The Department of Agriculture has released its liver fluke forecast for this winter, and it sees an increase in the prevalence of liver fluke infections when compared to 2022. It follows on from Animal Health Ireland’s update for liver fluke damage picked up in factories in quarter two of 2023. Under it’s beef health check programme, AHI records both herd and animal level liver fluke slaughter prevalence per county for homebred cattle under 30 months of age, compiled from Beef HealthCheck slaughter data.

Liver fluke damage for quarter two of 2023 was most prevalent in Donegal, Sligo and Mayo. Donegal registered 60.38% of all herds having liver damage due to liver fluke. There was active fluke in 34% of the herds.

Sligo registered the largest amount of herds in the country with liver damage, coming in at 81.48%. Active fluke was found in 38% of herds.

Mayo made up the top three counties for herds slaughtering cattle with liver damage. Here, 66% of herds that slaughtered cattle from Mayo had liver damage, while 12% of herds had active fluke in cattle at slaughter.

A report issued last week by the Department of Agriculture health surveillance unit highlights the increased incidence rate of infection with rumen fluke over the last number of weeks.

The report says: “In the past few weeks clinically significant larval rumen fluke infections have been reported in both sheep and cattle by both Athlone and Sligo RVLs. We suspect this may be related to the increased rainfall in the catchment areas of these RVLs. The cases typically occur late in the grazing season, usually with a history of sudden death or unresponsive diarrhoea in sheep and cattle.

“It has been usually seen in weanlings at the end of their first grazing season, but all ages are susceptible.”

What is rumen fluke

Rumen fluke is a parasite very similar to liver fluke and uses the same snail as its intermediate host. The adult parasites live in the rumen, while the immature larval forms live in the small intestine – it’s here where most of the damage is done. Clinical disease is due to intestinal damage caused by massive numbers of larvae in the small intestine (larval paramphistomosis). The adult flukes in the rumen are large and eye-catching at post mortem, but are not usually considered to cause of disease.

Clinical signs include dullness, dehydration, rapid weight loss and a severe watery scour, which may contain traces of blood.

Prevention and treatment

Restricting access to fields, or parts of fields, which are or have been wet or water-logged will reduce exposure to contaminated herbage. Most of the drugs that control liver fluke do not kill rumen fluke. Products containing oxyclozanide can kill both mature and immature stages of rumen fluke, but those are in short supply on the Irish market at the moment.

Speaking to the Irish Farmers Journal, Midlands-based vet Donal Lynch said: “ We have been seeing a higher incidence of both rumen fluke and lung worm in animals for the last four to six weeks. It’s been a very mild, wet autumn and these are ideal conditions for both fluke and lungworm. Rumen fluke generally doesn’t occur in older animals and tends to be an issue when immunity levels are low in animals, or other issues are present.”