Treating early is not an insurance policy against liver fluke

Before deciding whether to treat your livestock for liver fluke this autumn, the Sustainable Control of Parasites in Sheep (SCOPS) and Control of Cattle Parasites Sustainably (COWS) groups are encouraging farmers to first test whether treatment is needed.

Liver fluke (fasciolosis) is the disease caused by Fasciola hepatica, a trematode or flat worm; it is estimated to cost UK agriculture around £300m every year.

Historically, control has relied heavily on the routine blanket use of flukicide treatments. While these medicines remain a vital component of liver fluke control, it is important to ensure that flukicides are only used when necessary, supported by testing.

Speaking about this, John Graham-Brown of NADIS and the University of Liverpool said: 

“In recent years, changeable weather patterns have emphasised how variable the liver fluke challenge is, both in terms of its extent and timing, and 2025/26 is following this trend.

“For several years now, the fluke challenge has been lower and later than traditionally expected in many parts of the country. However, many farmers are sticking with traditional treatment windows, meaning a large proportion of treatments are being given too early.

“This leaves livestock susceptible to disease, as the challenge typically increases through the autumn and into winter. There is no 'insurance’ element associated with a fluke treatment given too soon.”

Testing before treatment is key

Testing and monitoring to ensure you only treat your livestock when needed is the first step to safeguarding flukicides.

Tests – either blood or lateral flow – can detect early infection from as little as two weeks after flukes are ingested. By testing every 3–4 weeks you can determine when to treat your livestock and avoid unnecessary and costly treatments.

If treatment is necessary, it is important that you choose the right product and check it has worked effectively. In our guide, we outline the different flukicide active compounds available in the UK and the optimum time to use them.

Re-infection of treated livestock is often mistakenly linked to treatment failure. However, no flukicide products offer persistent protection as they only treat the current infection.

Product choice and timing are, therefore, key for sustainable control of liver fluke.

Speak to your vet or Registered Animal Medicines Adviser (RAMA) to discuss options.

Further information about liver fluke