Vet urges UK sheep farmers to test for liver fluke as risk extends later into the season
Ally Ward, a vet at animal health company Zoetis, says climate change and drought have pushed the liver fluke risk for sheep later into the year. Farmers are advised to keep stock away from damp areas and to test flocks.
Sheep farmers in the United Kingdom are being advised to avoid damp, muddy ground and to test flocks for liver fluke, as climate change and drought have shifted the risk of the disease later in the year. The warning comes from Ally Ward, a veterinary surgeon at the animal health company Zoetis. Liver fluke is a parasitic disease that threatens sheep and can cause health problems and financial losses on farms.
Why the risk has shifted
The parasite is carried by mud snails, which thrive in damp environments such as ditches, boggy ground, pond edges and slow-moving streams. According to Ward, this summer's drought caused the snails to "wait out" the dry weather. The wet and warm autumn that followed has created ideal conditions for them to contaminate pasture.
Historically, liver fluke has been more common in the wetter western and upland regions of the UK, including Wales, Scotland, western England and Northern Ireland. Slaughterhouse condemnations and laboratory surveillance now indicate that it is appearing in areas previously unaffected.
The disease normally affects sheep in wet, warm conditions above 10°C in mid-autumn, but it is now stretching into October and hitting flocks later in the year.
Recommended measures
Farmers are urged to keep livestock away from damp areas, where exposure to the parasite is greatest. Ward says preventative measures and treating sheep with a flukicide, a drug against liver fluke, are critical parts of a flock health plan, aimed at protecting flock health and welfare as well as farm finances.
Sheep farmer Peter Baber runs a 400-acre enterprise with 900 ewes across two holdings on the edge of Dartmoor National Park. He relies on Sustainable Control of Parasites in Sheep (SCOPS) alerts, and when one reports a liver fluke case, he takes faecal samples and sends them for a coproantigen test.
Ward notes that this test can detect the parasite four to seven weeks after infection, whereas traditional faecal egg counts only turn positive 10 to 12 weeks after infection.
