Sheep producers are being urged to test this season’s lambs for liver fluke before treating their entire flock for the disease.
Advisory group Sustainable Control of Parasites in Sheep (Scops) says 2020 is an atypical year and the timing of peak liver fluke risk could be different from normal and vary across the country.
It is advising farmers and crofters to avoid the temptation to treat animals for fluke early in the autumn, as treatment at the wrong time may be a waste of time and money and offer no protection if animals become infected later in the year.
Producers are advised to use this season’s lambs as sentinels – an indicator of disease presence in a flock –and blood test them for the disease before considering treatment of the main flock.
“Farmers are increasingly using blood tests on lambs to check for infection in their sheep because this is the best diagnostic test at this time of year,” said Professor Diana Williams from Liverpool University.
“The test can detect infection much earlier than faecal methods, which rely on the liver flukes being more mature. Lambs are ideal as an early warning because they can only have picked up liver fluke this season.”
Pete Webster, who farms at Matson Ground Estate, Windermere, blood tests lambs that have been kept with ewes to identify the best time to first treat the ewe flock for fluke.
He said: “We have suffered with fluke in the past and this is the best way to ensure we are spot-on with any treatments. If the first lamb tests are negative, we will retest in a month to check again.”
Scops advises sheep farmers interested in blood-testing lambs to test between six and 10 sentinel lambs every month.
Once lambs start testing positive for fluke they are advised to speak to their vet to arrange further testing. Once the lambs are confirmed as being infected with liver fluke, they should then treat the rest of the sheep on that ground.