Dairy herds struggling with liver fluke should consider a pre-turnout, flukicide-only lactating cow treatment to clear out adult flukes.
“If fluke has been diagnosed, there’s a strong case for treating housed milking cows in February and March. At this time of year the animals have been housed for three to four months and there should only be adult fluke present in the cattle and treatment now with oxyclozonide will kill adult flukes in the bile ducts and prevent them laying eggs
that will contaminate pasture. Treatment before cattle go out to grass will also help take the pressure off the other available flukicide treatments later in the year,” says MSD Animal Health veterinary adviser Matt Haslam MRCVS.
Fluke problems are escalating, whilst at the same time the available flukicide control options are being restricted. Consequently, he says it is crucial that dairy farmers work with their vet to obtain a diagnosis of their liver fluke situation and threat on their own farm. And then discuss the latest best practice flukicide usage advice.
“From a diagnostic point of view, a bulk milk test is the first starting point. The result will tell you if your herd has been exposed to liver fluke. If the result is negative you still need to remain vigilant – particularly if your farm is wet – but if it is positive your vet will need to carry out further investigation. This may involve taking faecal samples for analysis or even blood sampling any thin or scouring animals.”
Matt Haslam says it vitally important that everyone works together to follow good codes of practice for the control of liver fluke. “We can no longer afford to blanket treat large groups of animals. And flukicide usage guidelines and milk withdrawal periods must be followed accurately. For example, oxyclozanide – available as Zanil in the UK – has a 72-hour milk withhold.
“It is also important to consider that some flukicide products, such as albendazole, have activity against gastro-intestinal worms. Whilst this may sound like a good idea, wormer products should only be used when worms are a problem. If you are using a product with activity against fluke and worms, you may be inadvertently selecting for resistance in the worm population, which could cause significant problems in the future,” he says.