Schmallenberg Virus
Schmallenberg virus (SBV) is a disease that affects sheep, cattle, and goats. It was first identified in Europe in 2011 and is spread by biting midges (Culicoides species). The virus is named after the German town where it was first discovered. SBV can cause significant issues in pregnant ewes, leading to abortions and deformities in lambs
Symptoms and Diagnosis 🩺
Symptoms in Adult Sheep
Adult sheep generally do not show any clinical signs of SBV. However, the virus can cause severe problems in pregnant ewes and their lambs.
Symptoms in Lambs
The most significant impact of SBV is on lambs born to infected ewes. Symptoms in lambs include:
- Abortion or stillbirth
- Severe malformations such as bent limbs and fixed joints (arthrogryposis)
- Brain deformities (hydranencephaly)
- Spinal cord abnormalities
- Neurological signs like blindness, ataxia, and inability to suckle
These deformities can lead to lambing difficulties and may require veterinary intervention, such as a caesarean section.
Diagnosis
Diagnosis of SBV can be challenging as not all affected lambs will test positive for the virus at birth. Blood tests can be conducted to determine exposure and susceptibility of the flock.
Treatment 💊
Unfortunately, there is no specific treatment for SBV. Supportive care for affected lambs and veterinary assistance during difficult lambing can help manage the condition. Severely deformed lambs may need to be euthanized for welfare reasons.
Prevention 🛡️
Vaccination
While vaccines were developed after the initial outbreak, they are not currently commercially available. Vaccination, when available, can help protect the flock.
Managing Midge Exposure
Since SBV is spread by midges, reducing midge exposure is crucial. This can be done by:
- Applying insecticides to reduce midge bites
- Shifting mating seasons to avoid peak midge activity
- Monitoring midge populations and taking preventive measures accordingly
However, controlling midge populations on a large scale has proven difficult.
Biosecurity Measures
Implementing strict biosecurity measures can help prevent the introduction and spread of SBV. This includes:
- Quarantining new animals
- Maintaining clean and hygienic environments
- Keeping records of animal movements and health status
Consult your veterinarian for specific advice tailored to your farm's needs.
Conclusion
Schmallenberg virus is a significant concern for sheep farmers, especially during the lambing season. By understanding the symptoms, implementing preventive measures, and working closely with your veterinarian, you can help protect your flock from this disease.