scholarly journals Increasing resistance to multiple anthelmintic classes in nematodes including Haemonchus contortus on sheep farms in Southwest England.

Author(s):  
K Bull ◽  
M. J. Glover ◽  
H. Rose Vineer ◽  
E. R. Morgan

Abstract Background: Anthelmintic 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. Methods: Faecal 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 (PNA) staining and used to estimate faecal egg count reduction percentages (FECR%) using the egg Counts R package. Results: On 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. Haemonchus 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 was observed in this species to all anthelmintics tested, on different farms. Conclusion: The results demonstrate diversity of AR profiles on farms, progression of anthelmintic resistance 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.

2016 ◽  
Vol 88 (1) ◽  
pp. 397-402 ◽  
Author(s):  
Carlos M.B. Gárcia ◽  
Lew K. Sprenger ◽  
Efraín B. Ortiz ◽  
Marcelo B. Molento

This study aimed to report the presence of parasites resistant to the most used anthelmintic drugs in sheep in Colombia. Four farms (denominated farm 1, 2, 3 and 4) were selected where the animals were not treated with anthelmintics for two months before the trial. Animals with faecal egg count (FEC) above 150 and of different ages were allocated into six groups, each consisting of at least 5 animals. The drugs and dosages used were: ivermectin 1% (0.2 mg/kg), albendazole 25% (5 mg/kg), fenbendazole 10% (5 mg/kg), levamisole 10% (5 mg/kg), and moxidectin 1% (0.2 mg/kg). Anthelmintic efficacy was determined by the FEC reduction test (FECRT) with a second sampling 14 days post-treatment. The efficacy of albendazole and fenbendazole at farm 1 was above 95%, which was different from the others farms. The FECRT indicated the presence of multidrug resistance in the other farms where no tested drugs showed activity higher than 79% (albendazole: 0 to 55%, fenbendazole: 51.4 to 76.6%, ivermectin: 67.3 to 93.1%, levamisole: 0 to 78.1%, and moxidectin: 49.2 to 64.1%).Haemonchus contortus was the predominant (96%) species, followed by a small presence of Trichostrongylus sp. (3%) andCooperia sp. (1%). Therefore, we report for the first time the existence of multiple anthelmintic resistance in gastrointestinal nematodes of sheep in Colombia.


Author(s):  
Noorzaid Muhamad ◽  
Syahirah Sazeli ◽  
Resni Mona ◽  
Jannathul Firdous

The anthelmintic resistance has limited the control of gastrointestinal nematodes of small ruminants and thus has awakened interest in the study of plants extract as a source of anthelmintics. These experiments were carried out to evaluate the in vitro efficacy of Jatrophacurcas latex extract against Haemonchuscontortus larval motility. To evaluate the larvicidal activity, H.contortus L3 were incubated with the extracts with varying concentration of 5 mg/mL, 10 mg/mL, 15 mg/mL and 20 mg/mL at 27°C for 48, 72 and 96 hrs. The results were subjected to the Kruskal-Wallis test (P less than 0.05). The extracts showed dose-dependent larvicidal effects. These results suggest that J.curcas can be used to control gastrointestinal nematodes of small ruminants.


2018 ◽  
Vol 7 (2) ◽  
pp. 111-115
Author(s):  
JK Muthee ◽  

The use of plants, or their extracts, for the treatment of human and animal ailments, including helminthosis is steeped in antiquity. Anthelmintic resistance in pathogenic helminths has been spreading in prevalence and severity to a point where there is multi-drug resistance against the three major classes of anthelmintics. This globe-wide phenomenon calls for urgent search for different approaches to the control of helminthosis including novel anthelmintic products. The objective of this study was to evaluate the efficacy of plants, which are commonly used in the treatment and control of helminthosis, under the natural grazing conditions in Loitoktok Sub-County of Kenya. The plant species (Albizia anthelmintica, Myrsine africana, and Embelia schimperi were selected based on their availability and ethnopharmacological uses, as anthelmintics, by the traditional health practitioners in the area. Fifty sheep of mixed breeds, belonging to local herders, and naturally infected with mixed gastrointestinal nematodes were recruited for the study. The herbal remedies were prepared and administered by methods prescribed by the traditional practitioners. Their efficacy was determined using faecal egg count reduction test (FECRT). The percentage faecal egg count reduction against the mixed gastrointestinal nematodes was 59, -11, -31 and 87 for Myrsine africana, A. anthelmintica, E. schimperi and albendazole respectively. It was concluded that some of the remedies have some efficacy and further studies are needed to evaluate their potential as anthelmintics. There was also suspicion of development of anthemintic resistance to albendazole and herders needed to be advised accordingly on the proper use of conventional anthelmintic products


2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 73-73
Author(s):  
Joan M Burke ◽  
James E Miller ◽  
Mohan Acharya ◽  
Erin Wood

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.


2016 ◽  
Vol 53 (1) ◽  
pp. 24-30 ◽  
Author(s):  
T. Kupčinskas ◽  
I. Stadalienė ◽  
A. Šalomskas ◽  
P. Trusevičius ◽  
M. Varady ◽  
...  

SummaryThis study determined the prevalence of anthelmintic resistance (AR) in parasitic nematodes on smallholder sheep farms in Lithuania from April to November 2014. Faecal samples were collected from two groups of 10-15 sheep treated with fenbendazole (FBZ) or ivermectin (IVM) on 18 sheep farms. Two samples were collected from each group: on day zero (T1) and 10-14 days after treatment. Faecal egg counts (eggs per gramme, EPG) were determined using a modified McMaster technique. Animals with < 140 EPG on day zero were removed from the analysis. The prevalence of AR was estimated using the in vivo faecal egg count reduction test. AR to FBZ was detected on three of 15 farms where FBZ was used (20 %) and was suspected on one farm (6.7 %). AR to IVM was detected on two of 16 farms where IVM was used (12.5 %). The main species of resistant gastrointestinal nematodes (GINs) identified after treatment were Teladorsagia spp. and Trichostrongylus spp. A questionnaire surveying 71 sheep farmers estimated that 71.8 % of sheep farmers used anthelmintics against GINs. IVM was the most frequently (68.6 %) applied anthelmintic, and 62.7 % of the respondents reported treating their animals twice a year. This study confirmed the presence of AR to GIN infections on sheep farms in Lithuania. Future studies should assess the prevalence of AR to GIN infection using in vitro methods.


2017 ◽  
Vol 62 (4) ◽  
Author(s):  
Tianlong Han ◽  
Min Wang ◽  
Guanghe Zhang ◽  
Dongsheng Han ◽  
Xinwei Li ◽  
...  

AbstractGastrointestinal nematodes (GIN) are a crucial restraint to grazing sheep production worldwide. This study was conducted to determine the infections and anthelmintic resistance (AR) of GIN in pasture-based sheep in the Eastern Inner Mongolia, China. GIN eggs were tested from 600 grazing sheep feces of 10 farms using saturated saline flotation method and McMaster’s method. The egg hatch test (EHT) and the faecal egg count reduction test (FECRT) were used to evaluate resistance of GIN to anthelmintics. We found that the average infection rate was 79.2% (range: 45%-100%). The grand mean faecal egg count (FEC) was 1813.2 eggs per gram (EPG) (range: 0-32400 EPG). There were significant differences in GIN infection among different breeds of sheep. The sequence of infection intensity and infection rate were Small fat tail > Ujimqin > Ju Ud (


2014 ◽  
Vol 23 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Víctor Humberto Suarez ◽  
Silvina Lujan Cristel

Risk factors for anthelmintic resistance (AR) on bovine ranches were studied. Data were derived from a survey made to 50 ranch owners, who had conducted a faecal egg-count-reduction test. The questionnaire contained descriptors of bovine ranch management and nematode control. A case-control design study was undertaken and AR cases were present in 26 herds. Associations between the binary outcome variable (AR versus not AR) and risk factors recorded in the questionnaire were evaluated. Variables associated with the presence of AR at P< 0.15 and/or odds ratio (OR) > 2 were subjected to a multivariable logistic regression model. The main effects contributing to general AR (avermectin AVM and/or benzimidazole) in the final model were total number of annual treatments (OR 7.68; 95% CI 2.4 to 28.3) and use of more than 75% of AVM in the past (OR= 18.6; 95% CI 1.3 to 97.3), whereas for AVM resistance alone were total number of AVM annual treatments (OR= 11.5; 95% CI 2.9 to 45.5) and number of AVM Nov-Jan treatments (OR= 5.8; 95% CI 1.71 to 47.9). The results showed that treatment frequency, date of treatment and frequency of treatment in the past with a single drug were the main risk factors involved in AR development.


2020 ◽  
Vol 50 (11) ◽  
Author(s):  
Vanessa Diniz Vieira ◽  
Franklin Riet Correa ◽  
Vinícius Longo Ribeiro Vilela ◽  
Márcia Alves de Medeiros ◽  
Jouberdan Aurino Batista ◽  
...  

ABSTRACT: This study aimed to determine control measures for gastrointestinal nematodes in goats in the northeastern semiarid after analyzing the dynamics of gastrointestinal helminths during the drought, the evolution of the parasitic load after the first rains and the differences in susceptibility between goats of different categories and ages. Five farms were studied from March 2013 to January 2015. Feces were collected from all goats every month, for fecal egg counts (FECs). No treatment was required on any farm during the dry period. In 2013, with annual rainfall of 265-533 mm, treatments were not necessary during the rainy season. However, in 2014, with rainfall of 604-778 mm, treatments were necessary 60-90 days, after the first rains. On three farms, gastrointestinal nematodes showed multiple anthelmintic resistance. The FECs from lactating goats were significantly higher than from dry and young goats. In conclusion, in the Brazilian semi-arid region (Caatinga biome), it is generally unnecessary to treat grazing goats during the dry season. In the rainy season, the parasite load increases 2-3 months after the first rains. In both, the dry and the rainy season, farmers should monitor their herds by means of FEC or another criterion (anemia or submandibular edema), to determine the need to treat.


2020 ◽  
Vol 94 ◽  
Author(s):  
A. Cruz-Tamayo ◽  
R. González-Garduño ◽  
G. Torres-Hernández ◽  
C. Becerril-Pérez ◽  
O. Hernández-Mendo ◽  
...  

Abstract The objective of this study was to evaluate the reduction in nematode faecal egg count (FEC) in Pelibuey lambs segregated as resistant (RES), susceptible (SUS) and intermediate (INT) to gastrointestinal nematodes. Twenty-nine weaned Pelibuey lambs, aged five months old, free of nematode infection, were used. Nine lambs were RES, six were SUS and 14 were INT lambs. The study consisted of two phases: in Phase 1 the lambs were infected experimentally with Haemonchus contortus. In Phase 2, the lambs were naturally infected by grazing. Faecal and blood samples were taken every week. The packed cell volume and total protein were quantified. The FEC value (FECmax) per lamb was recorded together with a natural reduction in FEC in the two phases. The data were analysed with a model of measures repeated over time. During Phase 1, the RES lambs showed the lowest FEC (1061 ± 1053) compared to the other groups (INT: 2385 ± 1794 eggs per gram of faeces (EPG); and SUS: 3958 ± 3037 EPG). However, in Phase 2 no significant differences (p > 0.05) were observed between the groups of lambs (RES: 275 ± 498 EPG; SUS: 504 ± 1036 EPG; and INT: 603 ± 1061 EPG). At the end of Phase 1, the FEC of RES lambs was naturally reduced by 75.5% in respect to FECmax (p < 0.05), and at the end of Phase 2 the reduction in FEC was 90% in respect to FECmax (p > 0.05); the same behaviour was observed in RES and SUS lambs. It is concluded that the artificial infection in the lambs induced a more rapid immune response in RES than SUS lambs, and all lambs developed high acquired resistance by continuous infection.


2019 ◽  
Vol 6 (1) ◽  
pp. e000332 ◽  
Author(s):  
Christian Lambertz ◽  
Ioanna Poulopoulou ◽  
Kunlayaphat Wuthijaree ◽  
Matthias Gauly

Anthelmintic resistance (AR) in sheep raised under mountain farming conditions in South Tyrol (Northern Italy) was assessed on eight farms (n=99 animals). A faecal egg count reduction (FECR) test was done after routine anthelmintic treatments. Furthermore, on 27 farms (n=306 animals), a FECR test was conducted after oral formulations of a macrocyclic lactone (ML), benzimidazole (BZ) (partly in combination with salicylanilide (SA)) or a combination of imidazothiazole and SA were applied under controlled conditions on the same farm. Following routine treatments, three of five ML-treated flocks showed an adequate efficacy, while the other two reached a FECR of only around 75 per cent. A wide range of gastrointestinal nematode genera were identified in one flock following the treatment. From the three BZ-treated flocks, only one showed an adequate FECR, both other farms reached 68 per cent and 84 per cent, respectively. Under controlled conditions, FECR ranged between 77 per cent and 81 per cent indicating AR for all the applied anthelmintics. Trichostrongylus species, Teladorsagia species and Haemonchus species were identified after ML treatment, Teladorsagia species after BZ treatment and Trichostrongylus species and Haemonchus species after combined BZ and SA application. Taking into consideration that underdosing might have affected results of the routine treatments, a high prevalence of AR was found in sheep under mountain farming conditions.


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