Livestock farmers must not “drop their guard” when it comes to liver fluke, experts from the Sustainable Control of Parasites in Sheep (SCOPS) and Control of Cattle Parasites Sustainably (COWS) have warned.
The organisations have said that, as forecast, cases of disease due to liver fluke have remained low so far, but that there are reports of both acute and chronic disease in some areas of the UK.
Philip Skuce of Moredun, who sits on both SCOPS and COWS, said that testing is critical to make sure farmers don’t treat too soon, or unnecessarily, or get caught out and miss a vital treatment.
“The cold snap in December will not have killed off all the liver fluke on pasture, so animals could still be picking up infection that could go on to cause disease,” he said.
“Livestock farmers must continue to test if they are to ensure any treatment is both necessary and given at the right time and with the most appropriate product.”
Diagnostic reports from the Animal and Plant Health Agency (APHA) and Scotland’s Rural College (SRUC) underline the value of using blood testing for fluke in sentinel lambs or calves, SCOPS and COWS said.
Heather Stevenson, a vet with SRUC, said that less than one percent of the animals tested in September and October 2022 were positive, which shows that the majority of farms did not need to treat at that stage.
“This rose to 10% by mid-November and 13% in December, which is still a small proportion of farms and highlights the potential to treat unnecessarily or too early if traditional timings are followed,” she said.
“In January, 30% of samples tested for coproantigen (a faecal test) were positive, which underlines the need to keep checking sheep that have not yet been treated.”
John Graham-Brown of the University of Liverpool said that repeat testing until the risk period is over is vital in controlling disease.
“A negative test does not mean you can sit back and relax. Plan to repeat tests in three to four weeks’ time to make sure you don’t get caught out,” he said.
SCOPS and COWS said that now is a good time for housed cattle to be tested for fluke using a composite dung test to check for fluke eggs.
If cattle are positive, they said, choosing a treatment that targets adult fluke and avoiding products containing triclabendazole will reduce resistance selection pressures on the parasite.
