Parasite study sheds light on anthelmintic resistance
The barber pole worm is resistant to major anthelmintics
A new study of the barber pole worm has offered insights into how treatments work and why anthelmintic resistance may occur.
Barber pole worm, or Haemonchus contortus, is a parasitic worm that lives in the gut of sheep and other livestock worldwide, and is now resistant to all major anthelmintics.
To find out how and why resistance has occurred, the research team studied a strain of H contortus that is susceptible to all major treatments for parasitic worms.
Scientists identified five enzymes key to the survival of the barber pole worm, two of which are already being studied as potential drug targets – one against another type of worm, the other against Mycobacterium tuberculosis.
According to funding institute the Wellcome Trust, the barber pole worm is endemic on all UK farms and is a significant threat to global food security. It is estimated to cost the UK sheep industry more than £80 million each year.
"Getting to grips with genomes such as that of H contortus is our best option to tackle the issue of drug resistance and develop new drugs against parasitic worms," said Professor Neil Sargison, study author from the University of Edinburgh's Royal (Dick) School of Veterinary Studies.
The research team also identified a set of genes that were more active within the parasite's gut, and at certain stages of its life cycle. It is hoped this information will offer a source of potential drug and vaccine candidates.
Co-author Professor Jon Gilleard, of the University of Calgary, said: "Not only is this worm closely related to many other parasites of livestock it is also similar to some species of worms in humans.
"This makes it an extremely important model parasite species for experimental studies. Revealing new drug targets against H contortus could provide much-needed new treatment opportunities against parasitic worms in both animals and humans."
The BSAVA has opened submissions for the BSAVA Clinical Research Abstracts 2026.
