Haemonchus contortus is a gastro-intestinal parasite. The parasites were collected from the abomasum of 30 slaughtered goats from a local slaughterhouse in Cha-am District, Phetchaburi Province, Thailand. Co-infection of H. contortus and H. placei was found in 24 goats. The prevalence of H. contortus was 80% while H. placei was 86. 67% . This study determined the genetic variation using 20 H. contortus samples for amplification and sequencing that used the internaltranscribed spacer-2 (ITS-2) and nicotine amide dehydrogenase subunit 4 (nd4) gene. The nucleotide sequence analysis revealed 9 genotypes (ITS-2) and 19 haplotypes (nd4) among 20 and 19 samples, respectively. Phylogenetic tree analysis using both ITS-2 and nd4 sequences showed a close relationship within the H. contortus population in this area. Since haemonchosis in goats is still a serious problem which causes economic losses, knowledge on the genetic variation of H. contortus in Thailand may have implications for epidemiology and further parasite control programs.
