Ayr-based SAC vet Dr George Mitchell said: “Outbreaks of acute liver fluke in sheep, leading to death, have recently been recorded in Ayrshire. This would indicate local conditions have been right for the development of the parasite within its host, the mud snail Galba truncatula. Therefore it is essential that sheep and cattle perceived to be at risk in these areas are treated. But farmers across Scotland should remain vigilant.

“Any casualty animals should be submitted to SAC Veterinary Centres for post mortem examination to establish a cause of death and to permit continual monitoring of the prevalence of liver fluke disease in cattle and sheep.”

Both rainfall and temperature have an effect on liver fluke infection levels. The parasite’s host, the mud snail, lives in wet habitats. Due to this year’s higher average rainfall, such wet habitats have been around for longer and are more widespread due to flooding.

While this would suggest that the snail, therefore the parasite, would flourish, temperatures have been on average 1C lower this year than in 2010. Dr Mitchell believes this could be the reason for this year’s drop in liver fluke cases.

He said: “The summer of 2003, following which Scotland’s highest levels of liver fluke disease were recorded, had above average temperatures and below average rainfall suggesting that temperature rather than rainfall may have a greater influence on the level of disease.

“The slightly lower temperatures this year may have slowed the liver fluke parasite’s development within the snail. This may reduce the number of immature flukes emerging from snails this autumn and through the winter, which will determine the level of acute and chronic liver fluke disease suffered by our sheep and cattle in the coming months.”

Those seeking further information and advice on liver fluke should contact their local SAC Veterinary Centre.