Border disease

Also known as hairy shaker disease


Description

Border disease is caused by a Pestivirus (Flaviviridae) infection of the foetus in early pregnancy. Infection of naïve, pregnant ewes can lead to placentitis, foetal death, and abortion. Affected lambs are born 2-3 days prematurely and many die before or at weaning. Surviving hairy shaker sheep remain infected and excrete the virus throughout their lives.

Border disease or hairy shaker disease is a congenital disorder of lambs and outbreaks of infertile ewes and abortion.  Affected lambs are undersized with extremely hairy coat and may exhibit involuntary muscular tremors, mainly of the trunk and hind limbs. The nervous signs gradually disappear in surviving lambs within 3-4 months of age. Other affected lambs can have skeletal defects such as dropped pasterns and mandibular brachygnathia.

Diagnosis and tests available

Diagnosis

Diagnosis is supported by history, clinical signs and the demonstration of Pestivirus in affected lambs and antibody in the ewe.

Tests available

Test

Sample(s) required

Days of the week test is conducted

Turnaround time1

Histopathology examination

Fixed tissue

Monday –Friday

Up to 2 weeks for brain samples. Up to 5 days for spinal cord samples.

Pestivirus antibody AGID

Whole blood (red top tube) or foetal fluid

Tuesday & Friday

3-5 days

Pestivirus antigen capture ELISA (PACE)

Whole blood (red top tube), lithium heparin blood (green top tube) or EDTA blood (purple top tube)

Batch tested 2-3 times weekly

5-7 days

Pestivirus PCR

Whole blood (red top tube) or EDTA tube (purple top tube)

According to demand

Up to 1 week

Pestivirus VNT

Whole blood (red top tube)

Batch tested on Friday

1-2 weeks

1 Turnaround times are provided as a guide only. For specific information about your submission please contact Customer Service.

Specimen requirements

Blood (with anti-coagulant)

  • 10ml of blood from the affected lamb and its mother collected in a lithium heparin treated evacuated tube
    • Submitted chilled
  • 10ml of blood from the affected lamb and its mother collected in an EDTA tube
    • Submitted chilled

Fixed tissue

  • Fixed brain and spinal cord
    • Submit fixed in neutral buffered formalin at a 10:1 ratio of formalin:tissue

Foetal fluid

  • Pericardial, pleural or peritoneal (in order of preference).
    • Submit chilled

Fresh tissue

  • Fresh lung, spleen and mesenteric lymph node
    • Collect aseptically and submit chilled
  • Whole lamb or foetus (and foetal membranes)
    • Submit chilled in an insulated container

Note

Heparinised blood from young animals (under 6 months of age) allows PACE analysis of the buffy coat without interference from maternal antibodies in the serum