Faculty of Veterinary Medicine, Urmia University Veterinary Research Forum 2008-8140 15 4 2024 04 01 Evaluation of drug resistance to albendazole and levamisole against lung worms in goat flocks based on fecal larvae count reduction test 181 186 709161 10.30466/vrf.2023.2010062.3991 EN Sepideh Abdollahzadeh Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran Mousa Tavassoli Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran 0000-0002-0169-6041 Bijan Esmaeilnejad Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran 0000-0003-1781-5890 Ghader Jalilzadeh-Amin Department of Internal Medicine and Clinical Pathology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran 0000-0003-2869-5492 Journal Article 2023 08 26 The over-use of anti-parasitic compounds as a method of control has led to insufficient effectiveness and widespread drug resistance worldwide. The aim of this study was to investigate the efficacy of albendazole and levamisole as anti-parasitic agents in a lung worm control program in goat flocks. During 2021 and 2022, a total of 110 goats (age of four months and above) were randomly selected from 11 herds in the north-western region of Iran including Saanen breed (both sexes of the same age). The results indicated that 3.60, 50.80 and 41.90% were respectively infected with <em>Dictyocaulus filaria</em>, <em>Muellerius capillaris </em>and <em>Proto-strongylus rufescens</em>, and generally all the lung parasites in goats of this region were resistant to albendazole and levamisole. Due to clinical importance of <em>D. filaria</em> in goats, the molecular analysis of two samples was also done. Sequencing results showed that the identified parasites were 100% similar to the reference sequences registered in the GenBank<sup>®</sup>. The results of this research showed low level of these anthelmintics efficacy against <em>Dictyocaulus </em>and <em>Muellerius</em>. Generally, the lung parasites in goats of this region are resistant to albendazole and levamisole. The <em>P. rufescens </em>showed high resistance to these drugs. Totally, it can be concluded that the level of drug resistance varies in different parts of the world; but, the frequencies of drug resistance in different parts of the world are not the same, requiring more studies. Albendazole Drug resistance Fecal larvae count reduction test Levamisole Lung worm https://vrf.iranjournals.ir/article_709161_4c9fa15e11e3b8c367b2a0fe7ed3c9fb.pdf