2013-11-08  facebooktwitterrss
Get Fluke Treatment Right This Autumn

The Cows industry group is urging beef and dairy farmers to consider the risk of liver fluke infection this autumn and, if indicated, to treat cattle appropriately.

Risk factors include a previous history of fluke infection on the farm or farm of origin and grazing wet areas of pasture or near muddy areas, such as poached ground near gateways and troughs. Abattoir feedback provides very clear evidence of liver fluke infection, whereas diagnostic tests on blood and, on dairy farms, bulk milk tank samples can test for evidence of exposure and tests on dung will only work if adult fluke are present.

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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. It is important to choose an appropriate product and to administer it at the correct dosage and 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 Admin. route Stage of fluke killed Best time for treatment after housing
Triclaben
-dazole
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
Clorsulon s/c injection Adults only From 12 weeks
Oxyclozanide Oral Adults only From 12 weeks
Albendazole Oral Adults only From 12 weeks

 

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 time). 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.

COWS stresses that no flukicide has persistent action and allowing cattle onto fluke infected pasture after treatment immediately re-exposes them to the risk of infection. If cattle are housed after treatment, then there is a very low risk of picking up new infection until they are turned out again. 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

Related Links
link Single Injection for BVD and IBR Control
link G Shepherd Animal Health Launches Yolk-Ay Calf Paste
link Fluke Alert on Irish Farms
link Expert Group Advises on BVD Control Strategies
link Veterinary


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