated groups. Subsequently, the efficacy of ivermectin was reassessed in June 2020 yielding FECRs of 99.8%, 87.7%, and 62.0% in the three imported groups. The FECRs of the US bred yearlings all remained in the 99–100% range. This is the first study to clearly demonstrate ML resistance in cyathostomins and to confirm the suspicion through reassessment. These data demonstrate that ML-resistant cyathostomins were imported from Ireland and serve to illustrate that the global movement of horses has the potential to quickly spread ML-resistant parasite isolates around the world. The equine industry is strongly encouraged to routinely monitor anthelmintic efficacy, so occurrence of ML resistant cyathostomins can be detected and appropriate interventions implemented as early as possible.

Anthelmintic Efficacy of Strongyle Nematodes to Ivermectin and Fenbendazole on Working Donkeys (Equus asinus) in and around Hosaena Town, Southern Ethiopia.

Background Gastrointestinal helminth parasite infection is a major influencing factor against profitability of working equines all over the world. Objectives A study was conducted from October 2016 to May 2017 in and around Hosaena to determine the efficacy of benzimidazole (BZ) and avermectin (AVM) chemical groups against strongyle nematodes in working donkeys. Methods A total of 230 donkeys from Hosaena, Soro, Anlemo, and Gombora were randomly allocated into 5 groups of 46 donkeys in each group. All groups, except group 1 (control), were treated with ivermectin 1%, ivertong 10%, fenbendazole, and Fenacure 750 mg, respectively. Fecal samples were collected perrectally before treatment (day 0) and after treatment (day 14), and an egg per gram (EPG) value of >200 was used as a cutoff for inclusion to assess the efficacy of anthelmintics. Results Accordingly, the study revealed that AVM was effective against strongyle nematodes of donkeys with the mean fecal egg count reduction (FECR) of 100% in three study areas and 97.2% in one study area, respectively, whereas BZ resistance was suspected in the areas where the drug was tested, with the mean FECR of less than 94% in the three study areas. The study also revealed that 73% of the donkeys were affected with a severe degree of strongyle infection as determined by EPG, while 10.4% of donkeys were affected with a mild degree of Parascaris equorum infection. Conclusions The findings of the present study are expected to serve as baseline data for future investigations and control actions to design realistic control programs to minimize factors that favor emergence of anthelmintic resistance and improve the overall health of the donkeys. Thus, further detailed studies are needed to determine the factors that reduce anthelmintic efficacy and increase anthelmintic resistance in donkeys.

Untangling conflicting messages

Anthelmintic resistance in gastrointestinal nematodes of cattle has been worsening over the past 2 decades and is now a global problem. Though the problem was originally seen primarily in Cooperia, which is not a highly pathogenic species, we now know that other more pathogenic species have become drug resistant as well. With no new classes of anthelmintics in the cattle product pipeline, we will need to be better stewards of the drugs we have now, as they will need to last us for a long time. Thus, there is a need to use our anthelmintics differently and smarter than in the past. In this paper we present several strategies for improving the sustainability of parasite control in cattle that will both reduce the development of resistance while maintaining good productivity. Furthermore, we should not just assume a drug works or does not work; testing using the fecal egg count reduction test (FECRT) should be performed on every farm. This is the only way to make evidence-based decisions on optimal drug choices. Optimally, the strategies promoted here should have been instituted years ago. However, it is not too late, and the sooner these strategies are implemented widely, the more successful the beef industry will be in controlling parasites both now and in the future.

The use of ITS-2 rDNA nemabiome metabarcoding to enhance anthelmintic resistance diagnosis and surveillance of ovine gastrointestinal nematodes

(300 words)A lack of quantitative information on the species composition of parasite communities present in fecal samples is a major limiting factor for the sensitivity, accuracy and interpretation of the diagnostic tests commonly used to assess anthelmintic efficacy and resistance. In this paper, we investigate the ability of ITS-2 rDNA nemabiome metabarcoding to enhance fecal egg count reduction testing by providing information on the effect of drug treatments on individual parasite species. Application of ITS-2 rDNA nemabiome metabarcoding to fecal samples from ewes from over 90 flocks across western Canada revealed high gastrointestinal nematode infection intensities in many flocks with Haemonchus contortus being the most abundant species followed by Teladorsagia circumcincta and then Trichostrongylus colubriformis. Integration of ITS-2 rDNA nemabiome metabarcoding with pre- and post-treatment fecal egg counting revealed consistently poor efficacy of producer-applied ivermectin and benzimidazole treatments against H. contortus, but much better efficacy against T. circumcincta and T. colubriformis, except for in a small number of flocks. Integration of nemabiome ITS-2 rDNA metabarcoding with Fecal Egg Count Reduction Tests (FECRT), undertaken on farm visits, confirmed that ivermectin and fenbendazole resistance is widespread in H. contortus but is currently less common in T. circumcincta and T. colubriformis in western Canada. FECRT/nemabiome testing did not detect moxidectin resistance in any GIN species but suggested the early emergence of levamisole resistance specifically in T. circumcincta. It also revealed that although poor efficacy to closantel was relatively common, based on total fecal egg counts, this was due to its narrow spectrum of activity rather than the emergence of anthelmintic resistance. This study illustrates the value of ITS-2 rDNA nemabiome metabarcoding to improve fecal egg count resistance testing, perform large-scale anthelmintic resistance surveillance and direct more targeted rational anthelmintic use.

The threat of reduced efficacy of anthelmintics against gastrointestinal nematodes in sheep from an area considered anthelmintic resistance-free

BackgroundThe worldwide increased difficulty to combat gastrointestinal nematode (GIN) infection in sheep, due to progressing anthelmintic resistance (AR), calls for an enhanced and standardized implementation of early detection of AR. This study provides a snapshot of the current AR status against benzimidazoles and macrocyclic lactones in southern Italy, generated with standardized techniques.MethodsOn 10 sheep farms, the efficacy of albendazole (ALB) and either eprinomectin (EPR) or ivermectin (IVM) was evaluated based on the faecal egg count reduction test (FECRT) performed with the Mini-FLOTAC. For each tested drug, 40 sheep were rectally sampled at D0 and sampled again 14 days after the treatment (D14). The FECRT was calculated from individual samples and pooled samples which consist of 5 individual samples. Efficacy was classified as ‘reduced, ‘suspected’ and ‘normal’. Coprocultures were set for D0 and D14 faecal samples of each group. From farms with FECR < 95%, an in vitro egg hatch test (EHT) and a follow-up FECRT using fenbendazole (FBZ) were conducted.ResultsBased on the FECR, high efficacy (from 95.7% to 100%) was observed for ALB and IVM in eight farms (Farms 3–10). On Farm 1 and Farm 2, the efficacy for the macrocyclic lactones was classified as ‘normal’, but ‘reduced’ efficacy was observed for ALB on Farm 1 (FECR = 75%) and ‘suspected’ efficacy on Farm 2 (FECR = 93.3%) with the predominant GIN genus Trichostrongylus followed by Haemonchus at D14. The FEC results of pooled samples strongly correlated with those of individual samples, for FEC at D0 (rs = 0.984; P < 0.0001) and at D14 (rs = 0.913; P < 0.0001). The classifications of efficacy in Farm 1 (FECR = 86.0%) and Farm 2 (FECR = 93.0%) in the follow-up FECRT with FBZ coincide with the main FECRT trial. The in vitro EHT confirmed AR in both farms (Farm 1: 89%; Farm 2: 74%).ConclusionsIn regions like southern Italy, where the negative impacts from AR have played a minor role, efficient monitoring of AR is important in order to evaluate potential risks and being able to promptly respond with countermeasures.

Teladorsagia circumcincta beta tubulin: the presence of the E198L polymorphism on its own is associated with benzimidazole resistance

BackgroundBenzimidazole resistance is associated with isotype-1 β-tubulin gene F200Y, E198A and F167Y SNPs. In this study, the recently described polymorphism E198L was reported and analysed in Teladorsagia circumcincta.MethodsThe benzimidazole phenotypic resistance was measured by the faecal egg count reduction test (FECRT) and the egg hatch test (EHT) using a discriminating dose (DD) in 39 sheep flocks. Around 1000 larvae collected before and after treatment were used for DNA extraction. The resistant species identified in all flocks was T. circumcincta. The resistance alleles frequencies were measured for F200Y and E198A. A 371-bp fragment of the isotype-1 β-tubulin gene was analysed, including the three codons of interest, and a new pyrosequencing assay was designed for testing E198L.ResultsThe percentage of resistant flocks was 35% by FECRT or 26% by EHT; however, F200Y and E198A SNPs were absent in T. circumcincta. The amplification of a 371-bp fragment confirmed the absence of F167Y and F200Y in 6 resistant flocks. Regarding codon 198, all samples after treatment carried a leucine (CTA). A pyrosequencing assay analysed the allele frequencies for the first two bases at codon 198 independently, G/C and A/T. The correlation between C and T frequencies was almost 1 (r = 0.929, P < 0.0001) and the mean value of both was calculated to measure the leucine frequency; this value ranged between 10.4–80.7% before treatment, and 82.3–92.8% after treatment. High and similar correlations were reported between the genotypic variables (C frequency, T frequency or mean of both frequencies) and phenotypic resistance (r > 0.720, P < 0.0001), although negatively associated with the FECRT and positively with the EHT. According to multivariate linear regression analysis, the T frequency was the most significant variable influencing the phenotypic resistance (FECRT or EHT; P < 0.0001). In the EHT, 67.1% of the phenotypic variability is associated with the T frequency but in the FECRT only 33.4%; therefore, the EHT using a DD seems to detect the genotypic resistance more accurately than the FECRT.ConclusionsThe E198L polymorphism can confer BZ resistance on its own in T. circumcincta.

Rampancy of Antinematicidal Resistance Among Gastrointestinal Nematodes in Kurdish Goat Breeds

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The current study was designed to determine the emergence of resistance among gastrointestinal roundworms of native goats against renowned synthetic antinematicidals such as fenbendazole, avermectin and levamisole. To meet the survey requirements, six commercial goat farms, located in Sothern and Western Erbil province-Kurdistan region of Iraq, were chosen after performing qualitative parasitological assays. The study was executed from September to end of November, 2019. From each farm, 30 adult goats were haphazardly divided into two groups, a group (n=15) for treatment and other group (n=15) served as control. The faecal egg count reduction test (FECRT) and egg hatch assay (EHA) have disclosed emergence of resistance against fenbendazole. According to RESO Computer Program, the estimated FECR% in farms 1 and 2 were 70.72 and 79.55, whilst the lower confidence intervals 95% were 63 and 73.8 respectively. The LC50 value of fenbendazole after conducting EHA, calculated through probit analysis, was estimated to be 2.11 μg ml ־¹ (range 1.47-2.34). Regarding avermectin, the computed FECR% in farms 3 and 4 were 93.92 and 92.98, while the lower confidence intervals 95% were 92.91 and 90.7 respectively, which signified the presence of suspicion about prevalence of resistance against avermectin. For levamisole, the calculated FECR% in farms 5 and 6 were 95.99 and 96.38, whilst the lower confidence intervals 95% were 95.1 and 95.7 respectively. Consequently, the parasitic nematodes were susceptible to this synthetic chemotherapeutic in the region

Comparative efficacy of five anthelmintic drugs against a naturally acquired Fasciola species infection in sheep in Jumla, Nepal

Fascioliasis is one of the important parasitic diseases in tropical and subtropical countries which limit productivity of ruminants. The aim of present study was to evaluate the efficacy of five different anthelmintics against liver fluke in a naturally infected sheep flock at Sheep and Goat Research Program, Guthichaur, Jumla. Altogether 30 sheep positive with Fasciola eggs were selected for the study. These 30 sheep were divided into six groups including control one and each group consisted five animals. Sheep of Group I, II, III, IV and V were treated with different anthelmintics viz. Albendazole, rafoxanide, oxyclozanide, oxyclozanide and levamisole combination, and triclabendazole respectively. Faecal samples were obtained from each animal per rectum on the day of treatment and again 1, 3, 7, 14 and 28 days post-treatment. The efficacy of the used anthelmintics was determined by faecal egg count reduction percent in which the fecal egg was investigated by sedimentation technique. The results for oxyclozanide, oxyclozanide and levamisole combination and triclabendazole indicated that these drugs were highly effective with faecal egg count being reduced by 100% by day 14 post-treatment. However, the results for albendazole and rafoxanide groups yielded lower efficacy levels, with faecal egg count reductions 92.8% and 91.8% respectively, over the period 28 days post-treatment. These results are highly indicative for albendazole and rafoxanide resistant Fasciola in sheep on this farm.

Acacia farnesiana pods (plant: Fabaceae) possesses anti-parasitic compounds against Haemonchus contortus in female lambs

Acacia farnesiana pods are rich in secondary metabolites and their biological activities have been recorded as antibacterial, antioxidant and anthelmintic. Previously, an in vitro bioguided study showed the important ovicidal and larvicidal effects of an organic fraction (EtOAc-F) from a hydroalcoholic extract of A. farnesiana pods against Haemonchus contortus. The present study aimed to assess the in vivo anthelmintic effect of EtOAc-F from A. farnesiana pods on the H. contortus faecal egg elimination in female lambs and on the infective larvae (L3) population reduction in coprocultures. The EtOAc-F was obtained from a hydroalcoholic extract from A. farnesiana pods through chromatographic procedures; additionally, some secondary compounds were identified using high-performance liquid chromatography (HPLC). Twenty-one ‘Katahdin’ crossbred female lambs ranging from three to four months of age, with body weights 21.9 ± 0.39 kg were used. Animals were orally infected with H. contortus (L3) by a single dose of 350 L3/kg BW. Three experimental groups (n = 7) were assigned as follows: 1) Control (untreated), 2) Albendazole, as a positive control (at 7.5 mg/kg BW, unique dose) and 3) EtOAc-F (at 100 mg/kg BW, once every third day, with three applications in total). Individual faecal samples were collected once a week for 5 weeks (at days 38, 45, 52, 59 and 66) post-treatment, to measure the faecal egg counts (FEC) and to obtain the H. contortus (L3) population from faecal cultures. The highest FEC reduction caused by EtOAc-F was 67.7%; meanwhile, albendazole showed a total FEC reduction after the second week post-treatment (day 45). On the other hand, the fraction caused an important reduction in the larval population in coprocultures (54.3–68.5%). The phytochemical analysis revealed the presence of galloyl derivatives and flavonoids as major compounds. The A. farnesiana pods could serve as a natural anthelmintic for the control of H. contortus, and perhaps for controlling other parasites of veterinary importance.

Prevalence of gastrointestinal nematodes, parasite control practices and anthelmintic resistance patterns in a working horse population in Egypt.

Anthelmintic resistance is commonly reported in horse populations in developed countries, but evidence in some working horse populations is either lacking or inconclusive. To estimate prevalence of GI nematode infections in working horses in Egypt and to evaluate strongyle resistance to ivermectin, doramectin and fenbendazole. Cross-sectional study. Faecal egg count was performed on 644 working horses from 2 provinces in Egypt. A short questionnaire about horse signalment and worming history was completed for each horse. Horses identified with ≥50 strongyle type egg/g (n=146) underwent faecal egg count reduction testing (FECRT) following treatment with ivermectin (n=33), doramectin (n=33) or fenbendazole (n=30). Risk factors for strongyle (≥200 egg/g) and Parascaris equorum (>0 egg/g) infection were investigated using multivariable logistic regression analyses. The prevalence of low (0-199 epg), medium (200-500 epg) and high (>500 epg) strongyle infection was 88.4%, 5.9% and 5.8%, respectively. P. equorum eggs were detected in 5.1% (n=33) of horses. Strongyle FECR was 100%, 99.97% and 100% following treatment with ivermectin, doramectin and fenbendazole respectively. Anthelmintic treatment in the 12months preceding examination was associated with reduced likelihood of strongyle infection (odds ratio [OR]=0.26, 95% confidence interval [CI]=0.14, 0.47, P<.001). The likelihood of P. equorum infection was significantly associated with horses' age (OR=0.78, 95% CI=0.69, 0.90; P<.001). Male horses were more likely to have P. equorum infection (OR=2.86, 95% CI=1.37, 5.93, P=.005). Nonrandomised selection of study areas and larval cultures was unsuccessful for some samples. There were low prevalence of strongyle and P. equorum infection and no evidence of macrocyclic lactones or benzimidazole resistance in strongyles in the studied working horse population.

The first report of multidrug resistance in gastrointestinal nematodes in goat population in Poland

BackgroundProphylactic anthelmintic treatment with one of three basic classes of anthelmintics (benzimidazoles, macrocyclic lactones and imidazothiazoles) is still the mainstay of control of gastrointestinal nematode infections in small ruminants worldwide. As a consequence, anthelmintic resistance is a serious threat to small ruminant health and production. While the resistance to one class of anthelmintics has already been reported in most of countries, the newly-emerging problem is the resistance to two or even all of classes referred to as multidrug resistance. This study aimed to evidence the presence of multidrug resistance of gastrointestinal nematodes in goats in Poland.ResultsThe combination of one in vivo method (fecal egg count reduction test) and two in vitro methods (egg hatch test and larval development test) performed in two goat herds in the southern Poland showed the presence of gastrointestinal nematodes resistant to fenbendazole and ivermectin in both herds. Moreover, in one herd it revealed the development of resistance to the last effective anthelmintic, levamisole, in response to one-year intensive use. Haemonchus contortus was the most prevalent gastrointestinal nematode in samples in which resistance to benzimidazoles and ivermectin was found, whereas Trichostrongylus colubriformis predominated when resistance to levamisole was observed.ConclusionThis study shows for the first time that multidrug resistance of gastrointestinal nematodes to three basic classes of anthelmintics is already present in goat population in Poland. Moreover, it may indicate that different species or genera of gastrointestinal nematodes are responsible for the resistance to specific anthelmintics.