An increase in cattle presenting for slaughter with liver fluke has been reported by Animal Health Ireland (AHI).

AHI’s beef health check programme manager Dr Natascha Meunier said heavy rainfall at the end of 2023 and the start of 2024 may be behind this rise.

“The previous autumn and winter season has brought wetter weather than usual. This may have had a boosting effect on internal worms.

“For example, the liver fluke life cycle includes a mud snail that thrives in damp environments and we are now starting to see an increase in animals with liver fluke at slaughter in the beef health check programme,” Meunier added.

Normally not problematic now

In the latest beef health check newsletter, the programme manager said while liver fluke is not usually problematic for cattle at this time of year if they were treated at housing, any adult fluke present in animals can lay eggs that contaminate pastures.

“These are liver fluke that may have been picked up in the last grazing season and were either not killed by winter flukicide treatments or were not treated.

“These also might be animals that have picked up liver fluke in the early spring,” she said.

Meunier added that with the increased summer rainfall last year, cattle may have picked up liver fluke earlier than usual or in areas which haven’t seen problems for a year or two.

“It may be necessary to test and treat the group or other animals on the farm if the reports are coming back positive for live liver fluke,” she added.

Increased reports

There have been numerous flags in recent months to increased liver fluke due to the heavy rainfall experienced.

A warning was put out by the Department of Agriculture’s animal health surveillance unit due to a spike in animal mortality linked to acute or sub-acute liver fluke disease in December 2023.

The report said at the time that it was very late in the season to have a high number of such cases due to liver fluke, citing that the disease is due at least in part to the unseasonal warm and wet conditions seen in late summer of 2023 and into the winter.

Furthermore, in February 2024 the Teagasc National Hill Sheep Conference heard that a growing multitude of factors, including climate and weather, has the potential to greatly increase the risk of liver fluke disease on much of the land area typically farmed with sheep.