01/04/2026

The Problem with Single-Active Drenches

For nearly 50 years, Australian producers have relied on triclabendazole to control liver fluke.¹ However, widespread resistance means single-active formulations can no longer be relied upon for effective control. Recent studies have consistently confirmed the rise and spread of triclabendazole resistance^2,3, with a recent MLA backed study showing that every single property tested showed some degree of resistance to triclabendazole.⁴

Why Combinations Are the New Standard

To effectively break the liver fluke lifecycle, you must use a combination of actives. Products like Nitrofluke and Nitromec are the only two drenches in Australia that combine non-triclabendazole actives to ensure the most effective control of all liver fluke stages, including those resistant to triclabendazole.⁵

Strategic Recommendations

• Rotate Actives: Incorporate a nitroxynil-containing product into your program to manage resistance.
• Target All Stages: Use products that control liver fluke down to the 2-week-old stage to ensure better productivity and weight gain, up to an extra 13 kgs compared to treating adult liver fluke only.⁶ 
• Monitor Efficacy: Seek professional advice to monitor how well your liver fluke chemicals are working at least once every three years.

Looking for more information about liver fluke or other animal health advice? Find your local Virbac representative or contact your Nutrien branch.

References: 

1. NSW Department of Primary Industries. (2017, March). Liver fluke disease in sheep and cattle (Primefact 446, 4th ed.). https://www.dpi.nsw.gov.au/animals-and-livestock/sheep/health/internal-parasites/liverfluke-disease-sheep-cattle
2. Brockwell, Y. M., Elliott, T. P., Anderson, G. R., Stanton, R., Spithill, T. W., & Sangster, N. C. (2014). Confirmation of Fasciola hepatica resistant to triclabendazole in naturally infected Australian beef and dairy cattle. International Journal for Parasitology: Drugs and Drug Resistance, 4(1), 48–54. https://doi.org/10.1016/j.ijpddr.2013.11.005
3. Kelley, J. M., Mason, C. L., Barker, J. S. P., Haslam, S. J., & Hodgkinson, J. E. (2020). Prevalence of triclabendazole resistance in Fasciola hepatica from dairy cattle in Great Britain. Veterinary Parasitology, 277, 109015. https://doi.org/10.1016/j.vetpar.2019.109015
4. Meat & Livestock Australia. (2025, August 12). Flukicide timing tackles drench resistance. https://www.mla.com.au/news-and-events/industry-news/flukicide-timing-tackles-drench-resistance/
5. Refer to registered labels APVMA No. 70184 and APVMA No. 59844.
6. JC Boray (1982). Chemotherapy of fasciolosis. New South Wales Veterinary Proceedings, p42-47.

 *The benefits outlined in the scientific studies mentioned are not registered label claims. They are a guide to the importance of liver fluke control for livestock production. Outcomes may vary depending on farm management, fluke burdens and animal responses. Weight Gain is not a registered claim for Nitrofluke and Nitromec.

*DISCLAIMER: 

The information provided in this article is intended as a guide only. Information contained in this article has been provided by the manufacturer/ You should not rely on the information in this article, and it should not be considered advice. You should seek professional advice regarding relevant factors specific to your situation. This article does not take into account variable conditions that may impact performance. Always read and follow label directions before using any product in this article. To the maximum extent permitted by law, Nutrien Ag Solutions Limited and its related associated entities will not be liable for any loss or damage suffered by any person arising out of any reliance on any information contained in this article.