Regular monitoring of livestock throughout the spring and summer can help inform farmers about parasite burdens on their farm and support treatment choices.

By monitoring worm egg counts, some farmers have even found their sheep required lower levels of worm treatments which in turn ensured cost savings.

That is just exactly what the farmers involved in the Parasite Watch scheme run by Zoetis, have discovered. The scheme, which is now in its third year, involves a network of farms across the country, taking faecal egg samples every two weeks to monitor worm burdens. Fluke is tested regularly during risk periods using copro-antigen testing.

Worm burden information is available within a few hours of testing on each of the farms which is then uploaded regularly to, giving a real-time picture as to what is happening on the ground.

Gareth Jones, Cilerwisg, Lampeter, Ceredigion, says he was shocked to see no worms in the group of lambs tested at the end of August last year.

“Normally we would blanket treat lambs at weaning, but we didn’t have to. It shows we were using too much wormer before and as a result have saved money. There’s no point taking a paracetamol if you haven’t got a headache,” he adds.

Mr Jones says he will definitely continue basing worming decisions on faecal egg count tests this year.

Likewise, Tom Carlisle, Coxons Farm, Skipton, says he would normally worm lambs, but as a result of taking faecal egg counts he didn’t because worm eggs counts were low.

“As a result of taking faecal egg counts we’ve not been dosing unnecessarily and have been dosing correctly.”

For Steve Thompson, Llanilltern, not only did monitoring faecal egg counts last year help him save money on treatments, but it also identified fluke earlier than expected.

He too would traditionally treat according to a schedule. He says: “I didn’t think fluke was a problem so early, with stock usually treated nearer to tupping time. Testing opened my eyes to the problem. We now see fluke as an earlier problem and the tests last year highlighted the issue before we lost any animals.”

According to Zoetis vet, Dr Dave Armstrong, no two years are the same when it comes to parasite activity, so farmers need to be aware of what is happening on their farm and take appropriate action based on the risk.

“Every year we see peaks at different times. For example, in 2017, we saw Nematodirus strike some farms later in the summer because we had a period of dry weather followed by sudden rain and an increase in temperatures. Farms were also challenged by fluke earlier in the season because of the weather.

“This is why it’s important farmers know what is happening in their area, use growth rates and faecal egg tests to build a picture on their own farm and monitor stock to check they are maintaining condition,” he adds.

Regularly monitoring stock and taking post treatment faecal worm egg counts can also highlight resistance issues.

Tests last year on John Hoskin’s farm in Dorset, revealed some resistance problems, which has reinforced the importance of taking egg counts.

He says: “Taking faecal egg counts allows us to keep on top of things. We are trying to use wormers sensibly and take preventative action.”

His vet Emily Gascoigne, stresses the importance of farmers knowing whether wormers are working on their farm. “As a minimum, farmers drenching sheep should be following up with a post drench check test to see whether the product has worked. If you go to the petrol station and put diesel in your tank you always check it is full afterwards, in the same way you need to check the worms have been removed," she said.

Monitor fluke and worm levels in your area

Farmers can monitor fluke and worm levels in their area by clicking on an interactive map found at

Parasite Data from farms involved in the Zoetis Parasite Watch scheme will be updated regularly, which will allow farmers to see if there are spikes in certain parasites throughout the year in their area and enable them to take appropriate action.

To use the map, click on a farm in your area and details of any parasites that have been found as well as when they were detected will be displayed.