Schmallenberg Surveillance Results Out
No virus found as cold temperatures limit spread
The first round of Schmallenberg surveillance testing in Scotland is almost complete with no positive samples identified.
NFU Scotland, working with SRUC and Biobest, has established a network of dairy farms across the whole of Scotland where bulk milk tanks are being tested on a month basis for the presence of Schmallenberg Virus (SBV) antibodies. To date 91 tests have returned negative with five test results still outstanding. Testing will be repeated again in June and July.
Spread by midges, SBV was first identified on German and Dutch farms in 2011 and has since spread throughout Europe and other parts of GB. Five cases have been confirmed in Scotland and there is the widely held expectation that the virus will start to circulate here in 2013.
Exposure to SBV can result in relatively mild conditions in cattle and sheep but where infection takes place during the early stages of pregnancy; it can result in congenital disorders of lambs and calves. Infection may also be linked to poor breeding performance.
With bulk milk samples testing negative for antibodies to the virus, it suggests spread in Scotland to date has been limited and cold temperatures are likely to have had an impact on the activity of both midges and the virus. However, a period of warmer weather could change that picture in a relatively short space of time and livestock keepers are urged to remain vigilant for signs of the disease and to discuss their breeding plans with their vet.
NFU Scotland’s Animal Health Policy Manager, Penny Johnston said:
“We know the disease has arrived in Scotland but with bulk milk samples testing negative for SBV, it suggests that the virus may have crept into the country at the end of last year when temperatures were falling, cattle had been housed for the winter and midge activity was low.
“The ongoing low temperatures may prove to have had a limiting effect on further viral spread in recent months but an upturn in temperatures could very quickly change that picture. That is where our surveillance is crucial in mapping the speed at which the virus starts spread and its likely reach across Scotland.
“The virus could start to shift in the next few months and we continue to urge all livestock producers to discuss the implications for their stock with their vet.
“The virus seems to be able to cope well with our climate and there is a risk that spring calving cows in the southern half of Scotland could be challenged by the virus during the danger period of the breeding cycle.
“It is also expected that vaccination will soon be an option for cattle and sheep producers to consider when it comes to protecting stock. These are the kinds of discussions that our farmers now need to have urgently with their vets.”
Notes to editors
- Schmallenberg Virus (SBV) is a virus that was first identified in Europe in 2011. It affects sheep cattle and goats and is spread by midges. The acute, active phase of the infection presents with fairly mild symptoms, typically diarrhoea, fever and milk drop with a rapid recovery over several days. There may be some accompanying drop in fertility associated with this stage.
- If infection occurs during the early stages of pregnancy, between 25-50 days for sheep and 70-120 days in cattle, abnormalities can occur in the foetus that may be born alive or dead or it may be aborted. Malformations can include bent limbs and fixed joints, twisted neck or spine, a domed appearance to the skull, short lower jaw and brain deformities. Some animals are born looking normal but have nervous signs such as blindness or a dummy presentation – uncoordinated movement, recumbency, an inability to suck and sometimes convulsions.
- Farmers are advised to contact their veterinary surgeon if they encounter any of the symptoms of either the acute stage of the disease or malformed foetuses and abortions.
Ends
Contact Bob Carruth on 0131 472 4006
Date Published: 15/05/2013
News Article No.: 68/13
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