Warning of high risk of liver fluke in areas of the UK

10^th October 2017

This press release was circulated on behalf of SCOPS by NSA. Sustainable Control of Parasites in Sheep (SCOPS) is an industry led group that represents the interests of the sheep industry.​

 

The monthly updates are based on the NADIS parasite forecast and other information from industry.

While rainfall over the winter of 2016-17 was relatively low, the rainfall pattern in June/July 2017 (see Met Office map) was higher than normal in parts of Scotland, Wales, North and South West England. Rainfall was lower in August (see Met Office map) but because of the wet weather earlier in the summer, there is a greater risk of fluke in these areas. NADIS is indicating the following this autumn,

• Western Scotland and South Wales – potential for a "high-risk" of fluke infection.
• Eastern Scotland, North West England, South West England, and North Wales – potential for a "medium-risk" of fluke infection.
• Central and eastern regions of England – currently forecast to be at "low-risk".
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The situation may change depending on rainfall during September and October.

To date, the group is aware of cases of acute fluke in sheep being confirmed in Cheshire during September. Positive coproantigen results have  also been reported - from lambs in South West Scotland and from Parasite Watch farms in South West England and South West Wales. These reports support the preliminary regional fluke forecasts.

Farmer advice

Livestock farmers are urged to:

• Check the fluke forecast for their area.
• Investigate any sudden deaths in sheep.
• Discuss testing (see below) and treatment options with their vet or animal health adviser.
• Where possible use management to reduce fluke risk, for example, remove sheep/cattle from the wettest fields or house early.
• Ask their abattoir for feedback on liver condition.
• Discuss quarantine protocols for new or returning animals with their vet.

Fluke testing options

Type of test	Test Result
Earliest warning Fluke Antibody test Blood sample to test for fluke antibodies. This will show the first signs of exposure to fluke. NOTE: This test is most suitable for lambs/calves in their first grazing season. It takes 2 to4 weeks for detectable antibodies to be produced. Following a wet summer this test may be more appropriate for use in areas/farms with a low fluke risk.	Positive Indicates that the lambs/calves have met a liver fluke challenge already this year. However it does not tell us the level of parasite challenge, or whether it is likely to cause any clinical disease, or decreased growth rates in the near future. Negative No exposure to liver fluke yet. This would suggest that for this group at least, either it is too soon after challenge for antibodies to be detectable or there has been no liver fluke challenge, and that treatment is not yet necessary. Other groups on the farm could still be at risk, depending on the areas they have been grazing.  On farms with a history of fluke, a repeat test 2-4 weeks later would be advisable. NOTE: Bulk tank milk can also be tested for antibodies to liver fluke.
Coproantigen ELISA Carried out on dung and is specific for liver fluke. This test detects the presence of active liver fluke infection when the volume of ‘excretions’ released from the fluke passes a certain threshold. It can detect fluke 2-3 weeks before eggs can be found in dung.	Positive Indicates an active liver fluke infection. Negative No fluke, or very low numbers, or young fluke which are so small that their secretions do not exceed the threshold. There could still be large numbers of immature fluke present.
Faecal Egg Count Fluke egg detection	Positive Egg laying adult fluke are present. Negative No egg laying adult fluke present. However, there could still be large numbers of immature fluke present.