Evaluation of drug resistance to albendazole and levamisole against lung worms in goat flocks based on fecal larvae count reduction test

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 ۲۰۲۱ and ۲۰۲۲, a total of ۱۱۰ goats (age of four months and above) were randomly selected from ۱۱ herds in the north-western region of Iran including Saanen breed (both sexes of the same age). The results indicated that ۳.۶۰, ۵۰.۸۰ and ۴۱.۹۰% were respectively infected with Dictyocaulus filaria, Muellerius capillaris and Proto-strongylus rufescens, and generally all the lung parasites in goats of this region were resistant to albendazole and levamisole. Due to clinical importance of D. filaria in goats, the molecular analysis of two samples was also done. Sequencing results showed that the identified parasites were ۱۰۰% similar to the reference sequences registered in the GenBank®. The results of this research showed low level of these anthelmintics efficacy against Dictyocaulus and Muellerius. Generally, the lung parasites in goats of this region are resistant to albendazole and levamisole. The P. rufescens 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.

Keywords:

Albendazole , Drug resistance , Fecal larvae count reduction test , Levamisole , Lung worm