Liver fluke infection is predicted to be prevalent in the west and northwest this winter.

This is what the the Department of Agriculture, Food and the Marine (DAFM), in collaboration with Met Éireann, University College Dublin (UCD), Teagasc and Animal Health Ireland, has predicted in its liver fluke forecast.


The Ollerenshaw Summer Index 2022 predicts infection being prevalent in the west and northwest, with occasional losses in the midlands, east Munster and north Leinster.

Little or no losses are expected along southern coastal fringes and in south Leinster. 

Source: DAFM

The lower values of the index are due to the drier conditions in June, July and August, especially in the south and east.

May was dry in the south, whereas it was wet in the northwest, reflecting in the higher values. June was wetter in the west than the rest of the country, resulting in the overall index values being higher in the west and northwest. 

Liver fluke infection in cattle

This year’s levels of liver fluke infection are very similar to those reported in 2021, according to the data collected.

To date, abattoir examinations have showed an average of 44% of herds with at least one animal with liver damage due to liver fluke, and live liver fluke parasites were seen in 13% of herds.

The data, collected by Beef HealthCheck programme, run in partnership with Meat Industry Ireland, found that counties in the northwest of Ireland were more heavily affected.

70-80% of herds in counties Sligo, Roscommon and Donegal were reported to have signs of liver fluke at slaughter.

Live fluke infection in sheep

Since 2015, from June to December, the DAFM has collected blood samples from lambs in meat factories from a proportion of flocks at the time of slaughter.

These have been tested for the presence of liver fluke antibodies to determine the timing and geographical spread of liver fluke exposure in grazing lambs.

Blood samples from 354 flocks from July to August 2022 across 26 counties were tested for the presence of liver fluke antibodies.

Data from this survey showed that the majority of infected flocks are from counties on the western seaboard.

Some positive and inconclusive results were found in counties outside of the west and the northwest in the August testing, possibly associated with a high summer rainfall level.

By October, as well as a lot of positive and inconclusive results in counties on the western seaboard, there was substantial evidence of fluke exposure in lambs from the border areas, midlands, in the south and in Leinster.

MonthNo. Flocks TestedNo. ELISA PositivePositive (%)
2022 Survey of the prevalence of liver fluke infection in Irish sheep flocks