IT'S WET and it's mild - the ideal conditions for the snail that causes liver fluke to survive the winter and cause real issues in the spring for Scottish livestock, according to NADIS' latest health bulletin.

Liver fluke infection is reckoned to cost the UK cattle industry £23m in lost revenue.

This is a mixture of the cost of liver condemnation, poor growth, lower lactation and reduced fertility in cattle. Sheep are similarly affected.

NADIS (the National Animal Disease Information Service) provides this quick guide to the disease and its devastating effects:

LIVER FLUKE (FASCIOLOSIS)

Fasciola hepatica infects the liver of cattle and sheep. The incidence of liver fluke increases after a wet summer season.

CLINICAL SIGNS:

Persistent diarrhoea

Chronic weight loss

Poor body condition score despite an adequate ration

'Bottle-jaw', which is rarely seen in cattle

Severe infections may cause anaemia

DIFFERENTIAL DIAGNOSES:

Your veterinary surgeon will also consider:

Poor nutrition (whole group/herd problem)

Johne's disease (several cows in the group/herd)

Salmonellosis (several cows in the group/herd)

Parasitic gastroenteritis (whole group/herd problem)

DIAGNOSIS:

Acute disease - raised liver enzymes in blood collected by your vet.

Chronic fasciolosis - demonstration of fluke eggs in faecal samples

Specific antibody tests for liver fluke infestation

TREATMENT:

Triclabendazole is effective at killing all stages of flukes

Nitroxynil and oxyclosanide can be used in the treatment of chronic fasciolosis (adult flukes) which is the most common problem in cattle

Treated cattle should be moved to clean pastures wherever possible

Improved nutrition of affected cattle is essential

Cattle housed for more than six weeks can be treated with closantel or nitroxynil

PREVENTION/CONTROL:

Strategic flukicide treatments as detailed in the veterinary herd health plan

During low risk years treatment is given to at risk cattle in January

In years when epidemiological data indicate a high risk of fasciolosis, additional triclabendazole treatments may be necessary in October/November

Fencing off snail habitats is rarely practicable

Drainage is cost prohibitive and many properties are subject to environmental controls.

Control disease in sheep if present on farm

WELFARE IMPLICATIONS:

Debility, possibly leading to recumbency in heavily-pregnant cows, is a serious welfare concern.