Farmers urged to monitor sheep closely as worm egg counts spike

The latest results from the Zoetis Parasite Watch Scheme revealed worm egg counts in lambs varying from 70 to well over 700 eggs per gram (EPG) at the end of August, with an average of 380 EPG.

Therefore, farmers should consider conducting faecal egg counts (FEC) on their animals, which is also a good indication of the need for treatment in lambs alongside growth rates.

The Zoetis Parasite Watch Scheme collects data from 26 farms to provide a comprehensive parasite tracking service. Each farm takes FEC samples every 2-3 weeks through the spring and summer, with results uploaded to www.parasitewatch.co.uk.

Zoetis vet Patricia van Veen said the extreme and variable weather is making predictions difficult and is likely contributing to localised spikes in FECs. Parasite Watch data from previous years shows the parasite challenge remains a real risk into the autumn.

“Fluke is more challenging to monitor through FECs at this time of the year, as the time between infection and egg production, known as the pre-patent period, is 10-12 weeks. During this period, the early immature migrating larvae do a lot of damage, causing the disease known as acute fluke in any age of sheep,” she explained.

“Ewes and rams also need monitoring in the approach to tupping as fluke burdens could impact their condition and conception rates.”

Sheep farmer John Yeomans from Newtown, Powys, who takes part in the parasite watch scheme, said he treated his animals earlier this year due to the increased parasite risk and challenging summer.

He tups 530-550, mostly Beulah ewes and 170 ewe lambs each year, bringing them back to the home farm in October and returning them to the hill in December until lambing.

“Our farm is heavily stocked, with the ewes grazing high-up, so we demand a lot of them,” he said.

“Over the past decade, we have noticed that fluke can pose a real risk on our farm, sometimes resulting in dead sheep. We have done post mortems on them before and found them to be full of fluke.”

John, who farms with his wife Sarah and three sons, Tom, Jack and Joe, says he not only monitors worms and fluke by regular testing but is also trying to do more targeted worming based on weight gains in lambs.

“We must use medicines responsibly to safeguard their use,” he added.

Mrs van Veen stressed the importance of farmers working with their animal health provider to select the best product, particularly when there is a mixed parasite burden in their lambs.

“CYDECTIN TriclaMox Drench for Sheep is one option for treating lambs for mixed fluke and worm burdens. It contains the potent active moxidectin (3-ML group), which persists for 35 days and will treat stomach worms. The other active ingredient is triclabendazole, which is effective against early immature as well as late immature and adult fluke.

“However, if fluke is not an issue, then a persistent 3-ML wormer, such as CYDECTIN Oral Solution For Sheep can be used to selectively treat lambs during the Autumn as challenges have been shown to remain high during this time of the year,” Ms Van Veen explained.