Sheep farmers are being urged not to panic when faced with new Haemonchus outbreaks amid reports the gut worm is becoming more prevalent across the UK.

Farm vets, Dawn Bowness from Clevedale Veterinary Practice in North Yorkshire, and Kaz Strycharczyk from Black Sheep Farm Health in Northumberland, sounded the warning in a recent discussion about Haemonchus control on an episode of The Webinar Vet’s podcast, “Vet Chat” in partnership with Elanco.

The episode follows an alert from Sustainable Control of Parasites in Sheep (SCOPS) which reported Haemonchus contortus, commonly known as Barber’s Pole worm, is becoming more prevalent and spreading further north in the country.

Ms Bowness said Haemonchus is no longer a problem restricted to the south of England, and in the right conditions, which tend to be a change from hot and dry weather to warm and wet weather, outbreaks are occurring across the country.

She added: “We can see clinical disease from spring right through to mid- to late-autumn, and as weather patterns change, this could change further yet.”

Mr Strycharczyk said clinical signs of Haemonchus differ from other gut worms because it does not cause scouring.

He added: “It’s a blood-sucking worm and in some ways, there’s overlap in symptoms with liver fluke.

“Really acute disease can cause sudden death, while the signs of sub-acute and chronic disease include bottle jaw, pale eye membranes and ill thrift.”

Both Mr Strycharczyk and Ms Bowness recommended farmers extend their faecal egg count (FEC) monitoring programmes to include adult ewes as high egg counts are often an indication of Haemonchus problems, however this needs to be confirmed with species testing in a lab.

Ms Bowness said: “Often Haemonchus catches farmers out as there’s a field of sheep that aren’t scouring, but when they’re put under some pressure, such as being gathered or moved, the anaemia they’re quietly suffering from becomes too much for them and there’s often mortality at this point.

“Never waste a dead sheep – post-mortems are a key cornerstone of diagnosing Haemonchus alongside FEC testing adult sheep.”

In flocks where Haemonchus has been confirmed, farmers are advised to speak to their vets about the most appropriate treatment and to follow the same treatment principles as they would for other parasite problems.

Mr Strycharczyk said: “In an acute outbreak where there’s multiple dead sheep, I’d generally recommend going in and treating everything in that mob, and doing a post-drench check seven to 14 days later to make sure whatever treatment you’ve used has worked.

“In less severe scenarios, you can use the FAMACHA scoring method to check their eyelid colour and assess for anaemia caused by Haemonchus – and be selective about which animals you treat.”

Ms Bowness said there is very little resistance to Haemonchus worms in the UK so all classes of wormers could be effective against the parasite.

She added: “People panic about Haemonchus because it’s new, but we should keep our heads and treat it like any other gut worm in terms of how we manage it to prevent anthelmintic resistance.

“We don’t want to end up in the same situation as a lot of the southern hemisphere where they’re unable to manage it because they did mass suppressive treatments to try and eradicate it.”