Liver Fluke Disease Alert - 19/02/2024
Now that we have entered 2024 liver fluke are still a major cause of death in both sheep and cattle. RVLs have reported that postmortem investigation into a variety of signs including sudden death, ill thrift, inappetence and weakness in both sheep and cattle have returned a diagnosis of acute/ sub-acute liver fluke disease (fasciolosis).
This is unfortunately confirming the predictions in this year’s liver fluke forecast, jointly issued by the Department, Met Éireann, Teagasc, Animal Health Ireland and the UCD Veterinary School. This is very late in the season to have such a number of these cases due to fluke and is due at least in part to the unseasonal warm and wet conditions seen in the late summer and continuing right up until the present time in Ireland. Deaths due to severe sub-acute fluke disease have been seen in weanling cattle as young as 8 months of age recently.
As stated by this year’s Liver Fluke Forecast ‘’The Ollerenshaw Summer Index 2023 predicts infection being prevalent across all areas of Ireland with the exception of south Leinster where the risk of disease is somewhat lower’’. While the weather is not the only factor controlling levels of liver fluke disease this year’s weather has provided ideal conditions for the fluke’s intermediate host, the mud snail, Galba truncatula (formerly Lymnaea truncatula), allowing it to thrive in the ground conditions that it prefers, in slightly acidic muddy soils such as rushy areas or waterlogged areas around troughs gateways etc.
All farmers who have a previous history of liver fluke on their farm should consult with their private veterinary practitioner to ensure they have an appropriate control plan in place, in light of the current favourable fluke conditions. It is vital that all farmers are aware of this risk so late in the year and that ill thrift, illness or unexplained deaths are investigated by their private veterinary practitioner who may wish to refer faecal samples for testing or carcasses for post mortem examination.
Image 1 : Liver with haemorrhagic migratory tracts in the liver and fibrin deposition on the hepatic surface
Image 2: on cross section multiple migratory fluke evident in the biliary system.