Having a worm control plan is not just about having it written on a piece of paper, it is about having a three-way conversation between the farmer, vet and Registered Animal Medicines Advisor (RAMA).

“People tend to think having a worm plan is about writing a strategic plan on a bit of paper, but we all know farming isn’t like that,” said RAMA’s Lesley Nichols of Mole Valley Farmers, who added that the most useful plans are formed with communication between all three parties.

Developing a plan boils down to understanding what is happening on individual farms at key points in the year, as well as the farm structure and management, facilities available, and being aware of any resistance issues.

Mrs Nichols says getting out to farm at key points in the year is critical to establish what is happening on the ground to inform conversations around worm control planning. The most important times include:


Spring or when lambs are 4-6 weeks old

May-June to assess fly control and worms


Whilst on farm it is important to review a worm control plan to assess what has or has not been successful and update it at least annually.

FEC tests

Conducting faecal egg count (FEC) tests during these times will help to build up a picture of which parasites are posing an issue, to determine the need to worm and highlight certain pastures that may be more at risk at key times.

She added: “As a gold standard, we would recommend conducting faecal egg count tests in lambs every three to four weeks throughout the grazing season.

“It costs about £9.95 for a sheep test, which is money well spent considering it may save in wormer costs if they aren’t required. Importantly though, it will help us prescribe the most suitable wormer at that time and reduce the resistance pressure through unnecessary treatments.”

Faecal egg count testing is something Mrs Nichols hopes more farmers will adopt with about half of her customers currently using it.

“FEC tests have got to be part of a worm plan to give you an accurate understanding as to what is happening on that farm. They ensure a targeted approach to worm control, treating the right parasite, at the right time and with the right product. When farmers come into the store and ask to buy a specific wormer, I will ask them if they have conducted a FEC test. It’s important we get more farmers buying into the concept,” she said.

Farm system

In addition to knowing the worm risk, Mrs Nichols says a plan should also consider the type of farm production system, as this can determine the suitability of a worming product.

She said: “If stock is not going to be on the farm long, then a product that has short meat withdrawal period would be advised. Likewise, when stock are going to be grazing away from the farm and handling during that time may be difficult, then a product that offers a longer duration of protection may be required.”

Other factors to consider when putting together a worm control plan include handling equipment, husbandry and grassland management.

Drench testing

Drench testing is also something farmers need to be thinking about to identify any anthelmintic inefficacy. “You can’t start talking about a worm control programme if you don’t know the level of resistance. It is good to have this information early to avoid production losses from ineffective treatments throughout the season.

“Normally, the first point farmers will realise they have a resistance issue is when the product they are using isn’t working. This can be avoided if post drench FEC tests are conducted,” she said.

Mrs Nichols stresses the importance of using wormers responsibly. “I want a long-standing relationship with my customers. At the forefront of our minds has got to be looking after the resistance issue,” she said.

Responsible use of Moxidectin

Last year, the Sustainable Control of Parasites in Sheep (SCOPS) group and Zoetis issued a statement about the use of moxidectin in ewes at lambing time, with the priority to reduce over-treatment and to help preserve it as an anthelmintic for worms.

To do this, farmers should have a worm control plan in place and follow the SCOPS Principles, says Zoetis Vet Ally Anderson.

“In practice, this means sheep farmers working with whoever prescribes their anthelmintic, be it their vet or RAMA, to avoid over and/or unnecessary use of moxidectin, ensuring the treatment is always given at the right dose rate and administered correctly and allowing some worms to remain unexposed to the treatment.

“It is vital we look after these products to ensure their future use,” she said.

The SCOPS and Zoetis advice is:

Year on year use of moxidectin in ewes around lambing is unadvisable in any flock

If ewes are treated for worms with moxidectin at lambing time, at least 10% must be left untreated

Moxidectin 2% should not be used more than once in any flock in any one year

Where moxidectin 2% has been used in ewes to suppress the spring rise then it should not be used to treat sheep scab (or vice versa)

Check the dose rate and administration method

For further information and advice, please contact your animal health provider.