Many people will routinely treat for liver fluke early in the autumn, or as soon as the NADIS parasite forecast recommends.
However, Fluke Sentinel, a survey done by XL Vets in 2019 showed surprising results. Out of 24 participating “flukey” farms, only 11 showed fluke exposure in lambs in the period from June to December. Most of these showed up later in the year, with only one or two lambs out of the six testing positive. Even farms located reasonably close by showed positive cases months apart.
Testing before treatment can preserve flukicide efficacy.
Triclabendazole (TCB) is the only treatment able to kill all life stages of the parasite. Without TCB, we will struggle to control the damage caused by juvenile liver fluke infections. There is now firm evidence that resistance to this flukicide is developing, including locally. By treating only when there is evidence of infection, we will reduce the number doses given, and the opportunity for liver fluke to evolve resistance.
Testing before treatment can save money.Fluke Sentinel suggested there is a case to be made for a much more targeted approach to treatment with flukicides. Routine treatment in the autumn may be a waste of money and time in a busy part of the year. Remember that fluke treatments are not long acting. If stock are treated before peak infection has occurred and they remain on infected (flukey) pasture, they are still at risk.
Each farm is different. Weather patterns are becoming increasingly more variable. The fluke risk is changing each year. Monitoring the situation on an individual farm can help save money by eliminating unnecessary treatments.
COWS/SCOPS experts suggest you use this season’s lambs or calves as sentinels and test them using a blood test before considering treatment of the rest of the group. Blood testing will identify a liver fluke burden much earlier than dung testing. The test is relatively inexpensive, is accurate and can detect antibodies from 2 weeks after fluke infection. Samples can be taken by our Vet Tech team,
either on farm or at the surgery (sheep).
• Speak to your vet to arrange the test and to help interpret the results.
• Knowledge of the farm’s history for liver fluke will also be useful.
• Test six to ten sentinel lambs/calves every month. While these results are negative, there is no need to treat for fluke. If positive results are found, speak to your vet about further testing with a copro-antigen test if needed. Once confirmed as infected then you should treat the rest of the group.
• If treatment is necessary, treat with a product to target the immature stages of fluke such as triclabendazole, closantel or nitroxynil.
• If your farm has an issue with triclabendazole resistance, then avoid using this.
• Avoid turning animals back onto
flukey pastures if possible, to avoid re-infection and further risk of disease.
Don’t forget store animals
Discuss quarantine dosing with your vet.
Appropriate treatments will depend on the age of the lambs/calves, time to finish and time of year.
When dosing, always remember the COWS/SCOPS 5 R’s:
Use the right product, treat the right animal, at the right time with the right dose in the right way.
More information can be found on these websites:
SCOPS – www.scops.org.uk
COWS – cattleparasites.org.uk/
NADIS – https://www.nadis.org.uk/disease-a-z/sheep/liver-fluke-control-in-sheep/
XL Vets – https://xlvets-farm.co.uk/fluke-sentinel
Checking for fluke in any dead stock is a cheap and easy way of monitoring for liver fluke. If the carcase is reasonably fresh, cut it open and examine the liver.
Make several cuts into the liver. If you have a smart phone in your pocket, take some pictures and we can provide a second opinion by email.
Abattoir feedback on livers can be useful, but remember that affected animals are less likely to reach slaughter weight early.