Are you getting the most from your winter fluke treatment?

The decision when to give fluke treatment depends on several factors but getting it right can have a real impact on growth rate and time to finishing.

That means using the right product, at the right time, using the correct dose and administering it in the right way. Unfortunately, no one treatment in isolation will kill all stages of fluke without consideration of the timing.

Two main aims for treating animals for fluke at or during housing:

• To remove the burden picked up from the pasture during the months before housing, when the levels of infectious stages of fluke are likely to be increasing. By removing this burden when housed, it will help the cattle to perform well over winter and achieve their full growth and productivity potential.

• To prepare for the next grazing season by removing all fluke prior to turnout ensuring there will be no adult egg-laying fluke inside the animal, reducing infection pressure the following season.

Choosing an appropriate product is critical and there are several factors to consider:

• Delaying treatment or not treating for all stages of fluke can have implications on growth rates and pasture infection levels for the following season. It is important to discuss with your vet or Registered Animal Medicines Advisor (RAMA) an appropriate strategy for your herd.

• The stage of fluke present in cattle at the time of housing - the NADIS fluke forecast, and farm history will help. Generally, in late summer or autumn, there will be increasing levels of infective fluke cysts on pasture with newly acquired, immature fluke within the cattle liver. However, a later housing period following a drier and colder autumn could mean that the majority of fluke present at housing are late immature or adult. Unlike sheep, cattle do not suffer from acute disease caused by early immature fluke, and the later stages of fluke have most impact on their growth and productivity.

• Products containing triclabendazole are key in preventing and treating acute fluke disease in sheep. With reported resistance in both sheep and cattle, careful consideration should be given to avoid overuse and further selection for resistance.

• Meat/milk withdrawal periods.
• Worming treatment - Is a combination treatment for worms and liver fluke required?

Should we test for fluke before treating at housing?

If you are concerned about liver fluke, your vet will be able to discuss farm-specific risk factors and carry out diagnostic tests to determine whether fluke is a risk to your herd.

Abattoir/post-mortem feedback will provide a definitive diagnosis or tests can be performed on blood or faeces.

Blood tests can be used to look for indicators of liver damage or determine if an animal has previously been exposed to fluke, whereas faecal tests can look for eggs shed by adult fluke in the chronic stages of disease.
Modern faecal tests can be used to identify fluke infections from five to six weeks after they enter the liver.

1. Mazeri et al, Nature Scientific Reports, 7: 7319, 2017.