ao link
Farmers Guardian
Over The Farm Gate

Over The Farm Gate

This Is Agriculture - Sponsored

This Is Agriculture - Sponsored



Auction Finder

Auction Finder

British Farming Awards

British Farming Awards

The Mart's the Heart

The Mart's the Heart



United message on use of newer wormer actives

SCOPS, with the backing and support of the Moredun Research Institute, the National Sheep Association and the Sheep Veterinary Society, has issued a letter to the sheep sector with renewed advice to farmers to include the newer group 4 and 5 wormers in their worm control plans now.

United message on use of newer wormer actives

The message is that for the maximum benefit, treatment with these wormers should happen on every farm every year, both to keep lambs growing to their potential and to maintain the older cheaper wormer groups as an effective option for as long as possible.

See below for the full letter.


Why is worm control so important?


Untreated worm burdens can negatively impact lambs, reducing their ability to thrive.

Signs include a depressed appetite, less feed intake and reduced growth rate.

Permanent gut damage reduces the rate of nutrient absorption and can cause scouring.

Therefore, managing worms through a strategic anthelmintic programme and following best practice is crucial to keep lambs healthy, happy, and growing.

It can also protect the flock from imported resistant worms through use in quarantine.


Understanding the risk


Anthelmintic resistance is one of the biggest challenges facing the health and profitability of the entire sheep industry, with 98 per cent of farms identifying some level of resistance to group 1, 2 or 3 wormers1.

Elanco’s ‘Wake Up to Worm Resistance’ campaign aims to raise awareness and tackle this major issue.

n Find out more about anthelmintic resistance, including useful tools including the Sheep Wormer Checker, at

Read More

Effective worm control key to sheep enterprise sustainabilityEffective worm control key to sheep enterprise sustainability
Sheep sector urged to incorporate new wormer groups nowSheep sector urged to incorporate new wormer groups now



1 - WAARD Study 2015

Farmer successfully incorporates new wormer technology

Using a group 4 ‘orange’ wormer as a quarantine dose for incoming sheep, and as part of a wider worming programme for lambs, is key to parasite management at Leicestershire-based Kilby Grange Farm, run by Bob Adams.


Kilby Grange runs a flock of 700 sheep over 55 hectares, with replacement breeding stock bought-in annually.

Mr Adams says: “Northumberland Black Face cross Bluefaced Leicester ewe lambs arrive on-farm in mid- to late-September, with new Charollais and Charmoise rams bought-in in October.

“Upon arrival, all stock is initially housed and subjected to quarantine protocols.

Alongside other treatments, such as clostridial vaccines, all new stock is dosed with Zolvix™ to stop the introduction of potentially resistant parasites.

“The new sheep stay indoors for 24-48 hours, to prevent pasture contamination, before being turned out.

The ewe lambs will remain in a separate group until they have lambed,” he says.




This process helps stop resistant parasites being shed onto grazing, helping to preserve the efficacy of older classes of wormers, while protecting his sheep from the negative performance effect of resistant worms.

Mr Adams has historically wormed lambs every three weeks, alternating group 1, 2 and 3 wormers annually, in a bid to avoid the build-up of resistance.

“We started finding our old worming protocols were not working as well as we’d have liked.

And although resistance was never formally confirmed, we knew it was the likely cause of our issues,” he says.

“So we attended several farmer meetings led by Nick Symonds of Mole Valley, where newer anthelmintic technology was discussed.

It was these sessions that encouraged us to switch to Zolvix for quarantine dosing, but also as part of a one-off annual treatment for our mid- to late-season lambs.

Mr Adams still uses the older classes of wormer when appropriate throughout the rest of the grazing season, but the addition of a single dose of Zolvix™ to clear out resistant worms has helped keep lambs growing and looking well.

This more strategic and responsible approach to anthelmintic use has also reduced overall wormer requirements on the farm, which should, in turn, decrease financial outlay as well as labour for dosing all while minimising the build-up of resistance.

Sheep industry experts stand together to urge action now

An open letter to all sheep farmers


As the grazing season progresses, we would like to remind prescribers of the need to encourage all sheep farms to integrate the two newer wormer groups (4-AD orange (Zolvix) and 5-SI purple (Startect)) into their worm control plans, as advised by the Sustainable Control of Parasites in Sheep (SCOPS) group.

Recent market research has shown that the vast majority of sheep farmers are aware of the threat of anthelminthic resistance (AR).

However, despite published studies showing the presence of AR on 98% of farms (WAARD study), 85% of farmers still believe that the wormers they use on their own farms are working as well as they always have.

This is because less than a quarter of those questioned use any method (e.g.

worm egg counts) to monitor treatment efficacy; and neither are the majority monitoring growth rates in their lambs, which would give them early warning of resistance developing.

Because most farmers can’t see the reduction in lamb performance, they are often reluctant to adopt new management practices (e.g.

routine worm egg counts) that would make this invisible problem visible.

Swapping a dose of an older grp 1 BZ, grp 2 LV or grp 3 ML wormer to a grp 4 AD or grp 5 SI in the latter part of the grazing season will give a visible improvement in performance in most cases as worms left by previous treatments are removed.

The two newer groups used in the latter part of the season can help lambs to reach their growth potential by removing the build-up of worms that have survived previous treatments.

In addition, this treatment helps slow the development of resistance to the older three groups of wormers, if they are deployed before the older wormer groups become ineffective.

This is why action now is so important.

The aim is for one of the two newer groups to be used on all sheep farms at two points in their worm control plan.

Firstly, as part of their quarantine treatments for all incoming sheep, and secondly as a one-off treatment for lambs, in the latter part of the grazing season.

An effective farm protection (quarantine) treatment is essential to prevent otherwise healthy sheep bringing resistant worms onto the farm.

For full details go to

To gain the maximum benefit from the treatment for lambs, it is important that the treatment is given in the latter part of the grazing season (as a mid-late season break dose), when a treatment is deemed necessary (following a significant worm egg count), and all lambs remaining on the farm should be treated.

NOTE: To avoid the risk of selecting for resistance to the newer group 4-AD & 5-SI wormers, it is very important not to “dose and move” lambs to “cleaner” grazing straight away.

To avoid this risk simply drench the lambs and return them to the same fields for four or five days before moving them.

For more details on mid-late season break dose go to

This is a first step that all sheep farms can easily take to make the otherwise invisible problem of AR more visible, and help them take the next step towards more sustainable worm control and more efficient, profitable sheep farming.


For further information call Elanco Animal Health on +44 (0)1256 353 131 or write to Elanco UK AH Limited, Bartley Way, Bartley Wood Business Park, Hook RG27 9XA.

ZOLVIX™ 25mg/ml oral solution for sheep. Legal category: POM-VPS in UK.

Information regarding the side effects, precautions, warnings and contra-indications can be found in product packaging and leaflets; further information can also be found in the Summary of Product Characteristics.

Advice should be sought from the medicine prescriber. Zolvix, Elanco and the diagonal bar logo are trademarks of Elanco or its affiliates. Use medicines responsibly (

© 2021 Elanco or its affiliates.

Wake up to Worm Resistance

Wake up to Worm Resistance


Anthelmintic resistance is one of the biggest challenges facing the health and profitability of the entire sheep industry, with 98% of farms identifying some level of resistance to group 1, 2 or 3 wormers.


Elanco’s ‘Wake Up to Worm Resistance’ campaign has been launched to raise awareness and tackle this major issue.


Click here to visit the series homepage