[Border disease: a persistent virus infection in sheep (author's transl)].
Border disease (BD) is a congenital infection of sheep characterised by still-birth, abortion and the birth of weak lambs with nervous symptoms and sometimes an abnormally hairy birthcoat. The lambs are almost constantly trembling or shaking, they often have an erratic gait and in severe cases are unable to rise. The nervous signs are due to a defective myelinogensis of the central nervous system and tend to disappear at a later age. Many affected lambs die shortly after birth and those which survive usually show retarded growth. The disease is caused by a virus which is closely related to the virus of bovine virus diarrhoea (BVD). The virus may be isolated from every organ and is excreted with saliva, nasal discharge, urine and faeces. Clinically the diagnosis can be made with high probability when nervous signs and hairy birthcoat are both present. Laboratory diagnosis is based on the detection of antigen by immunofluorescence or virus isolation. In addition ewes of BD-affected lambs usually possess antibodies against BVD-virus. In some lambs, an immune response starts during prenatal life, others show a transient or lasting low level response at a later age, whereas still others remained serologically negative for at least 2 1/2 years. Asymptomatic virus carriers occur among lambs as well as among adult sheep. The persistently infected animals are continously shedding virus and thus maintain the infection in the flock.
D000818:Animals; D000956:Antigens, Viral / Q000302:isolation & purification*; D002353:Carrier State / Q000662:veterinary; D001908:Diarrhea Viruses, Bovine Viral / Q000276:immunology*; D005260:Female; D008431:Maternal-Fetal Exchange; D010576:Pestivirus / Q000276:immunology*; D011247:Pregnancy; D012756:Sheep; D012757:Sheep Diseases / Q000151:congenital / Q000382:microbiology*
D000956:Antigens, Viral
Border disease: een persisterende virusinfectie bij schapen.