Animal health experts are urging farmers in areas that have a high risk of liver fluke to consider treating cattle two weeks after housing.
The National Animal Disease Information Service (NADIS) has forecast a high risk in Scotland, northern England and North Wales.
Cases are now being seen south of these regions, according to parasite experts with the Control of Worms Sustainably (COWS).
It is now are urging farmers in these areas to consider treating cattle two weeks after housing.
Professor Diana Williams of the University of Liverpool, said: “Treating infected cattle shortly after housing with a product containing triclabendazole, will kill immature and mature fluke provided no resistance is present.
“This will also ensure animals do not re-infect the pastures with liver fluke eggs next spring.”
Before reaching for the flukicide, she said it would be good for farmers to check whether treatments are justified.
“For example, is there a history of fluke on the farm, have animals been grazing muddy areas where intermediate host mud snails live, or have cattle been purchased from fluky areas?
“If the answer to these is ‘no’, treatment is unlikely to be necessary, saving time and money and helping to protect the few medicines available to combat this parasite,” she said.
Testing individual animals using new blood and dung tests can confirm if cattle have picked up liver fluke during the grazing season.
There are three active ingredients that will kill immature liver fluke – triclabendazole, closantel and nitroxynil, which can all be applied in the autumn and winter.
Professor Williams said that when using triclabendazole, it is a good idea to test to see if a treatment has worked by using a Faecal Egg Count Reduction Test (FECRT) afterwards, as there is evidence of parasite resistance to this drug.
Only two products are licensed for use in milking cows; albendazole and oxyclozanide – with withdrawal periods of 60-72 hours and 108 hours respectively.
The COWS group advises farmers to discuss product choice with their vet or SQP as part of their Herd Health Plan.
Professor Williams added: “Essentially, strategic treatment of ‘at risk’ animals in winter will help protect pastures in the spring.
“Unfortunately, there is no blueprint for liver fluke control – it very much depends on the farm, the animals and the weather in any one year.
“When treating cattle, producers should follow the COWS group’s 5 ‘Rs’ – the right product, given to the right animal, at the right time, at the right dose rate and in the right way.”
