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Early cases of fluke infestations on farms involved in the Zoetis Parasite Watch scheme have prompted farmers to take action early and treat stock.

Sheep farmer Steve Thompson of Trewern Farm, Llanilltern, Cardiff, has been monitoring worm and fluke burdens as part of the scheme since spring. Fluke results using copro-antigen testing, which picks up immature fluke from around six weeks of age, found fluke in ewes, rams and lambs on his farm in mid-August.

Mr Thompson has battled with this challenge on his farm for years and often loses one or two sheep annually to acute fluke.

He said: “I didn’t think fluke was a problem this early, with stock usually treated nearer to tupping time. Testing has opened my eyes to the problem. We now see fluke as an earlier problem and the tests have highlighted the issue before we lost any animals.”

Early fluke cases have also been reported by the Welsh Veterinary Science Centre (WVSC), which has seen three cases of Black Disease in cattle in the last two months. This is caused by the bacterium Clostridium novyi. Following damage to the liver by migrating fluke the bacterium produces toxins that cause death.

Zoetis vet Dr Dave Armstrong says farmers frequently get caught out by fluke due to delaying treatment until nearer to tupping or housing time and reminds that both immature and adult fluke cause production loss.

All farms that contain wet areas could be at risk of fluke, as it’s those conditions that favour the fluke’s intermediate host, the mud snail.

Dr Armstrong said: “Anywhere that is wet, such as around gateways and water troughs, can provide the ideal location for the mud snail. If you detect fluke early and treat stock, then you can reduce the risk going forward by stopping the lifecycle before it infects pastures.”

Sheep require constant management of fluke because there is often no break in the grazing cycle. So, with no product persistent against fluke, a sheep treated one day can pick up infection the next if they are grazing infected pasture.

Dr Armstrong said: “Although faecal egg tests will pick up fluke that are 12 weeks old, it won’t pick up immature fluke, which can cause acute disease and sudden death. Copro-antigen testing will pick up fluke from about six weeks old; a negative test doesn’t discount the presence of fluke under six weeks of age.”

Dr Armstrong recommends using testing along with other resources, such as abattoir feedback, post mortems on sheep that have died for no known cause, and general stock health to make a decision on treatment.

For cattle, like sheep, no fluke treatment has persistency meaning they can become infected with fluke immediately after treatment, if they are grazing contaminated pasture.

Treating at housing cleans out parasites including fluke thereby supporting a healthier transition period. The benefits of this will extend into the new grazing season when the parasite burden on the pasture will be lower as a result.

Farmers can monitor fluke and worm levels in their area by clicking on an interactive map at parasitewatch.co.uk.