Abstract
Globally, gastrointestinal nematodes (GIN) have a considerable impact on the livestock husbandry and health conditions in Iran and throughout the world. The infected animals with gastrointestinal nematodes mostly need anthelmintic therapy which leads to the development of anthelmintic drug resistance. The main objective of the current study was to determine the frequency of β-tubulin isotype 1 gene polymorphism to albendazole (Alb) in Teladorsagia circumcincta isolated from sheep abomasum in Urmia city, Iran. A total number of 140 sheep abomasa were randomly collected and 157 infected abomasa with T. circumcincta were found. Alb resistance in T. circumcincta determined using Allele-Specific PCR (ASP) technique. The frequency of the homozygous susceptible (SS), homozygous resistant (rr) and heterozygous susceptible (Sr) to Alb were 51.7%, 6.9% and 41.4% in the examined T. circumcincta, respectively. It was concluded that Alb-resistance alleles were widespread in examined T. circumcincta which prevention control program should be lunched in the region.