Anthelmintic Resistance in Australian Horses

Anthelmintic Resistance in Australian Horses: What You Need to Know (Last 5 Years)

Worm resistance is no longer just a theory — it's a growing reality in Aussie horses. Pictured is a breakdown of how the main worming drugs are holding up

What Can YOU Do?

FECRT (Faecal Egg Count Reduction Test)

→ Run at least once per year to check if your wormer is still working.

→ Especially important if you're worming based on egg counts.

Track ERP (Egg Reappearance Period):

Shortened ERP = early warning of resistance.

Moxidectin: Should last ~12 weeks

→ If eggs reappear <5 weeks = Alarming

Ivermectin: ERP ~8 weeks

Key Takeaways (Australia-specific):

• Moxidectin resistance is emerging – especially in racehorses & studs

• Benzimidazoles are largely ineffective for strongyles

• Ascarids in foals are commonly resistant to ivermectin

• FEC testing + pasture management = essential tools to preserve wormer effectiveness

Learn more here:

https://parasitesandvectors.biomedcentral.com/.../s13071...

Worm smarter, not harder.

If you’re unsure whether your wormer is still doing its job — it’s time to test.

Got questions about FECRT or resistance? Pop them below or message me

Reference: Macdonald, S.L., Abbas, G., Ghafar, A., et al. (2023). Egg reappearance periods of anthelmintics against equine cyathostomins: The state of play revisited. Parasites & Vectors, 16, Article 96.
https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-023-05807-w