Forecasts based on climate data indicate there is a high risk of liver fluke on NI livestock farms this autumn and winter.

The forecasts by the Agri Food and Biosciences Institute (AFBI) are based on an average total rainfall of 94mm from May to September 2025, which is 16% higher than the long-term average.

Similarly, the average monthly temperature from May to September 2025 of 14 degrees Celsius was 9% above the long-term average.

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High temperatures and rainfall are ideal for the fluke’s intermediate host, the mud snail, to breed and for the fluke larvae to develop

AFBI state that the climate-based model used to predict liver fluke infestations, known as the Ollerenshaw Index, is currently above 400.

“This level prompts a forecast of high prevalence of fluke infection in stock if appropriate measures are not taken,” AFBI said.

When treating livestock at this time of year, a product that is effective against both immature and mature forms of fluke is needed.