A map detailing the predicted risk of disease caused by liver fluke (Fasciola hepatica) infection in livestock for this winter has been made available to farmers.
This year’s liver fluke risk forecast is based on meteorological data gathered between May and October 2024 by Met Éireann.
The advice to farmers has been made available by the Department of Agriculture, Food and the Marine (DAFM) in collaboration with Met Éireann, UCD, Teagasc and Animal Health Ireland.
The research predicts infection being most prevalent in the west and northern half of the country, with a somewhat lower disease prevalence in the south-east of the country.
The Beef HealthCheck programme, run in partnership with Meat Industry Ireland (MII), collects and reports fluke information in cattle at slaughter from participating meat factories nationwide.
While fluke levels have generally remained low for the last few years, this year has seen the first increase since the programme began in 2016, as reported by Agriland earlier this week.
The map below includes the Ollerenshaw Summer Index values for 2024, and the risk of disease due to liver fluke:
To date this year, abattoir examinations have shown an average of 39% of herds having at least one animal with liver fluke damage.
Active infection in one or more animals was seen in 17% of herds, compared to only 13% last year.
Counties in the north-west of Ireland were more heavily affected, with 70-80% of herds in Sligo, Leitrim, Roscommon and Donegal reported to have signs of liver fluke at slaughter.
The prevalence within herds is typically low depending on the farm with 7% of animals presented to slaughter showing signs of liver fluke damage and 2% of animals showing live liver fluke parasites.
Liver fluke risk
In order to assess the risk of liver fluke disease on any particular farm, various environmental factors, particularly climate, landform and soil type must be taken into account.
The intermediate host of the parasite, which is a mud snail (Galba truncatula), occurs in soil that is slightly acidic and muddy.
Areas with rushes or wet patches are particularly important with regard to liver fluke risk, as they can help to maintain a population of the infective stage of the parasite.
In addition, livestock owners should factor in prior fluke history on the farm as this is an important indicator of future disease risks.
Infection tends to be chronic in cattle, resulting in ill-thrift and poor performance.
Chronic disease can also occur in sheep but infections may also result in more acute clinical signs, and sudden death in cases of heavy challenge.
Livestock owners should be vigilant for any signs of illness or ill-thrift in their animals and consult with their private veterinary practitioner (PVP) if they are concerned.