Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Dec 19;67(4):575-581.
doi: 10.2478/jvetres-2023-0057. eCollection 2023 Dec.

Multidrug resistance in Haemonchus contortus in sheep - can it be overcome?

Michal Babják  1 , Alžbeta Königová  1 , Michaela Komáromyová  1 , Tetiana Kuzmina  1   2 , Pawel Nosal  3 , Marián Várady  1
Affiliations

Multidrug resistance in Haemonchus contortus in sheep - can it be overcome?

Michal Babják et al. J Vet Res. .

Abstract

Introduction: Gastrointestinal nematodes pose a threat to animal health and affect farmers by negatively impacting farm management.

Material and methods: The study was conducted on a sheep farm with suspected reductions in the efficacies of anthelmintics. Efficacy was determined using in vivo faecal egg count reduction, in vitro egg hatch (EHT) and larval development (LDT) tests. In the first phase, 60 sheep were equally split into six groups. Group 1 received the recommended dose of albendazole (ALB), group 2 received the same after fasting for 24 h, group 3 received the dose divided into two halves at 6 h intervals, group 4 received a double dose of ALB, and group 5 received the recommended dose of ivermectin (IVM). Group 6 served as a control. The second phase of the experiment had two groups: one treated with levamisole (LEV) and a control group. Faecal samples were collected from all sheep.

Results: No reduction of egg output was observed in the groups treated with single, double, or divided doses of ALB, but one of 13.7-16.9% was noted in the fasting group. Efficacy in the IVM group ranged from 31.50 to 39.97%. The mean concentrations sufficient to prevent 50% of the eggs from hatching in the in vitro EHT and the mean concentrations in which the development of larvae to the L3 stage was inhibited by 50% in the LDT exceeded established thresholds for benzimidazoles and IVM. Haemonchus contortus was the only species identified after treatment. The LDT did not indicate the presence of resistance to LEV. All animals treated with LEV were negative for eggs 10 d after treatment.

Conclusion: Resistance to ALB and IVM in Haemonchus contortus was confirmed. Alternative approaches to improve the efficacies of benzimidazole did not sufficiently increase the efficacy, but LEV was an efficient anthelmintic treatment.

Keywords: Haemonchus contortus; alternative treatment; drug resistance; levamisole; sheep.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interests Statement: The authors declare there is no conflict of interests regarding the publication of this article.

References

    1. Ali D.N.,, Hennessy D.R The effect of level of feed intake on the pharmacokinetic disposition and efficacy of ivermectin in sheep J Vet Pharmacol Ther. 1996;19:89. doi: 10.1111/j.1365-2885.1996.tb00018.x. .: . , , –. , doi: . - DOI - PubMed
    1. Babják M.,, Königová A.,, Urda-Dolinská M.,, Vadlejch J.,, Várady M Anthelmintic resistance in goat herds – in vivo versus in vitro detection methods Vet Parasitol. 2018;254:10. doi: 10.1016/j.vetpar.2018.02.036. .: . , , –. , doi: . - DOI - PubMed
    1. Babják M.,, Königová A.,, Várady M Multiple anthelmintic resistance at a goat farm in Slovakia Helminthologia. 2021;58:173. doi: 10.2478/helm-2021-0014. .: . , , –. , doi: . - DOI - PMC - PubMed
    1. Bordes L.,, Dumont N.,, Lespine A.,, Souil E.,, Sutra J.F.,, Prévot F.,, Grisez C.,, Romanos L.,, Dailledouze A.,, Jacquiet P First report of multiple resistance to eprinomectin and benzimidazole in Haemonchus contortus on a dairy goat farm in France Parasitol Int. 2020;76:102063 doi: 10.1016/j.parint.2020.102063. .: . , , , doi: . - DOI - PubMed
    1. Cabaret J.,, Berrag B Faecal egg count reduction test for assessing anthelmintic efficacy: average versus individually based estimations Vet Parasitol. 2004;121:105. doi: 10.1016/j.vetpar.2004.01.020. .: . , , –. , doi: . - DOI - PubMed

LinkOut - more resources