Schmallenberg still a threat
First identified in Ireland in October 2012, Schmallenberg still remains a threat to Irish sheep flocks and cattle herds.
As part of a recent Let’s Talk Sheep Webinar, Audrey Jenkinson, a Superintending Veterinary Inspector with the National Disease Control Centre at the Department of Agriculture, Food and the Marine, provided an insight into Bluetongue and Schmallenberg disease.
Presenting information provided by her colleagues in the Regional Veterinary Laboratories, Audrey Jenkinson noted that there was evidence that the Schmallenberg virus was circulating in Ireland in mid to late 2024. Additionally, as the population’s immunity generally wanes after 5-7 years and no vaccine is currently available, the disease still poses a risk.
“The trouble with Schmallenberg is that it can cause birth deformities, but by the time those lambs or calves are then born, the detectable traces of the virus could be long gone,” she noted.
In sheep, it is known to cause abortion and deformed lambs. The congenital deformities which occur include: twisted neck, maybe also ‘locked’; limbs bent and locked; shortened lower jaws; and abnormalities with excess fluid in the brain.
On the likelihood of the disease occurring this spring, Audrey Jenkinson said: “Our lab colleagues expect that there could well be significant Schmallenberg related losses on some farms this spring.”
Although some farms will see no cases, she noted that estimates of up to 15% losses have been reported in the past.
What should farmers do?
The Superintending Veterinary Inspector urged farmers to vigilant for birth abnormalities. Extra care is also required in terms cleanliness, colostrum feeding and biosecurity, as evidence from France and the Netherlands suggests that some calves and lambs can be born perfectly normal, but with reduced viability.
She added: “Don’t assume an abnormality or abortion issue is Schmallenberg because there is so many other diseases that can cause these things.” And, she urged farmers to continue to submit samples to their local Regional Veterinary Lab, ideally fresh carcasses with afterbirths and maternal bloods, in order to have the best chance of getting a diagnosis.
For further details, the full recording of the Let’s Talk Sheep Webinar is available to view below: