A dry , cool spring across most of the UK , followed by some hot , dry spells over the summer , means the liver fluke risk is generally going to be low this autumn and winter . However , the Sustainable Control of Parasites in Sheep ( SCOPS ) and Control of Cattle Parasites Sustainably ( COWS ) groups say producers need to test on their own farms to avoid treating unnecessarily or being caught out – and need to consider treatment options carefully given the withdrawal of Trodax from the market .

Speaking on behalf of both groups , Philip Skuce of the Moredun Research Institute says : “ We are already beginning to see the first signs of liver fluke infection acquired this year . Using lambs and calves born this spring as sentinels for fluke infection in the West of Scotland , we have seen a significant proportion of both serum antibody and coproantigen tests come back positive . This suggests some animals encountered a fluke challenge as early as mid-July . This may seem odd in such a dry year , but many farms rely on field springs and streams to provide water

for grazing stock , which can lead to permanent wet patches where the mud snails can persist . This is supported by negative test results for a group supplied by a water trough .”

Matt Colston , a vet with Elanco Animal Health , adds : “ In a year like this , it is imperative we use the tests available to monitor the fluke situation on individual farms . We can ’ t just make assumptions based on general forecasts or previous history . Each farm needs to know if treatment is required , when to do it and what product to use .”

Details of the tests available to farmers can be found on the SCOPS and COWS websites .

The NADIS Liver Fluke Forecast , based on the latest Met Office rainfall and

temperature data , also suggests a generally low risk this autumn . However , there are indications of a moderate risk in some parts of the west of the UK , including Western Scotland and Northern Ireland , and the possibility of a higher risk where animals are forced to graze areas where snails are present . Avoiding areas such as open watering points is one way to reduce the risk to stock , with SCOPS and COWS recommending farmers access useful information from Moredun to Fight the Fluke and Test Don ’ t Guess .

Treatment options

The liver fluke treatment situation has been further complicated by the discontinuation of the flukicide Trodax . The injectable anthelmintic ( nitroxynil ), manufactured by Boehringer-Ingelheim , was licensed for use in sheep and cattle in the UK with activity against liver fluke from immature through to adult stages . It was valuable because of its spectrum of activity and because it was also a different chemical class to the other flukicides ( triclabendazole , closantel

etc ) so allowed for a strategic rotation of products .

The withdrawal of Trodax from the market means there are now only four actives authorised in the UK and available for sheep – and two of those are adulticides that only kill adult fluke . There are five actives in cattle , three of which are adulticides .

Rebecca Mearns , Sheep Veterinary Society President , says : “ To minimise the extra pressure on the only two actives that can kill immature fluke ( triclabendazole and closantel ), we need to be more careful than ever to make informed decisions about timing of treatment and product choice . We cannot afford to guess . There are good diagnostic tests available and we urge livestock farmers to consult their vet or adviser to decide how best to investigate whether fluke is present and what actions , if any , to take .”

www . scops . org . uk