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Diagnosis of the nervous form of maedi‐visna infection with a high frequency in sheep in Castilla y León, Spain
Author(s) -
Benavides J.,
Gómez N.,
Gelmetti D.,
Ferreras M. C.,
GarcíaPariente C.,
Fuertes M.,
GarcíaMarín J. F.,
Pérez V.
Publication year - 2006
Publication title -
veterinary record
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.261
H-Index - 99
eISSN - 2042-7670
pISSN - 0042-4900
DOI - 10.1136/vr.158.7.230
Subject(s) - meningoencephalitis , ataxia , paresis , central nervous system , immunohistochemistry , encephalitis , pathology , nervous system , medicine , biology , virus , virology , surgery , psychiatry
Between 1997 and March 2004, the nervous form, or visna, of maedi‐visna infection was diagnosed in 71 of 1631 sheep (4·35 per cent) examined in the Castilla y León region of Spain, of which 634 had shown nervous signs. The presence of the virus was confirmed by immunohistochemistry and in some cases by PCR on frozen‐thawed or paraffin‐embedded tissue samples. The main clinical signs were hindleg ataxia and paresis, but blindness or nystagmus were also observed. Thirty‐three of the affected sheep (46·5 per cent) were two years old or younger. The affected sheep showed variable degrees of a non‐suppurative meningoencephalitis, and immunohistochemistry identified positive cells in all cases, with no relation to the intensity of the inflammatory lesion.