Warning on liver fluke rise
THE PREDICTION by the National Animal Disease Information Service (NADIS) for a high risk of liver fluke disease in North, West and central Scotland, West Wales and Cornwall this winter have been borne out by incidences recorded over recent months.
Given the risk to both sheep and cattle, SCOPS and COWS have come together to remind producers that the high-risk warning followed a year with one of the wettest summers on record and higher than average rainfall in many parts of Great Britain. The risk in Eastern Scotland and parts of South West and Northern England is predicted to be medium and most of Central and Eastern regions of England were forecast to be at low risk.
Recent reports from members of SCOPS and COWS, including SAC Veterinary Services, APHA and others, support this general situation – but there are localised variations. This means it is very important that farmers talk to their vet, SQP or advisor to find out what is happening in their area, and decide what tests and risk assessment they need to carry out to investigate the situation on their own farm.
Now that we are into late winter, more cases of chronic and sub–acute liver fluke are being seen as the parasite matures in the host. Highlights of reports collated by SCOPS and COWS are as follows:
REPORTS FROM AROUND THE UK
In Scotland, SRUC report that in terms of liver fluke incidence as a % of total submissions, 2017/18 has been the highest winter level since 2012/13.
In Wales, numerous cases have been reported by APHA. In January and February, cases of chronic fluke in Western England and West Wales are reported.
In Cumbria, cases of sub-acute and chronic liver fluke have been reported with chronic liver fluke in North Yorkshire.
In the Bristol area, abortions in a flock have were associated with the presence of liver fluke disease.
A large Welsh abattoir reports a further increase in lamb liver condemnations due to fluke, rising from 2.8% in October to 5% in November and from 7.3% in January to 10.5% in February. This is significantly higher than the same month a year ago (7.8%) and underlines the fact that this winter is carrying a higher risk.
SCOPS and COWS provide this advice to producers:
Reports of disease continue mainly from high-risk areas, but farmers should seek local information, assess risk and use tests, abattoir feedback and post mortems to inform on-farm control measures.
Re‐infection (when treated animals are put back on to contaminated areas) is still a concern. Farmers need to remember that flukicides do not have any persistent activity. We also now need to be thinking about chronic / sub-acute disease as fluke mature and damage the liver.
Poor pregnancy scanning results in sheep may be the first indication that there is a liver fluke problem on the farm and may be limited to only one group of sheep depending on the group’s autumn/winter grazing history.
Make sure clostridial vaccinations are up-to-date. Black disease is a major cause of losses in cattle (and sheep) that have livers damaged by liver fluke.
While most cases of disease are associated with sheep, cases of liver fluke are being reported in cattle (11% of cattle submissions to SRUC have been associated with liver fluke disease this winter). It is essential that cattle farmers are aware of the risks and discuss sampling/testing/flukicide options for different stock with their vet to avoid disease.
Product choice is critical.
This latter part of the liver fluke season is the time to consider taking pressure off triclabendazole products and swap to alternatives. These include closantel, nitroxynil and products that kill adult fluke, such as oxyclozanide, albendazole (and clorsulon for cattle).
Note restrictions on the use of flukicides in milking cows.
The SCOPS website and COWS website have specific pages providing information on suitable products to use.