Faecal Reduction Research Articles

Genome-wide analysis of the response to ivermectin treatment by a Swedish field population of Haemonchus contortus

Haemonchus contortus is a pathogenic gastrointestinal nematode of small ruminants and, in part due to its capacity to develop resistance to drugs, contributes to significant losses in the animal production sector worldwide. Despite decades of research, comparatively little is known about the specific mechanism(s) driving resistance to drugs such as ivermectin in this species. Here we describe a genome-wide approach to detect evidence of selection by ivermectin treatment in a field population of H. contortus from Sweden, using parasites sampled from the same animals before and seven days after ivermectin exposure followed by whole-genome sequencing. Despite an 89% reduction in parasites recovered after treatment measured by the fecal egg count reduction test, the surviving population was highly genetically similar to the population before treatment, suggesting that resistance has likely evolved over time and that resistance alleles are present on diverse haplotypes. Pairwise gene and SNP frequency comparisons indicated the highest degree of differentiation was found at the terminal end of chromosome 4, whereas the most striking difference in nucleotide diversity was observed in a region on chromosome 5 previously reported to harbor a major quantitative trait locus involved in ivermectin resistance. These data provide novel insight into the genome-wide effect of ivermectin selection in a field population as well as confirm the importance of the previously established quantitative trait locus in the development of resistance to ivermectin.

Detection of anthelmintic resistance in nematodes infecting dairy heifers in Puerto Rico

The efficacy of the anthelmintic albendazole (ALB), doramectin (DOR) and ivermectin (IVM) were evaluated in Holstein and Holstein crossbreed dairy heifers using the fecal egg count reduction test (FECRT). Dairy heifers (n=420; ~6 months of age; BW = 149 ± 39.6 kg) were evaluated in 21 dairy farms. All heifers were required to be on pasture and not have been exposed to anthelmintic treatment for a minimum of 3 months. At each dairy farm, a priori, groups of at least 18 heifers were randomly divided to be treated with IVM, or DOR, or ALB following manufacturer's instructions. Fecal samples were collected directly from the rectum 7 days before anthelmintic treatment (d-7), at the time of the treatment (d0), and 14 days after treatment (d14). Only heifers that had an average FEC ³ 100 eggs per gram of feces (average of FEC from day d-7 and d0) were considered in the FECRT. The FECRT was determined by the modified McMaster technique. Of the three-anthelmintic used, ALB (n=142) proved to be the most effective (P < 0.0005) with an efficacy of 67.47% ± 8.43. The efficacy of DOR and IVM did not differ (P = 0.8713). While DOR (n = 130) exhibited a efficacy of 25.50% ± 18.00, IVM (n = 148) exhibited a efficacy of -8.13% ± 19.89 due to an increase in FEC after treatment. Dairy farmers should implement integrated methods of nematode control to preserve the effectiveness of currently available anthelmintics.

Anthelmintic activity of methanol extract of Dennettia tripetala G. Baker (Annonaceae) fruits against Haemonchus contortus in red Sokoto goats.

Haemonchosis is a gastrointestinal parasitic disease of economic importance in ruminants especially sheep and goats. In view of the rising costs of conventional veterinary anthelmintics and the development of resistance by Haemonchus contortus, there is a need to develop alternative ethnoveterinary therapies for the treatment and management of Haemonchosis. This study investigated the anthelmintic activity of Dennettia tripetala G. Baker (Annonaceae) fruits against Haemonchus contortus in red Sokoto goats. The maximum tolerated dose was determined in adult albino rats administered, 3000, 4000, and 5000mg/kg body weight of the crude methanol extract (CME) fraction, and observed over a period of 48h for signs of toxicity and mortality. The in vivo anthelmintic activity was evaluated using 20 kids infected with H. contortus and randomly allocated into 5 groups (1, 2, 3, 4, and 5). Kids in groups 1, 2, and 3 were treated with CME at doses of 1250, 2500, and 5000mg/kg respectively for 3 consecutive days per os. Groups 4 and 5 were treated with albendazole (7.5mg/kg) once and distilled water (5ml) respectively and served as treated and untreated controls. Blood samples were collected for haematology. The maximum tolerated dose of the CME of D. tripetala did not produce observable signs of toxicity or death in all the rats given up to 5000mg/kg. There was significant (P < 0.05) reduction in faecal egg count by CME at doses of 1250mg/kg (91.6%), 2500mg/kg (98.5%), and 5000mg/kg (100%) at day 14 post-treatment. The total plasma protein (TPP) and FAMACHA© scoring values were significantly improved (P < 0.05) in the treated groups. These results indicate that methanol extract and fractions of D. tripetala fruits possess beneficial anthelmintic activity against H. contortus and may be a suitable alternative anthelmintic candidate for the control of haemonchosis in goats.

Anthelmintic Resistance and Its Mechanism: A Review.

Helminths are a various types of parasites causing a major health problem for animals in different parts of the globe. Control of helminthiasis has largely relied on the use of pharmaceutical anthelmintics. Unfortunately, the exhaustive use of anthelmintic drugs has led to a serious and dramatic level of anthelmintic resistance. Anthelmintic resistance is a heritable loss of sensitivity of an anthelmintic in a parasite population that was in the past susceptible to the same anthelmintic. The development of anthelmintic resistance is evident to different helminths of almost every animal species and to different groups of anthelmintic in several continents. Frequent treatment, underdosing, genetics of the parasite, and targeting and timing of mass treatment are predisposing factors for anthelmintic resistance. Upregulation of cellular efflux mechanisms, an increase in drug metabolism, a change in drug receptor sites that reduces drug binding or the functional consequences of drug binding, and a decrease in drug receptor abundance through reduced expression within the parasite are the main mechanisms of anthelmintic resistance. In vivo method like fecal egg count reduction test and in vitro method such as egg hatch assays, larval motility test, larval development test and PCR can be used for the detection of anthelmintic resistance. Proper utilization of anthelmintic drugs, using combined anthelmintic and applying other alternatives are essential strategies to slow down the development of anthelmintic resistance. As anthelmintic resistance is a serious challenge throughout the world, proper utilization of the existing anthelmintics and reducing dependence on anthelmintics should be implemented to reduce its challenge.

Cyathostomin resistance to moxidectin and combinations of anthelmintics in Australian horses

BackgroundCyathostomins are the most important and common parasitic nematodes of horses, with > 50 species known to occur worldwide. The frequent and indiscriminate use of anthelmintics has resulted in the development of anthelmintic resistance (AR) in horse nematodes. In this study we assessed the efficacy of commonly used anthelmintics against cyathostomins in Australian thoroughbred horses.MethodsTwo drug efficacy trials per farm were conducted on two thoroughbred horse farms in the state of Victoria, Australia. In the first trial, the horses on Farm A were treated with single and combinations of anthelmintics, including oxfendazole (OFZ), abamectin (ABM), abamectin and morantel (ABM + MOR), moxidectin (MOX) and oxfendazole and pyrantel (OFZ + PYR), at the recommended doses, whereas the horses on Farm B only received MOX, at the recommended dose. The faecal egg count reduction test (FECRT) was used to determine the efficacy and egg reappearance period (ERP) of anthelmintics. Based on the results of the first trial, the efficacies of MOX and a combination of ABM + MOR were reassessed to confirm their activities against cyathostomins.ResultsOf the five anthelmintic products tested on Farm A, resistance against OFZ, ABM and OFZ + PYR was found, with efficacies of − 41% (− 195% lower confidence limit [LCL]), 73% (60% LCL) and 82% (66% LCL) at 2 weeks post-treatment, respectively. The FECRT showed high efficacies of MOX and ABM + MOR (100%) at 2 week post-treatment and shortened ERPs for these anthelmintics (ABM + MOR: 4 weeks; MOX: 5 weeks). Resistance to MOX was found on Farm B, with a reduced efficacy of 90% (70% LCL) and 89% (82% LCL) at 2 weeks post-treatment in trials one and two, respectively.ConclusionsThis study provides the first evidence of MOX- and multidrug-resistant (ABM and combinations of anthelmintics) cyathostomins in Australia and indicates the need for continuous surveillance of the efficacy of currently effective anthelmintics and large-scale investigations to assess the ERP for various anthelmintics.Graphical

Prevalence of anthelmintic resistant cyathostomins in Prince Edward Island, Canada.

Cyathostomins are the most common parasites of adult horses worldwide. Currently, the three classes of anthelmintics used to treat cyathostomin infections includes benzimidazoles, pyrimidines and macrocyclic lactones. However, due to widespread overuse, cyathostomins have developed varying degrees of resistance to all classes of anthelmintics. Fecal egg count reduction tests (FECRT) are currently used to determine the presence of anthelmintic resistance (AR), while egg reappearance periods (ERP) are used to investigate early macrocyclic lactone resistance. The objective of this study was to investigate the prevalence of cyathostomin pyrantel pamoate and ivermectin resistance, and to determine ERP at Prince Edward Island (PEI), Canada horse farms. In addition, fecal cultures and larval identification were performed to evaluate the prevalence of small and large strongyle egg shedding in PEI. Fecal egg counts (FEC) were performed on 270 horses on 14 horse farms across PEI. Horses with≥ 200 eggs per gram (EPG) met the inclusion criteria and were enrolled in the study (n=101). The median (range) horses per farm was 7.5 (4-11) and 6.0 (4-8) for pyrantel pamoate and ivermectin groups, respectively. Horses were initially treated with 6.6mg/kg of pyrantel pamoate orally (n=101). Fecal egg counts were conducted every two weeks for 8weeks post treatment. Once individual FEC were ≥ 200 EPG, horses were dewormed with 0.2mg/kg of ivermectin orally (n=80), and FEC were performed every 2-3weeks for seven weeks. In this study the ERP was defined as the week the mean FECR were 10% below the initial mean two-week post treatment FECR. Fecal egg count reduction tests and ERP were used to evaluate the efficacy of each anthelmintic. Fecal culture was performed to confirm the shedding of cyathostomin eggs. Fecal egg count reduction tests detected pyrantel pamoate resistance on 5/14 farms. No signs of ivermectin AR were detected, while reappearance of eggs occurred at 4-6weeks and 7-9weeks for pyrantel pamoate and ivermectin, respectively. Fecal culture detected large strongyles on 5/14 farms, which accounted for 0.3% of strongyle type eggs cultured. The prevalence of Strongylus vulgaris among individual horses in this study was 2.8% and was detected on 2/14 farms. These findings will allow us to educate owners and veterinarians on appropriate anthelmintic protocols in PEI and can be used as a baseline for continued monitoring of ERP and anthelmintic resistance in this region.

Assessment of trichostrongyles resistance against anthelmintics commonly used in sheep reared in Dakahlia governorate, Egypt

Objective: To investigate, for the first time, the anthelmintic resistance of different trichostrongyles infecting sheep in Dakahlia governorate, Egypt. Design: Randomized controlled study. Animals: 820 sheep reared within 10 freely grazing herds with infrequent deworming practices.Procedures: Fresh fecal samples were collected; their floats were examined for the trichostrongyle eggs, which were then identified employing the fecal cultures and/or ITS2-PCR amplifications. Sheep (n=500) whose samples had egg counts ≥ 150 eggs per gram (EPG) of feces were selected and divided in each herd into 5 equal groups; each group received one of the tested anthelmintics including albendazole (5 mg/kg BW), levamisole (7.5 mg/kg BW), ivermectin (0.2 mg/kg BW) and doramectin (0.2 mg/kg BW), whereas the fifth group were kept untreated. The EPGs were detected for all groups at the time of treatment and weekly for 10 times post-treatment. Fecal egg counts reduction percentage (FECR%) and egg reappearance periods (ERP) were estimated.Results: The examined herds were mostly infected with Haemonchus contortus; however, few larvae of Trichostrongylus species were detected in fecal cultures of 2 herds. In the untreated groups, the EPGs increased gradually over the time of the experiment; however, no eggs were detected in samples of all treated groups 7 days post treatment resulting in 100% FECR. The macrocyclic lactones (ivermectin and doramectin) displayed longer ERPs than the benzimidazoles (levamisole and albendazole). Conclusion: No anthelmintic resistance was noticed in trichostrongyles-infected sheep population from Dakahlia governorate, Egypt, and the use of ivermectin to treat the trichostrongyles-infected sheep is recommended.

Assessing the Efficacy of Albendazole against Fasciola hepatica in Naturally Infected Cattle by In Vivo and In Vitro Methods.

This study was performed on a cattle farm with a long-term use of albendazole (ABZ) and a permanent history of fasciolosis for comparing in vivo and in vitro methods for the detection of anthelmintic resistance and drug efficacy. A selected group of 10 Charolais cows was treated in autumn 2020 with ABZ at a dose of 7.5 mg/kg body weight. Another group of 10 cows remained untreated as a control. The faecal egg count reduction test was used to determine in vivo efficacy. The percentage reduction of eggs on day 14 after treatment ranged from 77 to 81.8%, depending on the formula used for calculation. The in vitro egg hatch test (EHT) was used as a second diagnostic method. F. hepatica eggs for the EHT were isolated from faecal samples. The test was performed in two versions differing in the length of incubation with ABZ (12 h and 15 d). The percentage of eggs with inhibited development at a concentration of 0.5 μM in both versions of the EHT agreed with the in vivo results. Ovicidal activity at a concentration of 0.5 μM in the 12-h version suggested a reduced efficacy of ABZ (65.40%). An EHT prepared using pooled faecal samples was a prospective method for the detection of efficacy and ABZ resistance in F. hepatica.

Efficacy of Levamisole, Piperazine and their Combination in the Control of Gastrointestinal Worms in Guinea Fowl

Guinea fowl production is gaining prominence in Ghana and the major health problems associated is helminthosis. However, studies on the use of anthelmintics in guinea fowl had been scanty in literature despite research into more effective drug strategies in controlling helminth infections in poultry. This study was carried out to compare the efficacy of piperazine, levamisole and their combination in the control of gastrointestinal worms from August- December 2019. Six-thousand-layer guinea fowls were divided into four groups (1, 2, 3 and 4). Group 1 was treated with piperazine at 100g/100 L of water, Group 2 with levamisole at 100g/200 L of water, Group 3 with a combination of levamisole and piperazine and Group 4 was the control group. All treatments were administered via water medication and the control group was offered plain water. Faecal samples were collected before and after treatment from each bird. Faecal egg count reduction (FECR) rate was determined for each group. Predominant helminth infections from pre- treatment faecal examinations were Ascaridia galli 100 (60.24 %) which was the highest, followed by Heterakis gallinarum 43 (25.90%), Strongyloides avium 15 (9.04%), Raillietina echinobothridia 7 (4.22) and Syngamus trachea 1 (0.6%). Reduction was statistically significant, p-value ˂ 0.0001 at confidence interval of 95%. The percentage reduction in faecal egg count was 143 (35.75%) for piperazine treatment group, 172 (43%) for levamisole treatment group, 350 (87.50%) for piperazine- levamisole combination group and 4 (1.05%) for the control group. The use of piperazine-levamisole combination was more efficacious and recommended in the control of gastrointestinal nematodes in guinea fowl.

The efficacy of a single oral dose of albendazole against soil-transmitted helminthiasis in Ogun State, Nigeria

Soil Transmitted Helminths (STHs) are Neglected Tropical Diseases of global public health importance. This study evaluated the efficacy of albendazole (ALB) amongst primary school children aged 6 – 16 years in STH-endemic communities in Ogun State, Nigeria. Demographic characteristics were obtained and stool samples were collected and analysed by Kato-Katz at baseline and 15 and 21 days post-treatment. All study participants were treated with a single ALB 400 mg tablet. A total of 282 participants were screened at baseline, of which 151 were found to be excreting STH (51.4%) of which A. lumbricoides was the most prevalent STH (n = 137, 48.6%), followed by hookworm (n = 60 children, 21.3%) and T. trichiura (n = 3; 1.1%). The prevalence across the four schools varied from 31.3% to 73.9% for A. lumbricoides, from 6.8% to 56.3% for hookworm, and from 0.0% and 2.2% for T. trichiura infections. Of the 151 children excreting any STH infection at baseline, 131 (86.8%) provided a stool sample 15 and 21 days after treatment. The mean fecal egg counts across these complete cases at baseline was 5,096 (± 13,735) eggs per gram (EPG) for A. lumbricoides, 2,202 (±7,849) for hookworms and 288 (±375) for T. trichiura. Fifteen days after drug administration the therapeutic efficacy, measured as the reduction in mean fecal egg count (FEC) following drug administration (ERR), was 99.7% (95CI: 99.4-99.9) for A. lumbricoides and 69.2% (95CI: 28.7-92.8) for hookworms. The hookworm ERR at day 14 was reduced due to the continued high egg output of one highly infected individual. One week later, 21 days following drug administration, ERR for hookworm also reached satisfactory levels (99.4% (95CI: 98.7-99.8)). This study highlights that ALB still shows satisfactory efficacy to Ascaris and hookworm infections in Ogun State, Nigeria.

Green Veterinary Pharmacology Applied to Parasite Control: Evaluation of Punica granatum, Artemisia campestris, Salix caprea Aqueous Macerates against Gastrointestinal Nematodes of Sheep.

Resistance to anthelmintic drugs in gastrointestinal nematodes (GIN) of sheep is of high concern for livestock production worldwide. In Calabria (southern Italy), many plants have been used in ethnoveterinary medicine for parasite control in small ruminants. Here, we present an in vivo evaluation of anthelmintic efficacy of three plant extracts. The first was based on bark and leaves of Salix caprea, the second and the third were based on the whole plant Artemisia campestris and whole fruit (seeds and peel) of Punica granatum, respectively. Anthelmintic efficacy was evaluated according to the fecal egg count reduction test (FECRT) performed with the FLOTAC technique. The results showed a significant anthelmintic effect of Punica granatum macerate (50%), a low effectiveness of the Artemisia campestris macerate (20%), and a complete ineffectiveness of Salix caprea macerate (0.1%). With these outcomes, we report a P. granatum-based remedy reducing 50% GIN egg output. This result was obtained without using any synthetic drug, paving the way for the employment of green veterinary pharmacology (GVP) as a complementary and sustainable method to reduce the use of chemicals and to counteract anthelmintic resistance.

86 Anthelmintic Resistance in Angus Bulls Participating in Regional Performance Tests

Abstract Resistance to anthelmintics, more commonly referred to as “de-wormers,” has been on the rise in parasites that affect cattle. Parasite infection can have severe impacts on calf productivity resulting in reduced profitability. Therefore, we sought to better understand anthelmintic resistance in Appalachia by surveying Angus bulls entering performance tests in VA and WV. During a four-year period, over 1050 Angus bulls were tested at bull development facilities in Wardensville, WV, Culpeper, VA, and Wytheville, VA. Fecal samples were collected at arrival and 14 days later for determination of fecal egg count (FEC) reduction. Upon arrival, all bulls received either fenbendazole (Wardensville, WV) or moxidectin (both VA tests). In Wardensville, treatment with albendazole had a 96.7% FEC reduction, whereas, treatment with moxidectin at Culpeper and Wytheville stations resulted in FEC reduction of 29% and 34.9%, respectively. Gain during these 14 days was significantly lower for bulls from Wytheville (0.87 kg/d) than those of Culpeper and Wardensville (1.87 and 2.1 kg/d; respectively). These data can be partially explained by higher bull FEC after treatment in Wytheville (101 eggs/g) compared to bulls in Wardensville and Culpeper (3.4 and 46.4 eggs/g respectively). Additionally, there was a negative correlation between delivery FEC and average daily gain. Taken together these data demonstrate resistance to moxidectin in bulls from the Appalachian region, and that elevated parasite infection may have contributed to reduced gain during the transition period.

PSXV-21 Assessment of the presence of anthelmintic resistance in Maryland beef cattle herds

Abstract Reduced anthelmintic efficacy in beef cattle has recently been documented at the national level. The objective of this study was to determine if anthelmintic resistance is present in Maryland beef cattle herds. For this study, the fecal egg count reduction (FECR) test was used to assess anthelmintic efficacy of composite samples. Between July and October 2020, anthelmintic efficacy was assessed for 17 groups of cattle across 14 individual farms in Maryland. Each test group consisted of 24 ± 6 calves or yearlings (&amp;lt; 16 months of age). Previous anthelmintic treatment history was used to assign each group to one of four commercially available anthelmintics: moxidectin (injectable), moxidectin (pour-on), doramectin, or fenbendazole. Prior to treatment, cattle were weighed to ensure appropriate dose according to the product label. Fecal samples were collected from all cattle within each group before and after (17 ± 5 d) treatment. Pre- and post-treatment samples were composited for each group on an equal-weight basis (10g per animal) and the number of eggs within the sample was determined using the 3-chambered McMaster technique. The mean FECR across all four anthelmintics was 60 ± 19% (mean ± 95% confidence interval), indicating that the anthelmintics tested in this study were largely ineffective. The FECR for the moxidectin injectable, moxidectin pour-on, doramectin, and fenbendazole treatments were 71 ± 38%, 47 ± 46%, 35 ± 88%, and 96 ± 18% (mean ± 95% confidence interval), respectively. Although these data indicate no statistically significant differences for efficacy among the four products tested, they do suggest that efficacy is highly variable across different anthelmintics and farms. Results also indicate that anthelmintic resistance exists on many cattle farms in Maryland. This study provides evidence that supports the need for more judicious anthelmintic use and alternative gastrointestinal parasite control measures in Maryland beef cattle herds.

A Survey of Control Strategies for Equine Small Strongyles in Lithuania.

SummaryAnthelmintic resistance (AR) in equine cyathostomins is being reported all over the world. In Lithuania, however, the last study on this subject was published more than fifteen years ago, thus little is known about the current situation. The aim of this study was to determine the factors that may associated with the development of AR on equine studs in Lithuania. A questionnaire containing seven open-ended and nine closed multiple-choice questions about worm control strategies, use of anthelmintic substances and stable management practices was posted to 71 randomly selected horse establishments in Lithuania. Replies were obtained from a total of 59 stables, representing 83 % of officially established stud farms in Lithuania.The results showed that more than 80 % of these establishments performed pasture management practices such as excrement removal from stables and pasture, 56 % mowed their pasture, 31 % practised mixed or rotational grazing with other species, and 97 % of the horses were routinely dewormed. Macrocyclic lactones (ML) (58 %, n=33) were the most commonly used drugs, followed by benzimidazoles (BZ) (24 %, n=14) and tetrahydropyrimidines (THP) (19 %, n=10). The majority of farms (60 %) treated horses four times per year and 68 % estimated the weight of the horses by eye before treatment. About 36 % of respondents had heard of faecal egg counts (FEC), but only 17 % used the test and as few as 9 % had tested their herds for AR with faecal egg count reduction tests (FECRT).The results demonstrate that there is scope for improving routines for worm control in many horse establishments in Lithuania. In order to increase knowledge and reduce the risk of the spread of AR, diagnostic methods should be adopted in a collaboration between stud farms and veterinary practitioners.

First Report of Anthelmintic Resistance in Gastrointestinal Nematodes in Goats in Romania.

Simple SummaryAnthelmintic resistance (AR) is a serious threat to animal health and has a major economic impact worldwide due to production and financial losses. Currently, there are three classes of anthelmintics most commonly used in small ruminants: the benzimidazoles (BZs), macrocyclic lactones (MLs) and cholinergic agonists (especially levamisole; LEV). The widespread use of those products has led to the emergence of drug-resistant parasite strains. In the present study, we describe for the first time a case of resistance to anthelmintics in goats in Romania. Resistance was detected and confirmed for two chemical groups of anthelmintics (MLs and BZs) by in vivo faecal egg count reduction test (FECRT) and in vitro methods: the egg hatch test (EHT) and larval development test (LDT). Considering the increasing prevalence of AR in goat herds in Europe and around the globe, we believe that the findings of our study on AR in goats in Romania do not represent a singular event and could hence be just the noticeable part of a much wider issue.Currently, there are three classes of anthelmintics most commonly used in small ruminants: the benzimidazoles (BZs), macrocyclic lactones (MLs) and cholinergic agonists (especially levamisole; LEV). The widespread use of those products has led to the emergence of drug-resistant parasite strains which represents a serious threat to the livestock industry. In the present study, we describe for the first time a case of resistance to anthelmintics in goats in Romania. The study was carried out in 2021 in a dairy goat herd from the Transylvania region. Two types of diagnostic methods were used to confirm anthelmintic resistance (AR). First, the faecal egg count reduction test (FECRT), an in vivo AR diagnostic method, was used to evaluate the efficacy of eprinomectin (EPM). The results of this test were analysed applying two different calculative methods that are used only in treated animals (without the control group). Furthermore, two in vitro methods were used: the egg hatch test (EHT) for the detection of resistance to BZs, and the larval development test (LDT) for detection of resistance to all three classes of anthelmintics. The results of FECRT indicate the resistance of gastrointestinal nematodes (GINs) to EPM in both calculative methods (FECR1 = −88% and FECR2 = −202%). In addition, the results obtained for ivermectin aglycone (IVM-AG) in LDT also indicate resistance to drugs from MLs group, especially avermectins. Similarly, the results of in vitro methods (EHT and LDT) indicate resistance to BZs in this herd. LEV was the only drug that stopped the development of L3 larvae 100% (LDT). H. contortus was the only nematode species found in coproculture after EPM treatment. Furthermore, H. contotus L3 larvae was the only species found in the wells with the highest concentrations of thiabendazole (TBZ) and IVM-AG in LDT. This suggests that resistance to both BZs and MLs was present for that species.

Anthelmintic activity of pomegranate peel extract (Punica granatum) and synthetic anthelmintics against gastrointestinal nematodes in cattle, sheep, goats, and buffalos: in vivo study.

Parasitic gastroenteritis (PGE) is one of the most important parasitic diseases that causes economic losses and health problems in ruminants. PGE causes a drop in milk, meat, and wool production in addition to decreasing animal fertility and sometimes leading to animal death. Conventional anthelmintics used for animal treatment are expensive, especially for farmers in developing countries. Moreover, the concern of anthelmintic resistance to these synthetic drugs is rising. Therefore, this study aimed to evaluate the anthelmintic activity of plant extract pomegranate (Punica granatum L) peel extract (PPE) against PGE infestations among ruminants. A total of 120 ruminants of different species (20 cattle, 12 buffalos, 68 sheep, and 20 goats) were examined for PGE eggs in their fecal samples. The animals under experiment were divided into four groups: the first group (negative control) was not given any drugs, the second group was given ivermectin (0.5ml/25kg bwt) (positive control 1), the third group was given albendazole (2.5mg active principle/kg bwt) (positive control 2), and the fourth group was given PPE (200mg/kg bwt). Fecal egg count (FEC) was performed on day 0 prior to the 1st dose of treatment. On day 15, an additional treatment (with the same doses) was administered and FEC was performed on days 7 and 21. Our results showed that on the 7th day of the experiment, there was an increase in FEC in the negative control group by 5%, while in the second, third, and fourth groups, there was a decrease in FEC with 95%, 90%, and 85% respectively. On the 21st day (7days from the second dose), there was an increase in FEC in the control group by a 10% and 100% reduction in FEC in both the second and third groups. While in the fourth group, there was a decrease in FEC by 97%. In conclusion, PPE could be used as a safe, cheap, and effective natural anthelmintic against PGE.

Therapeutic trial on clinical cases of impactive and spasmodic colic in donkeys in Gondar, northwest Ethiopia

The therapeutic trial was conducted from December 2018 to May 2019 to compare the therapeutic efficacy of different drug regimens in the treatment of impactive and spasmodic colic in donkeys in Gondar, Northwest Ethiopia. Twenty-five purposively selected donkeys were used in this study. Ten of them were showing suspected clinical signs of impactive colic and the remaining ten were with spasmodic colic. The rest five donkeys were kept as control group. For this trial, each disease category was again grouped into two subgroups. The first sub-group in group A with suspected spasmodic colic was treated with ivermectin and, the second sub-group was treated with fenbendazole. Similarly, the first subgroup in group B with suspected impactive colic was treated with meloxicam and the remaining sub-group was treated with hyoscine butyl bromide. Most vital parameters were recorded before and after treatment of colicky donkeys. Feces and blood samples were collected and examined pre and post-treatment from each donkey. Donkeys treated with ivermectin subcutaneously have 97.3% fecal egg count reduction percentage, whereas donkeys treated with fenbendazole orally have fecal egg count reduction percentage of 79.85%. Donkeys treated with meloxicam, most of the clinical signs disappear within 24 hours of time after treatment. Subcutaneous administration of ivermectin was effective for the treatment of spasmodic colic due to Strongyle infestation in donkeys. Therefore, field veterinarians should practice subcutaneous administration of ivermectin and intramuscular administration of meloxicam for effective treatment of spasmodic and impactive colic in donkeys, respectively.

Exploring the β-tubulin gene family in a benzimidazole-resistant Parascaris univalens population

Benzimidazole (BZ) drugs are frequently used to treat infections with the equine ascarid Parascaris univalens due to increasing resistance to macrocyclic lactones and pyrantel. Benzimidazole resistance is rare in ascarids in contrast to strongyle parasites where this resistance is widespread. In strongyles, single nucleotide polymorphisms (SNPs) at codons 167, 198 and 200 in a β-tubulin gene have been correlated to BZ resistance, but little is known about the β-tubulin genes and their possible involvement in BZ resistance in P. univalens and other ascarids. Previously two β-tubulin genes have been identified in P. univalens. In this study, we present five additional β-tubulin genes as well as the phylogenetic relationship of all seven genes to β-tubulins of other clade III and V nematodes. In addition, the efficacy of fenbendazole for treatment of P. univalens on a Swedish stud farm was studied in 2019 and 2020 using faecal egg count reduction test. Reductions varied from 73% to 88%, indicating the presence of a resistant P. univalens population on the farm. The emergence of BZ resistance emphasizes the need for development of molecular markers for rapid and more sensitive detection of resistant populations. We therefore investigated whether possible SNPs at positions 167, 198 or 200 in any of the β-tubulin genes could be used to distinguish between resistant and susceptible P. univalens populations. Amplicon sequencing covering the mutation sites 167, 198 and 200 in all seven β-tubulin genes revealed an absence of SNPs in both resistant and susceptible populations, suggesting that the mechanism behind BZ resistance in ascarids is different from that in strongyle nematodes and the search for a molecular marker for BZ resistance in P. univalens needs to continue.

MULTIDRUG RESISTANCE OF SHEEP GASTROINTESTINAL NEMATODES IN BAKRAJO DISTRICT, NORTH IRAQ TO ALBENDAZOLE, IVERMECTIN, AND LEVAMISOLE

A survey including 25 sheep farms in Bakrajo District, Sulaymaniyah, Iraq, was conducted to determine anthelmintic resistance (AR) against albendazole, ivermectin, and levamisole. Fecal Egg Count Reduction Test (FECRT) was used to accomplish this goal. Forty 6–24 month-old sheep of mixed sexes were selected from each farm and randomly divided into four groups. One group served as the untreated control, and the other groups orally administered the recommended doses of the tested drugs. Multidrug resistance against all three drugs was present in 8 of 25 farms (32%). Also, resistance to albendazole and ivermectin was detected on one farm. Albendazole was the most effective anthelmintic agent. Resistance to ivermectin was significantly higher than levamisole and albendazole. Larval cultures revealed that Trichostrongylus spp., Nematodirus spp., and Trichuris spp. were the prevalent gastrointestinal nematodes in the study area. The nematode genera were also detected in the posttreatment larval cultures. It is concluded that AR to albendazole, ivermectin, and levamisole is widespread in sheep in Bakrajo District, north Iraq. This resistance is mainly caused by the emergence of resistant Trichostrongylus and Nematodirus spp.

First Report of Multiple Drug-resistant Gastrointestinal Nematodes of Sheep in Arbat District, Sulaymaniyah, Iraq Detected By in Vivo and in Vitro Methods.

IntroductionThe control of gastrointestinal nematodes (GINs) in small ruminants is principally dependent on anthelmintic therapy, which encounters the rising problem of anthelmintic resistance (AR) development. Veterinarians reported anthelmintic failure in several sheep farms in Arbat District, Sulaymaniyah, northern Iraq, which called for a systematic study about the efficacy of three commonly used drugs: albendazole, ivermectin, and levamisole.Material and MethodsA faecal egg count reduction test (FECRT) was conducted to elucidate the anthelmintics’ efficacies, with coprocultures to determine the GINs parasitising sheep in the study area. Larval development assays (LDAs) were conducted to determine the drugs’ median inhibitory concentrations (IC50).ResultsThe FECRT revealed that AR was widespread to all three drugs, and ivermectin was the least effective, reducing the faecal egg counts (FECs) by 50.5% to 57.1%. The coprocultures revealed that the GIN genera of sheep in Arbat District were Trichostrongylus, Nematodirus, and Trichuris, and the resistance was mainly due to Trichostrongylus species. The mean IC50 of albendazole, ivermectin, and levamisole were 0.073 ng/mL, 7.97 ng/mL, and 1.43 ng/mL, respectively.ConclusionThis study is the first Iraqi report of AR confirmed by both in vivo FECRT and in vitro LDA methods.