December liver fluke update

We last sent out our liver fluke forecast and thoughts in November, so thought that now would be a good time to update things given that we are approaching or already in a handling window for ewes in mid pregnancy.

We still haven’t seen any evidence of recently acquired liver fluke infection in sheep coming through the postmortem rooms at Dumfries and Glasgow. The results of this autumn’s serum Fasciola hepatica antibody ELISA testing are shown in the table below with a relatively low number of positives. The antibody ELISA can detect infection from around four weeks into the lifecycle.

Coproantigen results for the same period are summarised below. Coproantigen can pick up fluke infection from around eight weeks into the life cycle. This test is often used to investigate ill thrift in addition to being used as a monitoring tool. Positive results in adult sheep may represent chronic fluke infection. Again, a relatively low number of positives.

Cases of acute fluke have recently been reported from Northern Ireland and the North of England, with Ireland also reporting enteritis due to acute rumen fluke.

Migration of immature fluke and probable secondary Clostridium novyi (black disease) infection was detected on histopathology of a section of lamb’s liver submitted from a holding in Fife during November reaffirming the importance of clostridial vaccination in preventing sheep losses.

It would be sensible to remain alert for outbreaks of acute/sub-acute fasciolosis into the first month or two of 2024.

Again, it is worth stressing that while general information is useful, local decision making based on farm and field specific factors is essential.

All types of liver fluke testing are now eligible for the Scottish Government’s Preparing for Sustainable Farming funding under the liver fluke investigation option for both cattle and sheep.

If you are diagnosing acute fasciolosis on farm please let us know.

Posted by SRUC Veterinary Services on 21/12/2023