Neurological disease produced by maedi–visna and caprine arthritis–encephalitis viruses, lentiviruses of sheep and goats

• Main Authors: Andrésdóttir, Valgerdur, Torsteinsdóttir,, Sigurbjörg, Georgsson, Gudmundur
• Format: Book Part
• Language: English
• Published: Oxford University PressOxford 2005
• Subjects: Pálsson; Iceland
• Online Access: http://dx.doi.org/10.1093/oso/9780198526100.003.0025; https://academic.oup.com/book/chapter-pdf/52513480/isbn-9780198526100-book-part-25.pdf

Abstract Maedi and visna are diseases that were brought to Iceland with the importation of apparently healthy sheep of the Karakul breed in 1933. Maedi (an Icelandic word for dyspnea) is an interstitial pneumonia, and visna (meaning wasting) is an encephalomyelitis. Epidemiological studies suggest that, of the 20 sheep that were imported, two were healthy carriers, one giving rise to an epizootic of maedi in the northern part of the country, the other causing an epizootic of both maedi and visna in the south-west part of the country. Due to the long preclinical period and the insidious onset of maedi and visna, the diseases had spread unnoticed to many flocks when first recognized 6–7 years after the importation (Pálsson 1976).