Experts warn of frightening sheep liver fluke levels

FRIGHTENING levels of liver-fluke infection in sheep in Scotland could be just the “tip of the iceberg”, according to vets from SAC Consulting, a Division of Scotland’s Rural College.

Infection by the fluke parasites causes ill health, decreased fertility, lower productivity and even death. With wet weather causing a dramatic rise in reported cases this year, farmers and crofters are urged to act now to ensure the safety of their flock.

Between October and December last year there were more than 200 cases of live fluke recorded by SAC Consulting, Veterinary Services. In the same period in 2011 there were only 57 cases. Brian Hosie, veterinary services group manager believes many more cases were dealt with by farmers who did not bother to report them.

He said: “These cases are probably only the tip of the iceberg. This massive increase in liver fluke is a consequence of the wet summer and mild winters we have had in recent years. It is impacting on the viability of many sheep farms through reduced productivity and high death rates in flocks.”

The liver fluke parasites attack the liver of many mammals but mostly affect sheep and, to a lesser extent, cattle. Eggs from infected stock fall on pasture and once hatched, find a mud snail in which to live and multiply. On leaving the snails they climb on to grass, are eaten by livestock, migrate to the liver and cause tissue damage. Acute cases can kill, while even milder cases can adversely affect condition and fertility. The parasite also makes infection by other conditions, such as black disease, more likely.

The extremely wet Scottish weather of the last two years has provided ideal conditions for fluke larvae to spread and the mud snails to flourish and multiply.

Brian Hosie stresses that farmers must act quickly to diagnose and then treat any cases of liver fluke.

He added: “Failure to take action in the next few weeks could result in serious losses at lambing time through weak ewes dying or having insufficient colostrum to feed their lambs. These lambs may die of starvation or from diseases such as joint ill or severe diarrhoea”.

Early pregnancy scans have detected significant numbers of barren ewes, without lambs, which could be linked to the rise in fluke infections.

SRUC sheep specialist John Vipond warns farmers to look out for signs that ewes are unfit, which could indicate infection. Sheep may have a poor fleece, break back when walked up a hill, or not come forward for feeding.

Dr Vipond also urges farmers to take preventative measures such as fencing off particularly wet areas which will host more snails, improving field drainage or moving flocks to drier fields, where possible.

Another worry for sheep farmers is the reported resistance to medicines that some animals seem to be developing.

While many farmers are very worried about their stock and the frightening statistics the experts from Scotland’s Rural College (SRUC) emphasised that most animals will recover completely after treatment. However, they will need some extra care and attention, such as an earlier move indoors and good nutrition.