54. Border disease of sheep.

Question 1

History, Occurrence?

Answer 1

“Foetopathogen infection of pregnant ewes characterised by retarded development & CNS damages of the

Lambs”

History, occurrence

• First description in the border region btwn England & Wales
• World-wide distributed
• In Hungary: approx. half of the herds are infected, seropositive animals in herds: 3-35%

Question 2

Causative agent?

Answer 2

Causative agent:

Flaviviridae, Pestivirus, Border disease virus(BDV)

• Closely related to the BVDV
• BVDV strains can also cause disease in sheep similar to the border disease
• Rarely infects goat too

Question 3

Epizootiology?

Answer 3

Epizootiology

• Reservoirs: persistently infected animals (sheep, cattle, wild Ru)
• Horizontal & vertical spread

Question 4

Pathogenesis?

Answer 4

Pathogenesis

• Similar to BVD
• Manly abortions in the 1st half of the pregnancy
• Mainly foetopathy (epithel, nervous tissue) in the second half of the pregnancy
• Immuntolerance, later immune response

Question 5

Clinical signs?

Answer 5

Clinical signs

• Weak lambs, hair-like, pigmented wool, usually on the neck &back
• Ataxia, trembling (hairy shaker)
• Cranial developmental problems
• Retarded growth, high lethality
• Ewes show no signs, post-partum infections are subclinical

Question 6

Diagnosis and prevention?

Answer 6

Diagnosis:

BVD differentiate

Prevention:

• selection of carrier animals,
• separation, closed farming