Background: Haemonchosis is a major parasitic infestation in ruminant livestock, causing significant economic losses annually. The causative organisms are helminths of the genus spp. Detection of the causative agent is important for effective management and control of the disease. Molecular detection and characterization of parasites is a very dependable approach for parasite identification, especially where morphological characterization is unreliable. Methods: To detect and characterize in cases of haemonchosis at a Municipal abattoir in Ibadan, Nigeria; abomasal samples were collected from cattle at the abattoir. Polymerase chain reaction (PCR) was used to detect and amplify 320 bp internal transcribed spacer-2 () and 400 bp external transcribed spacer (ETS) genes of the adult worms in the samples. Multiple sequence alignment and phylogenetic tree reconstruction were carried out to further confirm the presence of the worms. Results: PCR, multiple sequence alignment, and phylogenetic reconstruction confirmed the presence of in the abomasal samples and further confirmed the species as a distinct species of bovine worms at the abattoir. Multiple sequence alignment also revealed genetic sites that can be employed to distinguish from and . Conclusion: Molecular techniques; PCR and sequence analysis are very important and reliable in the diagnosis of parasitic diseases. This will help to formulate effective control measures for eradication of the parasite.
