Peatland restoration is unlikely to increase the risk of liver fluke infestation in livestock using it, but as with any grazing land, testing is key. That’s the conclusion of new research by the Moredun Institute highlighted in a just-published NatureScot Peatland ACTION case study.
Liver fluke is a highly pathogenic flatworm parasite of sheep and cattle. It’s spread through an intermediate host – a tiny snail called Galba truncatula, that thrives in wet, muddy conditions. This has led to farmers and crofters asking if peatland restoration, which involves rewetting and revegetating areas of damaged peatland to reduce carbon emissions, could lead to a greater risk of infection for stock grazing the land.
However, Peatland ACTION’s case study, Peatlands and Liver Fluke, highlights research in Shetland by the Moredun Research Institute, which has found that the acidic nature of peatlands, coupled with the lack of mud, mean that this is unlikely to be the case.
Two scientists, Dr Philip Skuce and Gillian Mitchell, from the Moredun Research Institute, studied the impact of peatland restoration on the prevalence of liver fluke in sheep at seven peatland sites across Shetland. Only three of these sites were positive for liver fluke, as determined by faecal egg count analysis of sheep grazing these sites..
At Sandy Loch, one of the three positive sites for liver fluke, the researchers didn’t find any mud snails (or mud) on the restored peatland itself, but did find hundreds of the Galba snails on the gravel track to and from the site, where the sheep would communally graze. Subsequent analysis revealed around 10% of these to be infected with liver fluke.
Their working hypothesis now is that the sheep may have acquired liver fluke infection from grazing around the marginal areas leading to and from the restored peatland site, but not on the peatland itself. And while they were not able to confirm it, the sheep may also have been harbouring liver fluke infections from grazing on in-bye land at their respective home farms.
Commenting on the findings of the research, Dr Philip Skuce said: ‘
‘What our research so far has demonstrated is that it is possible to engage in ‘conservation grazing’, and agri-environment schemes, including peatland restoration, with all the potential environmental benefits these bring, without compromising animal health and welfare. But the key to this is testing or monitoring animals grazing these sites. We can speculate about high/low fluke risk, but sentinel animals grazing these sites are the best indicators of genuine fluke risk.’
Gillian Mitchell added:
‘It’s important for farmers and crofters to know what tests are available for liver fluke and to understand what each tells you about fluke infection status. This will determine your grazing management and whether you need to treat animals for fluke or not!’
Sue White, a Peatland ACTION Project Officer with the Shetland Amenity Trust, added:
‘The conclusions from this work will be hugely reassuring to local land managers who are interested in peatland restoration but have concerns about animal welfare.’
Sally Blyth, Peatland ACTION Data and Evidence Manager explained why Peatland ACTION were so keen to highlight the work:
‘We have enjoyed working with the Moredun Institute to investigate the scientific evidence for any link between peatland restoration and liver fluke infection. We want to explore and help resolve land manager concerns like these to help them make informed decisions around stock management and peatland restoration activity.’
In the case study Dr Skuce also explains that on any grazing land, whether it be peatland, grassland, saltmarsh or in-bye land, it is important to be able to risk-assess a field or farm for fluke, recognise the mud snails and their habitat, understand when to test, and use the results of that testing to decide the best times to administer medication, if required. There is currently support to do this through the Scottish Government’s Preparing for Sustainable Farming (PSF) initiative*, although this is due to end on 31 December 2025.
The full case study is available to view on the Peatland ACTION website at https://www.nature.scot/doc/peatland-action-case-study-investigating-peatland-restoration-and-liver-fluke.
Left to Right
- A liver fluke under the microscope. © Sinclair Stammers, MicroMacro
- A tiny mud snail (Galba truncatula) – the host that spreads the liver fluke © Philip Skuce/Moredun Research Institute
- Philip Skuce and Gillian Mitchell searching for mud snails. © Philip Skuce/Moredun Research Institute
NatureScot Peatland ACTION
As part of the Scottish Government’s Peatland ACTION Partnership, NatureScot Peatland ACTION currently funds up to 100% of the costs of peatland restoration, as well as providing advice, training and support to design, develop, deliver and monitor the projects. Applications are considered annually on a competitive basis to ensure the funding delivers as many hectares of restored peatlands as possible, with the best value for money. To support long term management, many of the projects are also being progressed through the Peatland Code. There’s more information at www.nature.scot/peatlandaction or contact peatlandactionmedia@nature.scot
