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Schmallenberg virus (SBV) affects ruminants such as sheep, cattle and goats, and camelids.

First published:
19 November 2018
Last updated:

Identified in Europe in 2011, the virus is spread by biting midges and was first detected in the UK in 2012. It does not infect humans and there is no risk to public health or food safety.

SBV is not notifiable in the UK and no restrictions are placed on premises where SBV is present.

Suspicion and confirmation

If you suspect infection with SBV in your livestock please talk to your private veterinary surgeon. In sheep and cattle, lambs and calves can be born with congenital deformities. These can be also characteristic for other diseases such as Bluetongue, which is a notifiable disease. If you suspect presence of notifiable disease, then contact the Animal and Plant Health Agency (APHA) immediately on 0300 303 8268. 

Clinical signs

The acute disease usually lasts between 2 and 7 days in adult animals, before they begin to develop robust immunity. Cattle can present with mild symptoms which can include:

  • milk drop
  • fever
  • diarrhoea

In sheep, clinical signs of SBV are often mild or absent.

Schmallenberg virus can be transmitted to a foetus from an infected pregnant animal. This can lead to abortion and malformations of the foetus. Calves and lambs can be born small, weak, deformed or blind, and die within a few days of birth. Malformations observed include bent limbs and fixed joints, brain deformities and damage to the spinal cord.  

Examples of differential diagnosis:

  • Bluetongue 
  • Bovine Viral Diarrhoea
  • Border Disease

Transmission and prevention

Schmallenberg virus is spread by infected midges.  These insects could continue to spread the disease in the UK also through autumn and winter.

Malformations affecting lambs and calves exposed to the virus in pregnancy may lead to lambing or calving difficulties. Please contact your private veterinary surgeon for advice.

Good biosecurity practices should be followed. This includes the single use of needles and good disinfection procedures when dealing with products of afterbirth.