New guidelines released by the Australian Equine Parasitology Advisory Panel (AEPAP) will help vets better manage internal parasites in horses, providing information about common parasites, how to control them, and how to test for drug resistance – a growing problem affecting the $1.65 billion a year Australian Thoroughbred industry.
Led by Professor Abdul Jabbar from the Melbourne Veterinary School at the University of Melbourne the Australian Guidelines for Equine Internal Parasite Management (AGEIPM) offer best-practice recommendations to combat drug resistance in horse parasites.
Tailored for specialist equine veterinarians, the guidelines are grounded in locally conducted scientific research, provide information on target parasites and risk factors for their transmission, as well as practical advice on surveillance, antiparasitic drug choice, timing of treatment, and drug resistance testing.
“Parasites such as roundworms and small redworms are ubiquitous in horses and can present a significant concern to animal health and welfare, particularly in foals and yearlings,” Professor Jabbar explains.
Large roundworms (Parascaris spp.) present in the stomach of a Thoroughbred filly after post mortem conducted at the Melbourne Veterinary School, University of Melbourne (Picture: Ghazanfar Abbas/Supplied)
“Since the introduction of synthetic drugs against parasites in the 1960s, control of horse parasites in Australia has heavily relied upon interval-based treatments.
“Unfortunately, this has led to the emergence of resistant parasite populations for almost all currently available antiparasitic drugs targeting intestinal parasites.
“Until now there have been no Australian standard guidelines on using antiparasitics in horses across various climatic zones, nor recommendations on best parasite control practices in horses,” he says.
The new guidelines have been formulated using data collected through extensive analysis on Australian Thoroughbred horse farms as part of graduate research by University of Melbourne PhD student Dr Ghazanfar Abbas.
Ghazanfar Abbas (then a doctoral student) collecting faecal samples in the field. Picture: Ghazanfar Abbas/Supplied).
“Co-funded by AgriFutures Australia, Thoroughbred Breeders Australia and Boehringer Ingelheim, the AGEIPM will help reduce reliance on blanket use of drugs in equine parasite management programs and help curb progression of resistance to the limited antiparasitic drug classes available for treating horses,” Professor Jabbar says.
“It’s important that approaches to worm control in horses change, and that practices are based on science, not tradition.
“In addition, targeted treatment protocols will reduce the risk of dewormer resistance spilling over into other livestock industries.”
Co-researcher with Professor Jabbar on the AGEIPM Dr Anne Beasley from the University of Queensland says to slow the further development of antiparasitic resistance, regular monitoring of parasite burdens should guide when to administer antiparasitics and the choice of drug class, while the efficacy of antiparasitic drugs should be tested regularly.
“Combined with non-chemical strategies to disrupt parasite life cycles, these tools can be integrated into a comprehensive management approach,” Dr Beasley says.
Key messages for the equine industry are that there is a critical need to:
- Develop case studies to demonstrate the benefits of evidence-based worm control in horses
- Develop training modules and online resources for farm managers, farm workers and veterinarians
- Assess the utility and uptake of point-of-care diagnostic (ie on-farm) methods for monitoring parasite burdens and antiparasitic drug resistance to demonstrate how improved diagnostic methods can contribute to better parasite control practices
- Assess the efficacy of a biological worm control product (such as BioWorma®) against intestinal parasites in various climatic zones of Australia to reduce the reliance on antiparasitics
- Advance research towards developing a vaccine against parasites (ie roundworms) in foals and weanlings
- Demonstrate the practical application of integrated parasite management (combining chemical and non-chemical approaches) in horse populations using demonstration sites/case studies in various regions/climates of Australia
- Establish a central facility dedicated to routine parasite testing for the horse industry
- Develop concise, pocket-sized guidelines for parasite control to enhance accessibility and implementation.
Funding
AgriFutures Australia, Thoroughbred Breeders Australia and Boehringer Ingelheim, Australia supported this work. The funding partners did not have any role in the design or content of the study.
The PhD student, Ghazanfar Abbas, is a grateful recipient of the Australian Government Research Training Scholarship through the University of Melbourne.
Declaration of competing interest
The authors of this article are members of the Australian Equine Parasitology Advisory Panel (AEPAP), including Abdul Jabbar, Ghazanfar Abbas, Jenni Bauquier, Charles El-Hage, Abdul Ghafar and Ian Beveridge (The University of Melbourne), Anne Beasley (University of Queensland), Kristopher Hughes (Charles Sturt University), Caroline Jacobson and Emma McConnell (Murdoch University), Edwina Wilkes (Racing Victoria), Peter Carrigan and Lucy Cudmore (Scone Equine Hospital) and John Hurley (Swettenham Stud). Boehringer Ingelheim supported the panel.
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported here.
Acknowledgements
The researchers thank the managers and staff, breeders and veterinarians of the Thoroughbred industry across Australia for their help and cooperation in collecting faecal samples.
First published on 24 January 2025.
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