Veterinary Services

• Black disease, malignant oedema and blackleg in cattle confirmed
• Botulism diagnosed in an Aberdeen Angus cross heifer
• Copper, cobalt and selenium deficiencies associated with ill thrift in lambs
• Review of cases of fasciolosis in cattle and sheep 1993 to 2008
• Deaths in weaned pigs due to Streptococcus suis serotype 2

Disease alerts

The following conditions featured in the SAC report for November 2007. Given similar climatic and husbandry conditions, they could also be important this year.

• Cases of acute liver fluke disease in sheep and chronic disease in cattle
• Outbreaks of respiratory disease in cattle at start of housing period
• Systemic pasteurellosis in sheep
• Heavy mortality due to salt poisoning in grower and finishing pigs fed concentrated whey

Liver Fluke

An unprecedented rise in the prevalence of fasciolosis in sheep and cattle in Scotland is found on examination of diagnostic data recorded by SAC VS over recent years (see Figure 1 - see top right-hand side).  This increase was associated with a general tend towards increased temperatures and higher levels of rainfall.  As a result, the disease has spread to many previously unaffected areas, particularly in eastern and central Scotland.  The number of farms on which flukicide resistant flukes were detected in sheep has also increased since this was first detected in Scotland in 1998. Clinical disease and deaths in sheep are often seen either as acute disease (Figure 2 - see top right-hand side) associated with the migration of immature flukes through the liver parenchyma or as chronic disease (Figure 3 - see top right-hand side) associated with adult flukes in the bile ducts.

In 2003 as a response to the emerging problem and its threat to animal welfare, SAC Veterinary Services, with Scottish Government funding commenced a national liver fluke campaign.   This campaign was aimed at increasing awareness of fasciolosis, its treatment and control.  Subsequent SAC disease surveillance figures showed that the number of outbreaks in sheep fell, although infection in cattle remained high. 

In 2008, following successive summers with higher than average rainfall,  the risks of fasciolosis outbreaks during the forthcoming autumn and winter months remains severe.   Farmers have once again been advised to assess the risk of disease to their animals and to take advice from their veterinary advisors on suitable liver fluke control.

GENERAL INTRODUCTION

Scotland had the dullest August since 1978 with barely 97 hours of sunshine.  It was also very wet with 144 per cent of the thirty year rainfall average falling. The mean temperature was however one degree Celsius above the average.

SAC considered these conditions likely to favour the development and survival of parasitic larvae on pasture.

Farmers were reminded to remain vigilant when sourcing animals during the approaching livestock sales season. The Scottish Government issued specific advice on selling and buying livestock in relation to preventing bluetongue disease spread.

The Scottish Government also announced a one million pound package of support for the pig industry. This included future research on post-weaning multi-systemic disease syndrome.

SAC published a report highlighting the dramatic decline in sheep numbers in the Scottish hills. Many areas have seen a reduction of between 35 and 65 per cent since 1999. The report "Farming's Retreat from the Hills" is available to view using the link on the right.