<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Cases of parasite resistance to the main classes of anthelmintics are increasingly reported from small ruminants at farms in Europe. We visited a goat farm in Slovakia in November 2019 with suspected parasite problems that reduced productivity and performed an <italic>in vivo</italic> faecal egg count reduction test (FECRT) and an <italic>in vitro</italic> larval development test (LDT) for all three main classes of anthelmintics. The lowest efficacy (60 %) detected by FECRT was for ivermectin (IVM). Benzimidazole (BZ) efficacy ranged between 80.3 and 86.5 %, and levamisole (LEV) efficacy was 94 %. The results from the <italic>in vivo</italic> FECRT test were confirmed by the <italic>in vitro</italic> LDT. Minimum inhibitory concentration (MIC) 173.6 ng/ml for IVM several times exceeded the recommended threshold of 21.6 ng/ml. Mean LD<sub>50</sub> for BZ was equal to the threshold concentration, but the other threshold criteria indicated a low level of resistance in the population. The LDT did not indicate the presence of resistance only for LEV. The MIC 1.0 μg/ml for LEV was evaluated as susceptible with respect to species composition. <italic>Teladorsagia</italic> was the dominant genus after treatment with BZ, IVM, and LEV. <italic>Haemonchus contortus</italic> was identifi ed after treatment with BZ and LEV.</p></abstract>

Cases of parasite resistance to the main classes of anthelmintics are increasingly reported from small ruminants at farms in Europe. We visited a goat farm in Slovakia in November 2019 with suspected parasite problems that reduced productivity and performed an in vivo faecal egg count reduction test (FECRT) and an in vitro larval development test (LDT) for all three main classes of anthelmintics. The lowest efficacy (60 %) detected by FECRT was for ivermectin (IVM). Benzimidazole (BZ) efficacy ranged between 80.3 and 86.5 %, and levamisole (LEV) efficacy was 94 %. The results from the in vivo FECRT test were confirmed by the in vitro LDT. Minimum inhibitory concentration (MIC) 173.6 ng/ml for IVM several times exceeded the recommended threshold of 21.6 ng/ml. Mean LD50 for BZ was equal to the threshold concentration, but the other threshold criteria indicated a low level of resistance in the population. The LDT did not indicate the presence of resistance only for LEV. The MIC 1.0 μg/ml for LEV was evaluated as susceptible with respect to species composition. Teladorsagia was the dominant genus after treatment with BZ, IVM, and LEV. Haemonchus contortus was identifi ed after treatment with BZ and LEV.

Multiple anthelmintic resistance at a goat farm in Slovakia

Helminthologia

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

{"article-title":"Multiple anthelmintic resistance at a goat farm in Slovakia"}

Cases of parasite resistance to the main classes of anthelmintics are increasingly reported from small ruminants at farms in Europe. We visited a goat farm in...

Method of calculation	FECR (%)
Method of calculation	BZ group	IVM group	LEV group
Cabaret and Berrag (2004)	80.3	59.0	94.2
Kochapakdee (1995)	86.5	60.4	94.0

LD₅₀ ± SD	MIC	MIC
BZ group	IVM group	LEV group
(μg/ml)	(ng/ml)	(μg/ml)
0.020 ± 0.0007	173.6	1.0

Before treatment (%)		After treatment (%)
Nematode	%	Nematode	BZ group	IVM group	LEV group
Teladorsagia	45	Teladorsagia	79	100	91
Haemonchus contortus	17	Haemonchus contortus	21	–	9
Oesophagostomum/Chabertia ovina	19	Oesophagostomum/Chabertia ovina	–	–	–
Trichostrongylus	19	Trichostrongylus	–	–	–

Multiple anthelmintic resistance at a goat farm in Slovakia

Published Online: Jun 08, 2021

Page range: 173 - 178

Received: Sep 18, 2020

Accepted: Dec 04, 2020

DOI: https://doi.org/10.2478/helm-2021-0014

Keywords
Small ruminants, anthelmintic resistance, ivermectin, benzimidazole, spp,

© 2021 M. Babják, A. Königová, M. Várady, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Results of the in vivo FECRT: percent reduction 10 days after treatment.

Values of LD50 and MIC from the LDT for each group of goats.

Results of the morphological identification of L3 larvae before and after treatment.

Multiple anthelmintic resistance at a goat farm in Slovakia

Published Online: Jun 08, 2021

Page range: 173 - 178

Received: Sep 18, 2020

Accepted: Dec 04, 2020

DOI: https://doi.org/10.2478/helm-2021-0014

KeywordsSmall ruminants, anthelmintic resistance, ivermectin, benzimidazole, spp,

© 2021 M. Babják, A. Königová, M. Várady, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Results of the in vivo FECRT: percent reduction 10 days after treatment.

Values of LD50 and MIC from the LDT for each group of goats.

Results of the morphological identification of L3 larvae before and after treatment.

Keywords
Small ruminants, anthelmintic resistance, ivermectin, benzimidazole, spp,