Beef and dairy farmers are being urged to consider the risk of liver fluke infection this autumn and, if indicated, to treat cattle appropriately.
An industry stakeholder group that aims to promote best practice in the control of cattle parasites is urging beef and dairy farmers to consider the risk of liver fluke infection this autumn and, if indicated, to treat cattle appropriately.
However, the Control of Cattle Parasites Sustainably (COWS) group has warned that liver fluke take approximately 10-12 weeks to mature following ingestion of infective stages and not every type of flukicide is fully effective against all immature stages – hence it is important to choose an appropriate product and to administer it at the correct dosage at the most suitable time of year according to the life cycle of the parasite.
The COWS group is strongly advising that farmers discuss product choice with their vet or suitably qualified person (SQP) as part of their herd health plan.
Choice of drug will be influenced not only by risk of infection, but also by its meat/milk withdrawal, risks posed by other parasites that may be present and ease of administration. The table below summarises the main treatment options in relation to when they are best used post-housing.
|Active ingredient||Administration route||Stage of fluke killed||Best time for treatment after housing|
|Triclabendazole||Oral||2 weeks onwards||From 2 weeks|
|Pour-on||6-8 weeks onwards||From 6 weeks|
|Closantel||s/c injection or pour-on||7 weeks onwards||From 7 weeks|
|Nitroxynil||s/c injection||8 weeks onwards||From 8 weeks|
|Clorusulon||s/c injection||Adults only||From 12 weeks|
|Oxyclozanide||Oral||Adults only||From 12 weeks|
|Albendazole||Oral||Adults only||From 12 weeks|
According to the COWS group, if fluke risk is high, treatment in the autumn with triclabendazole (which kills almost all stages of liver fluke) may be appropriate, as long as there is no evidence of resistance to this drug. If the risk of infection is lower, then anthelmintics with activity against late immature/adult fluke stages can be used later in the season (December/January).
If cattle are dosed around housing time, use faecal egg counts in late winter to see if a second dose is needed to remove any fluke that were too young to be killed by the first treatment. A product that targets adult fluke can be used at this time.
A limited range of products can be used in dairy cattle. COWS suggests treatment at drying off be considered if there is evidence of infection in the herd and that consideration should be given to the time of year (highest levels of infection typically occur on grass in autumn) and if cows are housed or out at pasture during their dry period.
The group also stresses that no flukicide has persistent action. If cattle are housed after treatment, then there is a very low risk of picking up new infection until they are turned out again, but allowing cattle onto fluke infected pasture after treatment immediately re-exposes them to the risk of infection. So, if turning animals back out after treatment, use tactics such as moving to “low risk” areas or fencing off risky areas. If cattle must remain in risky areas, then monitoring for infection is essential as further treatments may be needed.
- COWS aims to provide the best available, evidence-based information to the cattle industry in relation to the sustainable control of parasites in dairy and beef cattle.
- COWS’ Top 10 Tips for Controlling Liver Fluke in Cattle can be found at www.cattleparasites.org.uk, along with details of flukicide products for cattle including information on active ingredient, stage of fluke killed, route of administration and withdrawal period.