title: Impact of maedi-visna in intensively managed dairy sheep.
abstract: Maedi-visna (MV) is a slow lentiviral disease of sheep that has a significant economic impact in many sheep-producing regions although there remains a paucity of data relating to actual production losses resulting from this disease. The objective of this study was to evaluate direct losses, through death or culling, from two dairy sheep flocks with high seroprevalences of infection over a 2 year period. Maedi-visna was found, either alone or in combination with other diseases, to be the most common disease diagnosed in these sheep, and the major cause of direct animal losses in the two flocks. Moderate to severe lesions associated with MV were found in 52% and 80% of the sheep, respectively, affecting the lungs, brain and/or mammary glands. Despite the similarity of the two flocks under study in terms of breed, number of animals, geographical proximity, and inter-change of rams, a striking difference was observed regarding the clinical presentation of the disease: in one flock the respiratory form was dominant while in the other 70% of animals died or were culled because of neurological signs.
authors: Instituto de Ganadería de Montaña (CSIC-ULE), 24346 Grulleros, León, Spain. Electronic address: j.benavides@eae.csic.es.
authors: Julio
authors: J
authors: Benavides
authors: Miguel
authors: M
authors: Fuertes
authors: Carlos
authors: C
authors: García-Pariente
authors: Javier
authors: J
authors: Otaola
authors: Laetitia
authors: L
authors: Delgado
authors: Javier
authors: J
authors: Giraldez
authors: Juan Francisco
authors: JF
authors: García Marín
authors: M
authors: M
authors: Carmen Ferreras
authors: Valentín
authors: V
authors: Pérez
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D002490:Central Nervous System / Q000473:pathology; D005260:Female; D008168:Lung / Q000473:pathology; D008297:Male; D008321:Mammary Glands, Animal / Q000473:pathology; D011021:Pneumonia, Progressive Interstitial, of Sheep / Q000473:pathology* / Q000821:virology; D012756:Sheep; D014790:Visna-maedi virus / Q000302:isolation & purification*
keywords: Maedi-visna; Neurological; Pathology; Respiratory; Sheep