XLVets Fact Sheet

Liver Flukein Cattle

XLVets Committed to UK farming

Fluke infection has been recognised for generations, but evolving problems in cattle demandwe look afresh at how liver fluke might be undermining herd performance. Over the past yearsthere has been an alarming increase in the incidence of liver fluke. This has coincided with agreater geographic distribution beyond the traditional at-risk, high rainfall areas.

Sheep are particularly susceptible tofluke. Infection can cause serious illness,even death. However fluke is often over-looked in cattle because the signs arevery subtle and clinical disease is rare.

Just because there are no signs or the farm has never traditionally hadfluke, it does not mean that cows andyoungstock will not benefit from a fluke control strategy.

CONSEQUENCESA low grade infection of just 100 flukehas been shown to reduce milk yieldby 400litres/cow/lactation. For a 100-cow herd at 18ppl this equates to £7,200 p.a.

Fluke has a detrimental effect on butterfat. Research has shown untreated animals can produce 10% less milk solids.

Heavily pregnant dry cows in poorbody condition can experience a fluke-associated nutritional challenge in late pregnancy.

Calf birth rates for fluke-infected cowscan be 10% lower.

Youngstock will experience poorergrowth rates giving reduced efficiencyfor the rearing of replacement heifers.

Fluke infection can reduce feed conversion and depress appetite (DMintakes reduced by as much as 11%).This nutritional stress depresses fertility and compromises the cow'simmune status.

In essence fluke infection can reducelifetime performance.

Fluke infection can also precipitateother infectious disease such as theClostridial infection ‘Black disease’ or it can compound outbreaks ofSalmonella.

Many farmers see the need to treatfor fluke infection in sheep wheresymptoms can be more graphic, yetfail to recognise the production loss in cattle.

The main signs are a reducedgrowth rate, a gradual depressionof milk yield, and stock that aregenerally not thriving.

SIGNS OF LIVERFLUKEINFECTION

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Parasitic Diseases PPDD

XLVets Liver Fluke in Cattle

XLVets Committed to UK farming. Go to www.xlvets.co.uk

Liver FlukeLife CycleLiver Fluke (Fasciola hepatica) is aflat leaf-like (3.5cm) parasite found in the liver of grazing animals. Eggsfrom adult female fluke pass in thedung to contaminate pasture.

When conditions are suitable - dampand warm (above 10%) - the eggsevolve and hatch to form mobile larvae that seek out mud snails tocomplete their life cycle.

The presence of the amphibious mudsnails determines the distribution of

fluke. So the highest risk grazing arewet areas and around rutted pools.

The larvae multiply in the snails andemerge to attach to the grass as cysts.The grazing animal ingests the cystwhere it breaks out as an immaturefluke to make its way to the liver.

The fluke tunnel through the liver and ifconditions favour, then a mass hatchand infection can cause severe andpermanent damage.

The adult fluke live in the bile ducts ofthe liver where they feed on blood. Thiscan amount to half a millilitre per adultfluke per day explaining the anaemiaexhibited by infected animals.

DIAGNOSISFluke diagnosis is not straightforward and needs careful interpretation, so speak to yourvet.

Fluke egg counts from faecal samples indicate infection but egg production is sporadic.

Blood sampling a random group(young homebred stock would beare a good indicator) can revealthe foot-print of fluke infection.

Post mortem/slaughterhouse feedback provides a direct report of fluke level in condemned livers. Many moreabattoirs are doing this now.

Treatment is very effective butneeds to be targeted to the flukeseason and to recognise the variable efficacy of product for thedifferent stages of fluke (earlyimmature, immature and adult).

Also the milk withhold must be con-sidered and often means treatmentis targeted in the dry period. Fluketreatments come as drenches andinjections and are also available incombination with wormers. The

recognition of fluke and a strategicapproach to treatment should be acomponent of herd health planreviews. A little investment inhealth will go a long way to alleviating the production loss.

TREATMENT

Parasitic Diseases PPDD

XLVets is a nationwide group of independently owned,progressive veterinary practices committed to the futureof the UK livestock industry. We work together to defineand continually develop veterinary practice standards.

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